4:45

Skills Training For Parents Of Adolescents With Anorexia Nervosa: Comparing Three Delivery Formats - Videoconference, Face-To-Face Workshops, And Online Guided Self-Help
Julia Klang¹, Michael Zeiler¹, Stefanie Truttmann¹, Jessica Jerabek¹, Helene Krauss¹, Konstantin Kopp¹, Janet Treasure², Andreas Karwautz¹, Gudrun Wagner¹
¹Medical University of Vienna, Vienna, Austria, ²King's College London, London, United Kingdom

Objectives: To compare the efficacy, adherence, and satisfaction of three delivery formats of skills training for parents of adolescents with Anorexia Nervosa. Methods: Parents received a skills training (SUCCEAT = Supporting Caregivers of Children and Adolescents with Eating Disorders in Austria) delivered in three different formats: videoconference (n=180), face-to-face workshops (n=95), and online guided self-help (n=90). Caregiver skills, parental eating disorder-related burden, psychopathology, and high expressed emotion were assessed using self-report questionnaires in a pre-post design. Results: Significant reductions were observed in parental burden, general distress, anxiety, depression, emotional overinvolvement, and criticism, as well as increased caregiver skills, independent of the intervention format. Adherence was highest in the videoconference format. Satisfaction with SUCCEAT was highest in the videoconference and face-to-face workshop formats. Active participation and interpersonal communication were highest in the face-to-face workshops. Discussion: SUCCEAT, a parental skills training for Anorexia Nervosa, is effective and feasible across all three formats. Videoconference delivery may combine advantages of face-to-face workshops and online guided self-help, resulting in high satisfaction, better adherence, and improved accessibility.

5:00

What Predicts Whether Brief Cognitive-Behavioural Therapy (Cbt-T) Works For Non-Underweight Patients With Eating Disorders?
Jessica Ellingham¹, Glenn Waller^1,2
¹University of Sheffield, Sheffield, United Kingdom, ²University of Warwick, Coventry, United Kingdom

Introduction: This study examined predictors of outcomes from brief cognitive-behavioural therapy (CBT-T) for non-underweight patients with eating disorders, using a large naturalistic sample. The aims were: To determine outcomes of CBT-T. To identify the role of pre-therapy characteristics and early change in predicting outcomes. Method: The sample consisted of 371 adults who entered CBT-T (ten sessions). All completed measures at sessions 1, 4 and 10, including eating pathology (EDE-Q and BMI); anxiety (GAD-7); and depression (PHQ-9). Intention to treat (GLMM) and completer analyses were used. Results: Of the 371 participants, 53.1% completed therapy. There were no factors that predicted attrition. In ITT analyses, patients showed significant changes in EDE-Q scores overall and between sessions 1-4 and 4-10, with large effect sizes and ending substantially below clinical cut-off. BMI did not change, whether for the group as a whole or for those with initial BMIs above 30 or 40, showing no moderating effect. Baseline scores (EDE-Q, BMI, PHQ-9, GAD-7) offered minimal prediction of outcome at end of therapy, whereas early change (session 1-4) in restraint and weight concerns were strong predictors of overall outcome. Conclusions: CBT-T replicated its strong effects for non-underweight patients, regardless of BMI status. Baseline characteristics were not relevant to outcome, but early change in restraint and weight concerns were strong predictors of outcome.

5:15

Beyond Either/Or: Real World Outcomes Of A Simultaneous Parent&Ndash;Adolescent Treatment For An/Aan
Marion E Roberts¹, Deborah Mitchison², Sarah Brandeis¹
¹University of Auckland, Auckland, New Zealand, ²University of Technology Sydney, Sydney, Australia

Treatment for adolescent anorexia nervosa (AN) and atypical AN (AAN) typically emphasises either parent-led modalities or individual therapy, with limited exploration of integrative approaches. This study evaluated outcomes of a dual-focus intervention combining parent-led refeeding with concurrent adolescent individual therapy, delivered in a split-session format. A prospective, single-arm naturalistic cohort study with pre–post assessment was conducted in routine clinical care, embedded within the TrEAT Registry. Consecutive consenting adolescent-parent dyads receiving Adolescent & Parent Treatment (APT) at a specialist outpatient clinic were enrolled. Twenty-five participants (M age = 16.09, SD = 1.83) were included; 68% had AN and 32% AAN. Families received a mean of 26 sessions (SD = 13.12) with 33.4% also accessing dietetics. Mean weight gain across treatment was 5.5 kg (~12 pounds: SD = 2.87). Age adjusted BMI percentile increased significantly, t(20) = -6.97, p <.001 (Mdiff = -21.71, 95% CI [-28.21, -15.22]), with a large effect (d= -1.52, 95% CI [-2.15, -0.88]) that held with Hedges’ correction (g = -1.46, 95% CI [-2.07, -0.85]). At discharge, 76% were remitted based on DSM-V criteria. Treatment completion was 68%, with a further 16% near-completers. This integrative approach demonstrated strong acceptability and favourable outcomes in a real-world setting. Data collection is ongoing, updated results will be presented. Further evaluation of integrative treatment models is warranted.

5:45

Use Of Glucagon-Like Peptide-1 Receptor Agonists In Patients With A History Of Eating Disorder Population &Ndash; A Retrospective Cohort Study
Yael D Lewis^1,2,3, Amir Krivoy ^2,3,4, Daniel Stein^3,5,6
¹Hadarim Eating Disorder Center, Shalvata Mental Health Center, Hod Hasharon, Israel, ²Mental Health Data Research Center, Clalit Health Services , Petach Tikva, Israel, ³Gray Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, ⁴Geha Mental Health Center, Petach Tikva, Israel, ⁵Pediatric Psychosomatic Department, Safra Children’s Hospital, Sheba Medical Center, Tel Hashomer, Israel, ⁶Eating Disorders Unit, Maayanei Hayeshua Medical Center, Bnei Brak, Israel

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have increasingly been used for weight loss treatment, yet their effects among individuals with eating disorders (EDs) remain uncertain. We aimed to investigate GLP-1RAs use in patients with a prior ED. Using a retrospective cohort method, we studied patients insured by Clalit Health Service (CHS) in Israel. Between 2010 and 2023, 218,457 patients were prescribed a GLP-1RA. Of these 1,753 had an ED diagnosis: 6% had anorexia nervosa, 15% bulimia nervosa, and 79% a non-specific ED diagnosis. Baseline body mass index (BMI) before GLP-1RA initiation was higher in the ED group than in the non-ED group (mean [SD], 36.5 [7.2] vs 34.0 [5.7]; p<0.001). Within ED subtypes, patients with anorexia nervosa had a lower baseline BMI (34.0 [6.0]) than those with bulimia nervosa or unspecified ED (both 37.0 [7.0]; p<0.001). Change in BMI after treatment did not differ significantly between ED and non-ED groups (−1.42 [3.2] vs −1.33 [2.7]). Patients with ED were less likely to be diagnosed with diabetes mellitus (DM) than those without ED (37% vs 63%; p<0.001). These real-world data suggest that weight-loss effectiveness of GLP-1RAs is comparable regardless of ED history. The higher baseline BMI and lower rates of DM in GLP-1RA recipients with ED may indicate greater treatment-seeking for obesity in this population. Further prospective research with ED-specific symptom measures is warranted in order to establish GLP-1RAs on ED symptoms and course.

5:30

The Impact Of Behavioural Weight Management On Eating Disorder Symptoms For Adolescents And Adults: A Systematic Review And Individual Participant Data Pairwise And Network Meta-Analysis, Findings From The Edit Collaboration
Hiba Jebeile^1,2, Sol Libesman³, Louise A Baur^1,4, Sarah P Garnett¹, Kylie E Hunter³, Isabelle R Jardine¹, Rabia Khalid^1,2, Sasha J Lorien¹, Hannah Melville¹, David Nguyen³, Anna Lene Seidler^3,5,6, Natalie B Lister^1,2, on behalf of the EDIT Collaboration¹
¹Sydney Medical School, The University of Sydney, Westmead, Australia, ²Charles Perkins Centre, The University of Sydney, Camperdown, Australia, ³National Health and Medical Research Council Clinical Trials Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia, ⁴Weight Management Services, The Children’s Hospital at Westmead, Westmead, Australia, ⁵Department of Child and Adolescent Psychiatry, University Medical Centre Rostock, Rostock, Germany, ⁶German Center for Child and Adolescent Health (DZKJ), partner site Greifswald/Rostock, Rostock, Germany

Introduction: Eating disorders (ED) are prevalent in people with higher weight. We examined change in ED symptoms after behavioural weight management interventions, overall and by intervention intensity.
Methods: Databases and trial registries were searched to March 2022. Individual participant data (IPD) were requested from RCTs of behavioural interventions in adolescents or adults with ED outcomes. IPD analyses assessed change in global ED and binge eating symptoms between baseline and latest timepoint: 1) intention-to-treat, two-stage, random effects pairwise meta-analysis to examine effects of any intervention vs control; 2) two-stage, random effects contrast-based network meta-analysis comparing interventions of varying intensity and controls.
Results: IPD from 36 trials (k; n=4,455) were included. Compared to control, pairwise meta-analyses found a reduction in ED symptoms (k=2, n=108; standardised mean difference [95%CI] -0·18 [-0·25, -0·12], 𝜏=0.00, moderate certainty) and no change in binge eating (k=2, n=458, -0·15 [-0·42, 0·13], 𝜏=0·15, moderate certainty). Network meta-analyses (k=9, n=961) found no differences between no-treatment control and low (-0·23 [-0·57, 0·12]) and medium-intensity (-0·23 [-0·52, 0·07]) and a reduction for high-intensity interventions (-0·34 [-0·66, -0·02]) for ED symptoms, and no differences for binge eating.
Conclusion: Overall, behavioural interventions did not increase ED symptoms. Understanding individual variability is needed.

4:30

Learning To Be (Un)Safe: Differences Between Patients With Anorexia Nervosa, At‑Risk Individuals, And Healthy Controls In Disorder‑Specific Vs. Generic Fear Learning
Ludovica Natali, Valentina Cardi
University of Padova, Padova, Italy

The study examined whether altered aversive learning contributes to anorexia nervosa (AN) and whether such alterations are specific to eating related cues. Seventy-nine female participants were assigned to three groups: AN patients (n=26), at risk individuals with subthreshold symptoms (n=27), and healthy controls (n=26). They completed two differential three phase fear conditioning tasks: one using a generic aversive unconditioned stimulus (US) and one using a disorder specific US representing feared eating consequences. Two neutral shapes served as conditioned stimuli: the CS+ was reinforced on 75% of trials, while the CS− was never reinforced. After each trial, participants rated US expectancy. In the disorder specific task, AN patients showed higher threat expectancy for the CS− during acquisition (vs. controls and at risk) and for both CS− (vs. controls and at risk) and CS+ during extinction (vs. controls). At risk individuals showed increased CS+ expectancy (vs. controls) during acquisition and extinction. In the generic task, AN patients showed elevated CS− expectancy during acquisition and extinction (vs. controls and at risk), while at risk participants showed higher CS+ expectancy only during acquisition (vs. controls). Overall, AN patients displayed pervasive threat generalization and impaired safety learning, whereas at risk individuals showed enhanced but more cue specific threat acquisition, suggesting distinct learning alterations across the AN spectrum.

4:15

Effects Of Neurofeedback On Approach Biases Toward Food In Binge-Eating Disorder
Ben Schreglmann¹, Ricarda Schmidt¹, Michael Lührs^2,3, Anja Hilbert¹
¹Integrated Research and Treatment Center AdiposityDiseases, Behavioral Medicine Research Unit, Department of Psychosomatic Medicine and Psychotherapy, Leipzig University Medical Center, Leipzig, Germany, ²Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands, ³Brain Innovation B.V., Maastricht, Netherlands

Introduction Neurofeedback (NF) targeting food-specific neurophysiological activity is a promising treatment approach for binge-eating disorder (BED), yet its effects on approach biases toward food and potential mechanisms of change remain unclear. Methods In a preregistered secondary analysis of an exploratory RCT, 72 adults with BED were randomized to 12-session food-specific electroencephalography (EEG) NF, real-time functional near-infrared spectroscopy (rtfNIRS) NF, or waitlist. Approach biases toward food (Approach Avoidance Task), neurophysiological activity, and objective binge-eating (OBE) frequency were assessed at baseline, posttreatment, and 6-month follow-up, and explored using Bayesian models. Results There was no evidence for group-level changes in approach biases across timepoints. However, in EEG-NF, reductions in high-calorie food approach bias were associated with reductions in fronto-central high beta activity. In rtfNIRS-NF, reductions in low-calorie food approach bias were associated with increases in prefrontal oxygenation and reductions in OBE frequency. Posterior probabilities of moderate-to-large effects ranged from 0.69 to 0.83. Conclusions Reductions in the tendency to approach high-calorie food rather than to avoid it may be more closely tied to improvements in attentional regulation, while reductions in approach tendencies toward low-calorie food may be more closely tied to improvements in cognitive control and show stronger links to OBE reduction.

4:30

Neural Alterations During Incentive Processing Of Taste In Adolescents With Anorexia Nervosa
Christina E. Wierenga, Christine Fennema-Notestine, Megan Martinho, Amanda Bischoff-Grethe
University of California San Diego, San Diego, CA, United States

Introduction: Dysregulation of motivational brain systems contributes to anorexia nervosa (AN), but how neural function differs by restricting (AN-R) and binge eating/purging (AN-BP) subtypes is unknown. Methods: This study compared neural response to incentive processing of pleasant and unpleasant taste between adolescent girls with AN-R (n=49), AN-BP (n=22), and healthy controls (HC; n=50) who underwent fMRI while performing a modified incentive delay task. Data were analyzed with linear mixed effects models to examine the interaction of group x phase (anticipation, receipt) x tastant (juice, neutral, salty tea) in motivational circuitry, including the insula, striatum, and prefrontal cortex. Results: Significant 3-way interactions (voxel-wise p<.002, clusterwise α<.0125) were detected in all regions of interest. For pleasant taste, AN-R had lower receipt and higher anticipation response in the left insula and putamen, with the opposite pattern of response observed in AN-BP. AN-BP also had lower anticipation and higher receipt response for unpleasant taste in the insula. In AN-BP, lower putamen juice receipt response was associated with increased binge eating severity, suggesting links between striatal reward blunting and symptom severity. Conclusions: Findings support subtype-specific alterations in taste incentive processing with differences in hedonic processing and approach motivation that may contribute to distinct symptom presentations that differentiate AN-R and AN-BP.

4:45

Dissociable Hippocampal Remodeling In Anorexia Nervosa: Reversible Volume Loss, Persistent Gyrification Reduction, And Parallel Molecular Evidence From A Translational Rat Model
Enrico Collantoni^1,2, Massimiliano Facca^2,3, Valentina Meregalli¹, Sofia Taddini^1,2, Letizia Rapini⁴, Francesca Mottarlini⁴, Angela Favaro^1,2, Lucia Caffino⁴
¹Department of Neuroscience, University of Padova, Padova, Italy, ²Padova Neuroscience Center, University of Padova, Padova, Italy, ³Department of Information Engineering, University of Padova,, Padova, Italy, ⁴Department of Pharmacological and Biomolecular Sciences ‘Rodolfo Paoletti’, Università degli Studi di Milano, Milano, Italy

Hippocampal alterations in anorexia nervosa (AN) likely span macroscale morphology and molecular remodeling, yet they remain disjoint in the literature. We present the first surface-based subfield morphometry of the AN hippocampus, with molecular profiling in a translational rat model. T1-weighted MRI from 84 acute AN, 19 weight-recovered (AN-R), and 84 controls underwent HippUnfold for volume, surface area, thickness, gyrification at global/subfield/vertex-wise levels. In the activity-based anorexia (ABA) model, hippocampal markers of neuroaxonal injury (NfL), extracellular matrix (ECM) remodeling (MMP9, Hapln1, Ncan), synaptic plasticity (Nrn1, Nptx2), and astrogliosis (GFAP) were quantified at acute and recovery phases. Thickness was preserved. Global volume was reduced bilaterally in acute AN (-3%, pSidak<0.05); surface area was reduced in AN-R (left, -5%, pSidak=0.034). Gyrification was reduced in acute AN in bilateral CA1 (-3.9%/-3.7%) and CA4 (-5.4%/-4.2%) and persisted in AN-R (left CA1 -5.8%, CA4 -5.6%; pFDR<0.03). In ABA, NfL and MMP9 rose acutely (p<0.01) and normalized after recovery; Hapln1, Ncan, Nrn1, Nptx2 remained reduced and GFAP elevated at both phases (p<0.001). In AN, hippocampal alterations dissociate: volume/surface area partially recover, while CA1/CA4 gyrification persists. The parallel ABA pattern—neuroaxonal recovery with enduring synaptic/ECM and astroglial disruption—suggests incomplete molecular remodeling underlying residual vulnerability.

5:30

Low Admission Leptin And Triiodothyronine Predict Refeeding Response In Adolescents Hospitalized With Atypical Anorexia Nervosa From The Individualized Study Of Refeeding To Optimize Inpatient Gains (Istrong) Trial.
Arjun S. Mehta¹, Amanda E. Downey^1,2, Sasha Gorrell², Louie M. Swander¹, Jing Cheng¹, Cynthia J. Kapphahn³, Siena S. Vendlinski⁴, Sara M. Buckelew¹, Anna Kreiter³, Barabara Moscicki⁵, Audrey Hernando¹, Kyla Kent, Kristene Hossepian³, Brooke Marsal, Paige Wright³, Daniel Le Grange², Megan Vo, Neville H. Golden³, Andrea K. Garber¹
¹Department of Pediatrics, University of California, San Francisco, San Francisco, CA, United States, ²Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, San Francisco, CA, United States, ³Department of Pediatrics, Stanford University, Palo Alto, CA, United States, ⁴Department of Psychology, University of South Florida, Tampa, FL, United States, ⁵Department of Pediatrics, University of California, Los Angeles, Los Angeles, CA, United States

Introduction: Body weight has limited utility for assessment and monitoring of malnutrition in adolescents with atypical anorexia nervosa (AAN;≥85% median BMI [%mBMI]), who develop medical instability at a higher BMI, and restore stability in hospital with less weight gain than typical AN. Thus, we examined associations between weight history, hypometabolism, and short-term hospital outcomes. Methods: Secondary analysis of iStRONG RCT data. Predictors: admit leptin, triiodothyronine (T3); magnitude of weight loss defined as highest lifetime %mBMI – admit %mBMI. Outcomes: length of stay (LOS), days to medical stability (heart rate [HR]≥45 bpm, systolic blood pressure [SBP]≥90 mmHg, temperature≥35.6°C, orthostatic ΔHR≤35 bpm, and ΔSBP≤20 mmHg), kcal to stability, and HR nadir. Linear regressions adjusted for highest lifetime %mBMI and treatment assignment. Results: Among 67/74 participants: mean age=15.1(1.8), %mBMI=96.0(10.9), highest %mBMI=132.9(26.3), leptin=4.9(4.9) ng/mL [ref: 3.4-13], and T3=1.0(0.4) nmol/L [ref:1.1-2.7]. Lower leptin and T3 were strongly associated with greater magnitude of loss (p<.005), not body weight, and predicted longer LOS, more days and kcal to stability, and HR nadir (p<.02). Conclusions: Patients with AAN and greater magnitude of weight loss presented with deeper hypometabolism and required more intensive refeeding, regardless of body weight. Findings support the utility of biomarkers to monitor nutritional rehabilitation in AAN.

5:45

Neural Correlates Of Emotion Conflict Processing In Adolescent Girls And Young Women With Binge-Eating Psychopathology
Kelsey E. Hagan¹, Nandini Datta², Victoria Franco³, Noam Weinbach⁴, James Lock², Cara Bohon⁵
¹Virginia Commonwealth University, Richmond, VA, United States, ²Stanford University, Stanford, CA, United States, ³McGill University, Montreal, QC, Canada, ⁴University of Haifa, Haifa, Israel, ⁵Manta Cares, San Francisco, CA, United States

Objectives: Emotion dysregulation has been robustly implicated in binge eating (BE). However, extant research has focused on the role of explicit (vs. implicit) emotion regulation in BE psychopathology. Here, we examined the neural correlates of implicit emotion regulation and their association with BE frequency in adolescent girls and young women with BE. Methods: Participants (63 BE, 32 controls, ages 14-35) completed an emotional conflict (Stroop) task during fMRI scanning. Trial-by-trial analyses modeled current and preceding trial congruency. Primary contrasts were iI>cI (conflict adaptation) and iC>cC (persistence of conflict-related processing). Groups were compared via voxel-wise whole-brain analysis (Z>3.1, cluster-level FWE p=.05). Mean percent signal change in bilateral amygdala, rostral anterior cingulate cortex (rACC), and caudal anterior cingulate cortex (cACC) was correlated with weekly BE frequency.  Results: The BE group showed greater left cACC engagement during conflict adaptation, t(93)=-1.97, p=.05. BE frequency negatively correlated with right rACC activation during conflict adaptation, r(61)=-.28, p=.02. Conclusion: Adolescent girls and young women with BE appear to work harder to monitor emotional conflict (via the left cACC) than their unaffected peers, yet they exhibit a diminished ability to recruit the right rACC (an affective regulatory region) as BE increases. This suggests that implicit regulatory systems may become less efficient with increasing BE severity.

4:15

Predictors Of Change In Eating Disorder Symptoms Following Behavioural Weight Management For Adolescents And Adults: Prognostic And Prediction Models With Individual Participant Data From The Edit Collaboration
Hiba Jebeile^1,2, Sol Libesman³, Louise A Baur^1,4, Sarah P Garnett¹, Kylie E Hunter³, Isabelle R Jardine¹, Rabia Khalid^1,2, Sasha J Lorien¹, Hannah Melville^1,2, David Nguyen³, Anna Lene Seidler^3,5,6, Natalie B Lister^1,2, on behalf of the EDIT Collaboration¹
¹Sydney Medical School, The University of Sydney, Westmead, Australia, ²Charles Perkins Centre, The University of Sydney, Camperdown, Australia, ³National Health and Medical Research Council Clinical Trials Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia, ⁴Weight Management Services, The Children’s Hospital at Westmead, Westmead, Australia, ⁵Department of Child and Adolescent Psychiatry, University Medical Centre Rostock, Rostock, Germany, ⁶German Center for Child and Adolescent Health (DZKJ), partner site Greifswald/Rostock, Rostock, Germany

Introduction: Individual change in eating disorder (ED) symptoms after behavioural weight management varies. We aimed to identify predictors of change in ED symptoms for adolescents and adults. Methods: Individual participant data (IPD) from 36 RCTs (n=4,455) of behavioural interventions assessing ED were included. Prognostic associations between baseline factors and change in global ED and binge eating (BE) symptoms at the latest timepoint were examined separately using two-stage random-effects IPD meta-analysis. Multivariable prediction models were developed using penalised regression (LASSO) and multilevel modelling. Results: Individuals tended towards reduced symptoms. Separate prognostic meta-analyses found female sex, lower self-esteem, quality of life and body image were prognostic of smaller reductions in ED symptoms. Being from a racial/ethnic majority group, higher scores on emotional eating, stress and disinhibition were prognostic of smaller reductions in BE. On a reduced variable set, multivariable prediction models used data from 13 (n=1,322) and 11 trials (n=1,381) for global ED and BE, respectively. Models explained 34% and 46% of the variance for ED and BE symptoms, respectively, with baseline ED, sex and depression symptoms the strongest predictors. Conclusion: Several factors affected ED and BE symptoms. These were associated with an attenuated reduction and not a true increase over time. ED and depression screening may identify those needing support.

5:00

Noradrenergic Control Of Neurobehavior In Human Binge-Eating Disorder And Obesity
Swen Hesse^1,2, Michael Rullmann¹, Franziska Zientek¹, Antonia Haddenhorst^2,3, Helen Vöhringer^2,3, Lisa-Marie Okhof^2,3, Georg-A. Becker¹, Andreas Schildan¹, Adrienne S. Juarascio⁴, Guido K. W. Frank^5,6, Osama Sabri¹, Anja Hilbert^2,3
¹Department of Nuclear Medicine, University of Leipzig Medical Center, Leipzig, Germany, ²Integrated Research and Treatment Center (IFB) Adiposity Diseases, University of Leipzig Medical Center, Leipzig, Germany, ³Behavioral Medicine Research Unit, Department of Psychosomatic Medicine and Psychotherapy, University of Leipzig Medical Center, Leipzig, Germany, ⁴Department of Psychology, Drexel University, Philadelphia, PA, United States, ⁵University of California San Diego, UCSD Eating Disorder Center, San Diego, CA, United States, ⁶Rady Children's Hospital San Diego, San Diego, CA, United States

Aim: The neurobehavioral underpinnings of binge-eating disorder (BED) co-occurring with obesity (OB) are largely unknown. We hypothesize that BED is a disorder with dysfunctional emotion regulation (ER), associated with alterations in the central noradrenergic (NA)-modulated networks, i. e. lower NA transporter (NAT) availability, in individuals with OB and BED (OB+BED) and in OB without BED (OB-BED) compared to NW, with these changes being more pronounced in OB+BED. Methods: NAT availability was quantified using [¹¹C]methylreboxetine and simultaneous positron emission tomography-functional magnetic resonance imaging in OB+BED (22, 15f, 40±12 yrs, 34±5 kg/m²), OB-BED (24, 21f, 40±10 yrs, 36±6 kg/m²), and NW (13, 11f, 37±12 yrs, 22±2 kg/m²). Results: We found lower NAT binding potential in the thalamus (eg, left: NW vs. OB-BED vs. OB+BED 0.73±0.13 vs. 0.66±0.1 vs 0.62±0.12; ANOVA p=0.028) together with higher connectivity strength between the hypothalamus and the ventromedial prefrontal cortex in NW compared with OB (p<0.001 uncorr). Conclusions: These results demonstrate the expected lower NAT availability in OB+BED and OB-BED compared with NW and abnormalities in a noradrenergic thalamus/hypothalamus network that involves prefrontal limbic areas. Ongoing research examines whether these abnormalities are modifiable by intervention focusing on improving ER, specifically in OB+BED, in order to identify predictive imaging biomarkers for tailored treatments in individuals with BED and OB.

5:15

Pre- And Perinatal Risk Factors Of Avoidant/Restrictive Food Intake Disorder (Arfid): A Registry-Based Twin Study In Sweden
Liv Hog¹, Afrouz Abbaspour¹, Ralf Kuja-Halkola¹, Henrik Larsson^{1, 2}, Sebastian Lundström^{3, 4}, Paul Lichtenstein¹, Ida A. K. Nilsson^{5, 6}, Mark J. Taylor¹, Cynthia M. Bulik^{7, 8}, Lisa Dinkler¹
¹Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden, ² School of Medical Sciences, Örebro University, Örebro, Sweden, ³Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden, ⁴Region Skåne, Psychiatry, Habilitation & Aid, Child and Adolescent Psychiatry, Malmö, Sweden, ⁵Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden, ⁶Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden, ⁷Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ⁸Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States

Introduction: Avoidant/restrictive food intake disorder (ARFID) is a feeding and eating disorder leading to severe physical and psychosocial impairment due to limited quantity or variety of food intake. Little is known about the influence of pre- and perinatal risk factors on ARFID development. Methods: In a sample of 33,732 twins aged 9-12 years from the Child and Adolescent Twin Study in Sweden, we identified ARFID and pre- and perinatal risk factors using parent reports and national health registries. We performed univariable logistic regressions of pre- and perinatal factors on ARFID, adjusting for sex and birth year. To identify associations specific to ARFID, we additionally adjusted for autism and ADHD. Results: ARFID was present in 2.16% of the sample. We found higher odds of ARFID for low gestational age (OR=3.53) and birth weight (OR=2.53), intubation (OR=3.48), tube feeding (OR=1.36), digestive conditions (OR=4.15), infections (OR=2.02), low parental education (OR=1.90-2.08), and immigration (OR=1.23-1.94), among others. After adjustment for autism and ADHD, most associations were attenuated but remained statistically significant. Conclusion: This study indicates a contribution of pre- and perinatal risk factors to ARFID development, even when accounting for related conditions previously associated with such factors. Identifying ARFID risk factors may improve understanding of its etiology and health outcomes by informing possible prevention and early intervention targets.

P100

Psychometric Validation Of Eating Behavior Risk, An Instrument Not Solely Weight‑Centric Measure For Identifying Disordered Eating Behaviors In The General Population
Lara Algueró¹, Manuel Trinidad-Fernández², José CE Serrano¹, Francesca Golfín⁵, Cristina Bravo^2,3,4, Gina Badia^5,6, Didier Hernández-García^5,6,7
¹Department of Experimental Medicine, University of Lleida, Lleida, Spain, ²Department of Nursing and Physiotherapy, University of Lleida, Lleida, Spain, ³Grup d’Estudis Societat, Salut, Educació i Cultura, GESEC, Department of Nursing and Physiotherapy, University of Lleida, Lleida, Spain, ⁴Health Care Research Group (GRECS), Lleida Institute for Biomedical Research Dr. Pifarré Foundation, IRBLleida, Lleida, Spain, ⁵Eating Disorders Unit, Santa María University Hospital, Health Services Management. , Lleida, Spain, ⁶Biological Foundations of Mental Disorders Group, Institute for Biomedical Research of Lleida (IRBLleida), Lleida, Spain, ⁷Department of Medicine, University of Lleida, Lleida, Spain

Background: Disordered eating behaviors (DEBs) are increasingly prevalent and often precede eating disorders. Existing screening tools focus on clinical symptoms or weight‑centric constructs. There is a need for an instrument that is not solely weight-centric to identify DEBs in non-clinical settings. The aim of this study was to develop a brief questionnaire to detect DEBs in the general population. Methods: Eating Behavior Risk (EBR) questionnaire was developed following COSMIN guidelines through item generation, expert content validation, and a pre‑survey with 40 adults. Psychometric testing was conducted in 203 participants. Structural validity was examined through exploratory factor analysis (EFA). Internal consistency, test–retest reliability (ICC), measurement error (SEM, MDC95), and convergent validity were assessed. Results: Content validity was excellent (S‑CVI/Ave = 0.95). EFA supported a three‑factor structure—body image concerns, dysregulated eating, and rigid cognitive restraint—with a KMO of 0.88 and 42% explained variance. Test–retest reliability was strong (ICC = 0.94), convergent validity with the EAT‑26 was moderate (r = 0.64), and discriminative performance was high (AUC = 0.83). Conclusion: EBR shows solid preliminary validity and reliability as a not solely weight-centric tool for detecting DEBs. Further studies should confirm its structure through confirmatory factor analysis in independent samples.

P101

Using Ecological Momentary Assessment And Wearable Sensors To Predict Restrictive Eating In Anorexia Nervosa In Daily Life
Emma De Schuyteneer¹, Emily Presseller², Nattapong Thammasan³, Jeroen Hamers³, Elske Vrieze¹
¹Mind Body Research, KU Leuven, Leuven, Belgium, ²The Center for Technology and Behavioral Health, Lebanon, NH, United States, ³Imec NL/OnePlanet, Wageningen, Netherlands

Introduction: Dietary restriction is the core behavioural mechanism maintaining AN, yet predicting when it occurs remains underexplored. Negative affect is a potential risk factor for restriction, and EMA can capture this in real time. Ecological physiological assessment (EPA) complements this by measuring autonomic arousal, offering an objective, minimally intrusive signal. Methods: People with AN completed a two-week EMA protocol (8 prompts/day) while wearing an Empatica watch. Data collection is ongoing (n = 68, 3499 meals, of which 2613 restricted). Heart rate (HR), skin temperature (ST) and electrodermal activity (EDA) features will be extracted using 5-min windows across the hour before each meal. Classification and regression models were compared across EMA-only, EPA-only, and combined predictors, using regression, random forest, and support vector machines. We hypothesised that EMA+EPA > EMA > EPA. Results: Preliminary results (HR and ST only, EDA pending) show the best EMA model (random forest, AUC = 0.714) significantly outperformed the best EPA model (AUC = 0.521, p<0.001), flagging 8 in 10 restrictive meals. Sensor data did not improve performance (AUC = 0.670). Regression models failed to predict restriction severity (R² <0.05). Discussion: In these preliminary analyses, self-reported emotions outperformed physiological signals. Adding EDA may improve performance. These are a first step toward digital interventions that deliver support before restriction occurs.

P102

Development And Preliminary Validation Of A Novel Eating Disorders Screening Tool For Children And Adolescents
Andrea B. Goldschmidt¹, Lisa M. Ranzenhofer², Anna Tanner³, Joan C. Han⁴, Denise E. Wilfley⁵, Daphne Lew⁵, Megan E. Byrne⁶, Marian Tanofsky-Kraff⁷
¹University of Pittsburgh School of Medicine, Pittsburgh, PA, United States, ²University at Buffalo, Buffalo, NY, United States, ³Emory University School of Medicine, Atlanta, GA, United States, ⁴Nationwide Children's Hospital, Columbus, OH, United States, ⁵Washington University School of Medicine, St. Louis, MO, United States, ⁶National Institutes of Health, Bethesda, MD, United States, ⁷Uniformed Services University of the Health Sciences, Bethesda, MD, United States

There are few screeners for pediatric eating disorders (EDs), and the most widely used tools do not cover the range of symptom presentations, perform less well for youth with certain demographic characteristics (males, youth with high weight), and do not involve caregivers, important collateral sources of information. Our group developed a brief ED screener (Screening Kids And Teens for Eating disorders; SKATE) which we administered, along with developmentally appropriate versions of the Eating Disorder Examination interview (EDE) and questionnaire (EDE-Q), to 146 youth/caregiver dyads (8-18y) presenting for intervention and non-intervention research studies at two Mid-Atlantic academic medical centers. Child SKATE items were moderately to highly concordant with EDE items assessing compensatory behaviors (overall agreement=72.5-96.3%) and loss of control eating (overall agreement=88.1%), and with EDE-Q Shape and Weight Concerns subscales (r range=.69-.71; p<.001) and global score (r=.76; p<.001). Caregiver SKATE items were strongly concordant with EDE items assessing compensatory behaviors (overall agreement=92.6-97.8%) but less so for loss of control eating (overall agreement=78.8%). Caregiver SKATE items had moderate agreement with EDE-Q Shape and Weight Concerns subscales (r range=.54-.55; p<.001) and global score (r=.53; p<.001). Next steps include validation in larger, more representative clinical and community samples, with consideration of implementation factors for future roll-out.

P103

Clinical Staging In Eating Disorders: A Scoping Review And Qualitative Investigation
Lucy Hyam¹, Lucy Gallagher¹, Carina Kuehne¹, Melissa-Claire Daugelat^2,3, Melissa Pehlivan⁴, Regan Mills⁵, Isinsu Karabicak⁶, Azza Elsheikh⁶, Anna Carnegie⁷, Karina Allen^1,8, Ulrike Schmidt^1,8
¹Centre for Research in Eating and Weight Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom, ²Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tuebingen, Tuebingen, Germany, ³Centre of Excellence for Eating Disorders Tuebingen (KOMET), Eberhard Karls University Tuebingen, Tuebingen, Germany, ⁴InsideOut Institute for Eating Disorders, University of Sydney and Sydney Local Health District, Sydney, Australia, ⁵Department of Psychology, University of Bath, Bath, United Kingdom, ⁶Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom, ⁷Social Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom, ⁸Eating Disorders Outpatients Service, South London and Maudsley NHS Foundation Trust, London, United Kingdom

Introduction: There is growing interest in the utility of clinical staging for eating disorders (EDs). This work explored staging through a scoping review of the evidence and a qualitative study. Methods: The review selected studies using pre‑published criteria and summarised them via narrative synthesis. The qualitative study involved semi‑structured interviews and focus groups with 21 participants who had lived experience or were carers or ED clinicians. Reflexive thematic analysis was used to identify themes. Results: Sixty studies were included in the review, largely comparing early versus longstanding ED stages. Middle stages were poorly defined, staging was typically based on duration or behavioural/clinical markers, and few biological studies were found. Qualitative findings suggested staging is a broadly meaningful way to conceptualise EDs, but participants desired more flexibility, as EDs carry non-linear trajectories, with comorbidities, medical complications, and system‑level barriers to timely care shaping stage progression or expression. A new staging model is proposed in line with these findings. Conclusions: Early and later‑stage EDs appear to differ in presentation and treatment needs, but little is known about biological markers of stage progression. To advance clinical staging, large scale prospective longitudinal studies are needed that map illness trajectories and stage progression through multi-modal bio-psycho-social assessments.

P104

Factor Structure Of The Nine-Item Arfid Screen In Adolescent And Young Adult Patients With Chronic Pain
Nicole K. Johnson¹, Brianne N. Richson^1,2, Emily Auger^3,4, Leslie A. Sim⁴
¹Division of Biobehavioral Research, Sanford Health, Fargo, ND, United States, ²Department of Psychiatry and Behavioral Science, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, United States, ³School of Social Work, University of Denver, CO, United States, ⁴Department of Psychiatry and Psychology, Mayo Clinic College of Medicine and Science, Rochester, MN, United States

Introduction: Despite symptom overlap (e.g., food avoidance due to gastrointestinal complaints) and co-occurrence between avoidant/restrictive food intake disorder (ARFID) and chronic pain, research has yet to validate ARFID measures in youth with chronic pain. Methods: We evaluated the factor structure of the Nine-Item ARFID Screen (NIAS) in patients aged 13-23 (M=16.42, SD=1.96; N=366) entering a pain rehabilitation program. Twelve percent met criteria for ARFID, and 10% met criteria for another eating disorder. Results: The NIAS scales showed good internal consistency (α=.83-.88). Confirmatory factor analysis revealed the original NIAS 3-factor model (Picky Eating, Low Appetite, Fear) fit well, (robust) χ²(24)=109.17, p<.001, CFI=.96, TLI=.94, SRMR=.05. However, RMSEA was suboptimal (.11 [.09, .14]), leading us to examine modification indices showing Low Appetite items 4 and 6 may also reflect Fear. Indeed, 53% of the sample had recurrent pain-related nausea/vomiting, suggesting Low Appetite and Fear items may both be salient. A modified model with items 4 and 6 loading onto Low Appetite and Fear improved model fit, ∆SBχ²=27.34, p<.001. However, item 4 and 6’s Fear loadings were low (≤|.20|), and item 4’s Fear loading was negative. Conclusions: Results suggest the original NIAS factor structure can be retained for use in young patients with chronic pain. Studies are needed to clarify the utility of low appetite as a marker of ARFID pathology in co-occurring chronic pain.

P105

Bioimpedance Analysis In Adolescents With Anorexia Nervosa: Clinical Insights From Case-Based Application
Konstantin Kopp, Helene Krauss, Julia Klang, Dunja Mairhofer, Nina Lukasser, Hanna-Sophie Salzburger, Michael Zeiler, Gudrun Wagner, Andreas Karwautz
Medical University of Vienna, Department for Child and Adolescent Psychiatry, Eating Disorder Unit, Vienna, Austria

Introduction Bioimpedance analysis (BIA) is increasingly used to monitor body composition in anorexia nervosa (AN), yet its application in adolescents in clinical practice requires careful interpretation.
Methods Clinical observations from five adolescents with AN treated in an inpatient setting between 2023 and 2025 will be reported. BIA measurements were performed approximately every two weeks. Case-based analyses focused on longitudinal changes and potential sources of bias.
Results BIA provided clinically useful information on changes in body composition over time, particularly regarding fat mass and phase angle. Case examples illustrated discrepancies between weight gain and body composition, including patients with low body fat improving over time and others showing stable fat mass despite weight gain. In one patient, changes in body fat appeared to coincide with observable changes in the clinical presentation, including compulsive exercise. In addition, several measurements appeared implausible in the clinical context, likely due to fluid manipulation, including one case of severe water intoxication. These observations highlighted that longitudinal trends were more informative than isolated measurements.
Conclusions BIA can be a useful adjunct for monitoring treatment progress in adolescents with AN when interpreted cautiously and in clinical context. Emphasis should be placed on trends rather than single measurements.

P106

Standardised Minimum Dataset Evaluation For Paediatric Eating Disorder Services
Yafit Kushner^1,2,3, Michele Yeo^1,2, Diana Truong¹, Amanda Eccles¹, Joyce Seitzinger¹, Cate Rayner^1,2
¹The Royal Children's Hospital Melbourne, Melbourne, Australia, ²Murdoch Children's Research Institute, Melbourne, Australia, ³The University of Melbourne, Melbourne, Australia

Eating disorders are severe mental health conditions affecting up to 3% of the population. Restrictive eating disorders, particularly anorexia nervosa, have the highest mortality of any psychiatric illness. The rising prevalence in children and adolescents, alongside complex comorbidities and long-term impacts, highlights the need for consistent outcome measurement and longitudinal data collection to inform care. To address this, the Royal Children’s Hospital Eating Disorders Service developed an evidence-based evaluation program fully integrated within the electronic medical record. Informed by research, clinical expertise, and lived experience, the program systematically captures demographic, clinical, and outcome data. It employs comprehensive measures encompassing eating disorder features, mental health comorbidities, neurodiversity, quality of life, family functioning, attachment-related anxiety and avoidance, and adverse childhood experiences. Early implementation has demonstrated feasibility, clinical utility, and efficiency, streamlining data capture and supporting patient-centred, data-driven care. To our knowledge, this represents the first implementation of national and international Minimum Dataset recommendations for eating disorders in a tertiary hospital setting, and the first paediatric application globally. This program provides a scalable framework to enhance outcome monitoring, inform clinical decision-making, and strengthen collaborative research.

P107

The Uk-Wide Eating Disorders Clinical Research Network (Edcrn): Learning From The First 300 Adult Patients
Lu Qi¹, Rosemary Chandler-Wilde¹, Anna Carnegie¹, Gerome Breen¹, Karina Allen^{1, 2}, and the wider EDCRN team^{1, 2}
¹King's College London, London, United Kingdom, ²South London and Maudsley NHS Foundation Trust, London, United Kingdom

Introduction: The EDCRN is supporting UK eating disorder (ED) services to collect standardised data on presentation, treatment and outcomes. The Network serves as a clinical quality registry and aims to facilitate improved outcomes and novel biopsychosocial research. This study focused on (a) the acceptability and feasibility of the EDCRN dataset and (b) baseline clinical characteristics. Methods: Data were collected via the secure EDCRN digital platform. Intake data were provided by 300 adults seen in 6 ED services over a 1-year period. Results: 92% (n=276) of patients identified as female and 78% (n=234) as white. Mean age was 30.6yrs (SD 11.8) with a mean age of ED onset of 18.4yrs (SD 8.8). The acceptability of the dataset was high: 98% (n=293) of patients completed at least 1 questionnaire measure, 74% (n=220) completed all 16 ‘core’ measures, and 67% (n=201) completed at last 1 ‘optional’ measure. The most common ‘optional’ measures were somatic difficulties, ADHD traits and PTSD symptoms. 82% of patients reported at least moderate depressive symptoms, 69% at least moderate anxiety symptoms, and 40% clinically significant obsessive-compulsive disorder symptoms. 33% reported high autistic traits. Conclusions: We provide evidence for the acceptability and feasibility of standardised data collection in UK ED services. Results provide insight into presenting characteristics and treatment needs. Diagnostic differences will be summarised in our presentation.

P108

Delphi Survey On Chronic, Persistent Or Long-Lasting Forms Of Anorexia Nervosa
Ulrich Voderholzer^1,2,3, Alessio M. Monteleone⁴, Fernando Fernandez⁵, ED WPA consortium
¹Schoen Clinic Roseneck, Prien am Chiemsee, Germany, ²Department of Psychiatry and Psychotherapy, LMU University Hospital, Munich, Germany, ³Department of Psychiatry and Psychotherapy, University Hospital of Freiburg, Freiburg, Germany, ⁴Department of Psychiatry, University of Campania “Luigi Vanvitelli”, Naples, Italy, ⁵Department of Clinical Psychology, University Hospital of Bellvitge-IDIBELL and CIBERobn, Barcelona, Spain

Introduction: Chronic and persistent forms of anorexia nervosa, often referred to as persistent, long-lasting, or severe and enduring anorexia nervosa, are widely discussed but lack a standardized definition, hindering comparability across studies and the development of targeted treatment strategies. Methods: A Delphi study with a stable international expert panel was conducted to establish consensus criteria for chronic forms of anorexia nervosa. Three survey rounds were planned using iterative questionnaires. Two rounds have been completed, and the third round will be finalized in May. Approximately 50 experts in the field of eating disorders participated. Results: Preliminary findings indicate emerging consensus on key criteria, particularly illness duration and number of previous treatment attempts. Final consensus, including potential cut-offs, will be determined after completion of the third round and presented at the congress. Conclusions: Developing a consensus-based definition of severe and enduring anorexia nervosa is an important step toward improving diagnostic consistency and supporting future research and treatment development.

P109

Investigation Of Ocular Biomarkers In Eating Disorders
Madeline T. Baker^1,2,3, Amanda Douglass³, Christine T. O. Nguyen³, Andrea Phillipou^1,2
¹Orygen, Parkville, Victoria, Australia, ²Centre for Youth Mental Health, The University of Melbourne, Melbourne, Victoria, Australia, ³Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Victoria, Australia

Introduction: Eating disorders (ED) are increasingly prevalent psychiatric illnesses; yet still associated with unacceptably poor outcomes. Despite this, modern developments in foundational ED research, diagnostic frameworks and treatment methodologies have stagnated. As an accessible window into brain function, ocular biomarkers may provide a unique solution by facilitating objective diagnosis, informing transdiagnostic nosology and elucidating neural mechanisms involved in ED pathogenesis. Consequently, the aim of this study is to explore, identify and evaluate ocular biomarkers in anorexia nervosa (AN) and bulimia nervosa (BN).
Methods: This study intends to recruit 80 participants across 4 groups (n=20/group): (1) AN, (2) BN, (3) AN weight-restored and (4) healthy controls. The experimental protocol will involve 4 key optometric assessments, including optical coherence tomography with confocal multispectral imaging, full-field electroretinography, several saccadic eye movement tasks and a computer-based colour vision test.
Results: It is anticipated that pairwise comparisons (between-groups ANOVAs) will demonstrate unique clinical findings on optometric testing among participants with BN and AN (current and weight restored), compared to healthy controls.
Conclusion: Ocular manifestations in AN and BN may serve as biomarkers of neuropathology to guide objective diagnosis, early intervention, and future research towards biologically informed therapies.

P110

A Six-Month Follow-Up Study Of The Longitudinal Interplay Between Microbiome And Its Metabolite Variations, Psychopathology And Childhood Trauma In The Treatment Of Eating Disorders
Giovanni Castellini, Cristiano Dani, Livio Tarchi, Valdo Ricca
University of Florence, Florence, Italy

Eating disorders (EDs) are associated with a multifactorial etiopathogenesis, involving environmental factors such as childhood trauma, as well as biological factors. Human microbiome has been reported to impact on psychopathology. This study investigated the variations of microbiome and its metabolites (short chain fatty acids SCFAs) before and after six months of enhanced cognitive behavioral therapy. Patients with Anorexia Nervosa (32) and Bulimia Nervosa (28), and 40 controls were assessed at baseline and follow up, in terms of gut microbiota composition and SCFAs, as well as eating disorder psychopathology, and childhood traumatic experiences. A mediation model of early trauma and ED-specific psychopathology linked reduction of microbial diversity to a typical microbiota-derived metabolite such as butyric acid. An overall significant increase of butyric acid was observed after treatment. The proposed model was investigated using bivariate latent change score analysis in a structural equation modeling (SEM) framework. An unidirectional effect of SCFAs concentration on psychopathology variations was outlined by SEM. The psychopathology latent change score was significantly predicted by longitudinal variations of SCFAs. Higher trauma scores predicted reduced variations of SCFAs across time. A possible interpretation for this model might be that childhood trauma represents a risk factor for gut dysbiosis and for a stable modification of mechanisms responsible for SCFAs production.

P111

Insulin-Like Growth Factor-1 And Recovery In Anorexia Nervosa: Evidence From Population-Based And Clinical Cohorts
Cristiano Dani^1,2, Livio Tarchi^1,2, Lorenzo Bonacchi³, Sara Haydar⁴, Emanuele Cassioli⁵, Eleonora Rossi², Francesco De Logu³, Romina Nassini³, Nadia Micali^4,6,7, Valdo Ricca⁵, Giovanni Castellini⁵
¹Department of Neuroscience, Psychology, Drug Research, and Child Health, University of Florence, Florence, Italy, Florence, Italy, ²Careggi University Hospital, Florence, Italy, Florence, Italy, ³Department of Health Sciences, Center for Integrated Translational Research and Knowledge Transfer (INCLINE), University of Florence, Florence, Italy, Florence, Italy, ⁴Center for Eating and Feeding Disorders Research (CEDaR), Mental Health Center Ballerup, Copenhagen University Hospital-Herlev and Gentofte, Copenhagen, Denmark, Copenhagen, Denmark, ⁵Department of Health Sciences, University of Florence, Florence, Italy, Florence, Italy, ⁶Institute of Biological Psychiatry, Mental Health Centre Sct Hans, Copenhagen University Hospital - Amager & Hvidovre, Copenhagen, Denmark, Copenhagen, Denmark, ⁷Great Ormond Street Institute of Child Health, University College London, London, UK, London, United Kingdom

Objectives: Anorexia nervosa (AN) is characterized by growth hormone (GH) resistance and reduced insulin-like growth factor-1 (IGF-1), but longitudinal trajectories during recovery remain insufficiently defined. This study investigated IGF-1 levels across illness stages and examined associations with metabolic parameters and reproductive function. Methods: A cross-sectional population-based analysis was performed in the UK Biobank including 129 women with current AN, 2,380 weight-restored AN, and 2,380 age- and BMI-matched healthy controls (HC), and a longitudinal analysis in an independent clinical cohort of 189 adult women with AN assessed at baseline and after 12 months. IGF-1 group differences were examined using adjusted ANCOVA models, and longitudinal changes and associations with metabolic and reproductive parameters were evaluated using mixed-effects models. Results: IGF-1 levels showed a graded reduction across groups, with the lowest values in current AN and intermediate levels in weight-restored AN compared with HC (p<0.001). In the clinical cohort, IGF-1 increased significantly over 12 months (p=0.003) and was positively associated with insulin, glucose, and FT3, and negatively with GH. Higher IGF-1 levels were independently associated with menstrual function recovery (p<0.001). Conclusions: IGF-1 is associated with metabolic status and reproductive axis reactivation in AN and may represent a clinically informative biomarker of illness severity and treatment response.

P112

Longitudinal Analysis Of Decision-Making Deficits In Binge-Eating Disorders Using Drift Diffusion Modeling
Glen Forester^1,2, Brianne N. Richson^1,2, Erin E. Reilly³, Lisa M. Anderson⁴, Stephen A. Wonderlich^1,2, Lauren M. Schaefer^1,2
¹Sanford Research, Fargo, ND, United States, ²University of North Dakota, Grand Forks, ND, United States, ³University of California San Francisco, San Francisco, CA, United States, ⁴University of Minnesota, Minneapolis, MN, United States

Individuals with binge-type eating disorders (binge-EDs) repeatedly engage in binge eating despite negative consequences, suggesting altered decision-making. The cognitive mechanisms underlying these alterations remain poorly understood. In this longitudinal study, we applied the drift diffusion model (DDM) to examine how decision-making processes relate to binge-eating frequency over time. Ninety-five adults with binge-EDs (69% binge-eating disorder) completed a probabilistic reward task at baseline and 3-months, with binge-eating frequency assessed concurrently and at 6-months. Slower evidence accumulation (lower drift rate) consistently predicted greater binge-eating frequency cross-sectionally (baseline p<.001; 3-month p=.018) and prospectively (6-month p<.001), highlighting impaired integration of decision-relevant information as a possible mechanism maintaining binge eating. Lower decision threshold, indicating less cautious decision-making, was cross-sectionally associated with greater binge-eating frequency (baseline p<.001) but did not predict symptoms over time (p’s>.552). Reward sensitivity (start bias) showed no significant relationship with binge-eating frequency (p’s>.357). These findings suggest that specific deficits in core decision-making processes contribute to binge-eating persistence, suggesting novel intervention targets. Additionally, our study demonstrates the utility of the DDM as a computational framework for unifying behavioral data within the binge-ED literature.

P113

Exploration Of Neural Substrates Underlying Emotion Regulation In Youth With Overweight/Obesity And Loss Of Control Eating
Andrea B. Goldschmidt¹, Jared Saletin², Elissa Jelalian², Erin Stalvey¹, Danielle Chapa¹, Daniel P. Dickstein³
¹University of Pittsburgh School of Medicine, Pittsburgh, PA, United States, ²Warren Alpert School of Medicine of Brown University, Providence, RI, United States, ³McLean Hospital/Harvard Medical School, Boston, MA, United States

Introduction: Loss of control (LOC) eating and obesity predict poor health outcomes in childhood and may be related to underlying deficiencies in self-regulatory and affective processes. Little is known about the neural signature of these putative mechanisms. Methods: We evaluated neural activation patterns of 53 youth (10-17y; 52.8% female) with LOC eating and overweight/obesity (OW-LOC; n=14), relative to their peers with (OW-CON; n=25) and without overweight/obesity (NW-CON; n=14) during cognitive reappraisal, an adaptive form of emotion regulation. Youth underwent fMRI while viewing aversive or neutral images, with instructions to either maintain their emotional state or regulate their emotions using cognitive reappraisal strategies. Results: During cognitive reappraisal, OW-LOC showed alterations in BOLD responses in the right hippocampus (involved in memory and negative emotion processing) relative to OW-CON and NW-CON, while OW-CON showed alterations in the right middle temporal gyrus (involved in emotion regulation) and left middle frontal gyrus (involved in cognitive control) relative to NW-CON. Activation in these regions correlated with self- and parent-report measures of emotion regulation. Conclusions: Neural differences in self-regulation and affective processing may underlie eating- and weight-related concerns, although directionality is unclear. Findings could support targeted mechanistic preventive and early intervention programs for improving pediatric health.

P114

The Association Of Substructural Cerebellar Volume And Clinical Outcomes In The Long-Term Treatment Of Patients With Anorexia Nervosa
Lisa Guth¹, Lisa-Katrin Kaufmann^1,2, Tugce Aras ¹, Joanna Gawinecka³, Gergely Karsai³, Gabriella F. Milos¹
¹ Department of Consultation-Liaison-Psychiatry and Psychosomatic Medicine, University Hospital Zurich, Zurich, Switzerland, ²University of Zurich, Department of Psychology, Zurich, Switzerland, ³Institute for Clinical Chemistry, University Hospital Zurich, Zurich , Switzerland

Introduction: The reconceptualization of Anorexia nervosa (AN) as metabo-psychiatric disorder strengthen the investigation of neurobiological predictors of treatment success. Hereby, substructural cerebellar volume (SCV) reduction is considered as a predictive factor, while cerebellar concentration of leptin receptors warrants further investigation of its association with leptin. Up to date this association has not yet been studied in SCV. Methods: T1-weighted MRI scans of AN patients, recruited at the Center for Eating Disorders, University Hospital Zurich, and retrospectively grouped at follow-up (FU) in weight-maintained AN (wm-AN) and weight-relapsed AN (wr-AN), are subsegmented by suit-toolbox (SPM). Using linear mixed models, changes in SCV are compared in course of inpatient treatment between wm-AN and wr-AN and their associations with serum leptin, BMI (kg/m²), and psychiatric symptoms (EDE-Q, BDI) examined by multiple linear regression. General linear models compared SCV between groups at FU. Results: It is expected that wm-AN show stronger structural restoration of SCV from admission to discharge compared to wr-AN, while being positively associated with leptin and BMI and negatively associated with psychiatric symptoms. SCV is expected to be stronger reduced in wr-AN compared to wm-AN at FU. Conclusions: Reduced SCV may contribute to the core symptoms and thus the maintenance of AN, while its associations with leptin could extend findings of leptin for prognosis.

P115

Off-Label Metreleptin Treatment In A Female Underweight Adult Inpatient With Severe Anorexia Nervosa And A Pronounced Physical Activity: A Case Report.
Linus Imken¹, Marc Leiteritz², Janine Greibel², Wally Wuensch-Leiteritz², Andreas Leiteritz², Verena Haas¹
¹Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Child and Adolescent Psychiatry, Psychosomatic Medicine and Psychotherapy, Berlin, Germany, ²Klinik Lueneburger Heide, Bad Bevensen, Germany

Background: case reports suggest short-term metreleptin treatment (MT) may improve core anorexia nervosa (AN) symptoms, i.e. food-related thoughts, fear of weight gain, feeling fat, depressive symptoms, excessive physical activity (PA) and sleep quality. Methods: off-label MT in a female inpatient with AN (BMI, 15.9 kg/m², 18 years-old), major depressive disorder, and weight stagnation linked to excessive PA (measured via step count tracker). Visual Analogue Scales were used daily during MT to assess subjective AN-related behaviors, cognitions and emotions; and exhaustion, fatigue, sleep quality. Eating disorder psychopathology (EDI-2), psychological impairment (SCL-90-R), depression (BDI-II) and obsessive-compulsive symptoms (OCI-R) were assessed pre- and 8-week post-MT-end. Results: during MT (6–12 mg/day, 18 days) starting on day 150 of inpatient treatment, exhaustion (7→0), fatigue (5→1), sleep quality (4→0) and mood (8→5) improved, PA remained unchanged (~50,000 steps/day). Over 8 weeks, food-related thoughts, fear of weight gain, feeling fat and inner tensions remained high. EDI-2 (397→376), SCL-90-R (65→63), and OCI-R (100→96) showed minor reductions and remained elevated, while BDI-II decreased (43→28). Treatment was well tolerated, only slight headache and brief injection site erythema occurred. Weight remained stable (~46.5 kg). Conclusion: at unchanged PA, energy levels and mood improved during MT. Randomized controlled trials are needed.

P116

Associations Between Ovarian Hormones And Binge Eating Attitudes/Behaviors Across The Perinatal Period
Riley J. Jouppi¹, Colin E. Vize¹, Kelly L. Klump², Michele D. Levine^1,3
¹University of Pittsburgh, Pittsburgh, PA, United States, ²Michigan State University, East Lansing, MI, United States, ³University of Pittsburgh School of Medicine, Pittsburgh, PA, United States

Binge eating attitudes/behaviors (BEs) during the perinatal period are poorly understood despite their high prevalence. Interactions between estradiol and progesterone (E×P) predict changes in BEs within non-perinatal individuals across the menstrual cycle. This study tested within- and between-person E and P, and within-person E×P, effects on BEs across the perinatal period. Participants in a perinatal lifestyle intervention (N=296) completed fasted blood draws and the Eating Disorder Examination-Questionnaire in early and late pregnancy and at 6- and 12-months postpartum. Five BEs items were z-scored and averaged to create a BEs composite score. A multilevel model decomposed E and P into within- and between-person components, included time as a moderator of within-person E×P, and adjusted for randomization status. There were no significant effects of within-person E or P, or between-person E or P, on BEs in early pregnancy (all p≥.46). The effect of within-person E×P on BEs was marginal in early pregnancy (b=-0.26, p=.07). Compared to early pregnancy, within-person ExP effects did not significantly differ in late pregnancy (b=0.41,p=.13) but became significantly stronger at 6- (b=0.55,p=.04) and 12- (b=0.56,p=.01) months postpartum. Within individuals, BEs were highest when both E and P were high; however, this association emerged only during postpartum, not during pregnancy. Next steps involve clarifying directionality and examining dynamic coupling among variables.

P117

Longitudinal Predictors Of Healthcare Utilization In A Nationally Representative Sample Of U.S. Veterans With And Without Eating Disorders
Kazi Md Farhad Mahmud Mahmud¹, Marianna LeVa Thomeczek², Sonakshi Negi², Kelsie Terese Forbush¹²
¹Center for the Advancement of Research on Eating Behaviors (CARE), University of Kansas, Lawrence, KS, United States, ²Department of Psychology, University of Kansas, Lawrence, KS, United States

Introduction: Eating disorders (EDs) are associated with significant healthcare burden, yet their role in healthcare utilization among U.S. veterans remains understudied. Veterans may be at elevated risk for EDs due to military-related body composition pressures. This study examined healthcare utilization and predictors of use over time in a nationally representative sample of post-9/11 veterans. Methods: Data were drawn from a DoD-funded longitudinal study of U.S. veterans (N=917) with assessments at baseline, 3 months, and 6 months. Outcomes included general, outpatient mental health, and emergency service use. Analyses examined whether utilization differed by ED status across demographic groups. Longitudinal predictors are being examined using the Generalized Bivariate Bernoulli Model. Results: At baseline, general healthcare use did not differ significantly by ED status (84.1% vs 78.1%, p=0.090). However, veterans with EDs were more likely to use outpatient mental health services (32.9% vs 21.8%, p=0.003) and emergency services (25.2% vs 13.6%, p<0.001). Only 32.9% of veterans with EDs received mental health care. These findings will be extended through longitudinal analyses examining predictors for healthcare utilization over time. Conclusions: EDs appear to be associated with increased mental-health and emergency-service use, but not general care. Despite this, many affected veterans do not receive care, suggesting a treatment gap and need for improved screening and access

P118

Processing Of Body Stimuli In Adolescents With Anorexia Aervosa &Ndash; A Behavioral And Neurophysiological Investigation
Anca Sfärlea, Christina Buhl, Linda Lukas, Gerd Schulte-Körne
Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, LMU University Hospital, Munich, Germany

Introduction. Body image disturbance is a core symptom of anorexia nervosa (AN) and may be associated not only with altered perception of one’s own body, but also of others’ bodies. The present study investigates the perception and processing of body stimuli in adolescents with AN on behavioral and neurophysiological levels. Methods. Adolescent girls with AN (n=33; 12–18 years) were compared to girls without mental disorders (n=41). Participants categorized standardized photographs of female bodies with varying weights as well as neutral objects (as control stimuli) while event-related potentials (ERPs) were recorded and subsequently rated the stimuli on valence and arousal. Results. On the behavioral level, adolescents with AN evaluated female bodies more negatively (except extremely underweight bodies) and overestimated body weight more frequently than adolescents without mental disorders. On the neurophysiological level, adolescents with AN exhibited lower late positive potential (LPP) amplitudes in response to all body categories but not to control stimuli. In both groups, extremely underweight bodies elicited highest amplitudes, indicating that they were perceived as most salient. Conclusions. Behavioral findings support the hypotheses, whereas neurophysiological results were partly unexpected. The results contribute to a better understanding of altered perception and processing of bodies in adolescents with AN and will be discussed in relation to body image disturbance.

P119

Inhibitory Processing Alterations In Adolescents With Binge Eating Disorder And Emotional Eating: A Preliminary Analysis
Esther Via^1,2, Laura Astiasuainzarra¹, Mia Ruth³, Mar Fandiño^4,5, Teresa Logroño², Ares Sentenach², Belen Gil⁶, Silvia Marin², Marina LLobet², Anna Aranda², Marta Ramon^1,2
¹, Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona, Spain, ²Department of Child and Adolescent Mental Health, Hospital Sant Joan de Déu, Barcelona, Spain, ³Universitat de Barcelona, Barcelona, Spain, ⁴Hospital del Mar Research Institute, Barcelona, Spain, ⁵Pompeu Fabra University, Barcelona, Spain, ⁶Institut d’investigació en Atenció Primària de Salut Jordi Gol, Barcelona, Spain

Introduction: Binge eating disorder (BED) and emotional eating (EE) are associated with emotion regulation difficulties, but evidence on their neural mechanisms remains limited. Methods: Adolescents aged 12–18 years with obesity and BED, EE or no eating-related pathology (control subjects, CS) were recruited in an ongoing study on reward and inhibitory-control circuits (currently n=56). This preliminary fMRI analysis examined Stop correct > Go correct in a subsample (BED=4, EE=5, CS=5). A three-group full factorial model included age and sex as covariates. Maps were thresholded at voxel FDR<0.5. Results: Groups did not differ in age, body mass index percentile or sex distribution. Go accuracy did not differ, whereas Stop accuracy differed by group (F(2,11)=5.228, p=.025, η²=.487), being higher in BED than EE (p=.021). In fMRI, BED/EE showed lower activation than CS in a left premotor/precentral cluster (BA6, k=81, Z=5.74, PFDR=.002), while BED showed greater activation than EE/CS in left medial anterior prefrontal/frontopolar cortex (BA10, k=55, Z=5.16, PFDR =.049). Conclusion: Findings suggest distinct inhibitory-control alterations in BED and EE, which may reflect shared motor inhibitory-control disruption alongside a BED-specific compensatory frontopolar response. Results require validation in the in the forthcoming full sample.

P120

Longitudinal And Bidirectional Associations Between Eating Disorder Psychopathology And Emotion Regulation: A Multilevel Meta-Analysis And Systematic Review
Ying Qing Wong¹, EllenEllen McEwana¹, Trevor Steward¹, Matthew Fuller-Tyszkiewicz², Isabel Krug¹
¹School of Psychological Sciences, The University of Melbourne, Melbourne, , ²School of Psychology, Deakin University, Melbourne,

Introduction: Emotion dysregulation is a risk factor for EDs. However, previous reviews have primarily focused on the cross-sectional association between emotion regulation (ER) and ED psychopathology. This meta-analysis and systematic review synthesised longitudinal studies examining the association between ER and ED psychopathology over time. Methods: A literature search following PRISMA guidelines identified 63 studies (N = 26,906) from PsycINFO, MEDLINE, Embase and Web of Science (all years until 1^st December 2025), comprising clinical and community samples. Multilevel random-effects models were conducted for 26 studies with extractable effect sizes. Results: Global ER difficulties, limited access to strategies, lack of emotional awareness and clarity, and difficulties engaging in goal-directed behaviour were associated with subsequent increased ED psychopathology (r = 0.04-0.06). ED psychopathology was associated with later impulse control difficulties and non-acceptance of emotions (r = 0.06-0.09). Rumination was bidirectionally associated with ED psychopathology (r = 0.07-0.15). A systematic review of the remaining 37 studies supported the meta-analysis and identified within-person effects. Conclusions: Our review found modest longitudinal associations between ER and ED psychopathology, with temporal direction differing across ER dimensions. Future research is needed to examine the viability of ER, especially rumination, as an ED intervention target.

P121

Self-Reported Eating Disorder Risk Behaviours As Predictors Of Co-Occurring And Later Psychiatric Outcomes: A Danish Follow-Up Study Over 24 Years
Heidi Amalie Rosendahl Jensen¹, Ola Ekholm¹, Nadia Micali², Daiva Daukantaité³, Michael Davidsen¹, Lau Caspar Thygesen¹
¹National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark, ²Center for Eating and Feeding Disorders Research, Mental Health Center Ballerup, Copenhagen University Hospital – Mental Health Services CPH, Ballerup, Denmark, ³Department of Psychology, Lund University, Lund, Sweden

Background: Eating disorders are strongly associated with psychiatric comorbidities. Therefore, validated screening instruments to detect eating disorder risk behaviours may be expanded to identify vulnerable individuals at increased risk of other psychiatric outcomes than eating disorders alone. Using such instruments may thus facilitate early identification of at-risk individuals and prevent the development of severe illness. The aim of this study was to examine the association between eating disorder risk behaviours and various psychiatric outcomes in the general adult population in Denmark. Methods: Information on eating disorder risk behaviours was derived from a validated screening instrument, Risk Behaviour for Eating Disorder 8-items (RiBED-8), and collected by self-administered questionnaires among respondents aged ≥16 years in the Danish Health and Morbidity Survey 2000 and 2005 (n=9,376). Respondents were followed in administrative registers by individual-level linkage until end 2024. Cox proportional hazard models were used to examine the association between eating disorder risk behaviours and mental disorders (ICD-10 codes F00-F99), antidepressant use (ATC codes N06AA-B, N06AF-G, N06AX), and visits to psychologist/psychiatrist (speciality codes 630000-630209/240105-240336). Results: At the time of submission, analyses are still ongoing. Thus, results are currently pending and will be presented at the conference. Conclusions: To be presented at the conference.

P122

Transdiagnostic Associations Of Autistic Traits In Eating Disorders: Evidence From The Treat Registry
Marion Roberts¹, Ashleigh Blake², Christopher Thornton³, Colleen Alford², Christopher Basten⁴, Sue Byrne⁵, Mandy Goldstein⁶, Phillipa Hay², Gabriella Heruc², Deborah Mitchison⁷
¹University of Auckland, Auckland, New Zealand, ²Western Sydney Universtiy, Sydney, Australia, ³The Redleaf Practice, Sydney, Australia, ⁴Basten & Associates, Sydney, Australia, ⁵University of Western Australia, Perth, Australia, ⁶everyBody Psychology & Wellbeing, Sydney, Australia, ⁷University of Technology Sydney, Sydney, Australia

Introduction: High rates of autism have been identified in anorexia nervosa, but less is known about autistic traits across the full eating disorder (ED) diagnostic spectrum. Method: Cross-sectional analysis of baseline data from a prospective, multi-site clinical quality registry (TrEAT) was conducted, pooling adult ED outpatient data across Australia and New Zealand. Participants completed demographic items and measures of ED symptoms, autistic traits, psychological distress, intuitive eating, and ED-related functional impairment. Data collection is ongoing. Results: Preliminary analyses included 240 treatment seekers (90.8% female; M BMI = 25.10, SD = 8.64). The proportion of those with elevated autistic traits did not differ across ED diagnoses. Autistic traits were not associated with global ED severity (EDE-Q) or ED-related functional impairment (CIA). However, elevated autistic traits were associated with greater eating concerns, psychological distress, depression, anxiety, stress, and poorer intuitive eating, independent of ED symptoms. Conclusions: Autistic traits are transdiagnostically associated with increased secondary psychopathology among ED outpatients. These findings highlight the importance of assessing autistic traits in routine care, and support the development of tailored interventions across diagnoses to target co-occurring distress.

P123

Autism Spectrum Disorder, Attention-Deficit/Hyperactivity Disorder,Tic Disorder And Obsessive-Compulsive Disorder In Individuals With Eating Disorders And Their Siblings: A Register-Based Nationwide Finnish Cohort Study
Emma Saure¹, Pyry N. Sipilä², Susanna Hinkka-Yli-Salomäki³, Andre Sourander^{3, 4}, Elina Santti⁵, Anu Raevuori^{1, 5}
¹Clinicum, Department of Psychiatry, University of Helsinki, Helsinki, Finland, ²Department of Public Health, University of Helsinki, Helsinki, Finland, ³Research Centre for Child Psychiatry, INVEST Flagship, University of Turku, Turku, Finland, ⁴Department of Child Psychiatry, Turku University Hospital, Turku, Finland, ⁵Department of Psychiatry, Division of Adolescent Psychiatry, Helsinki University Hospital and University of Helsinki, Helsinki, Finland

Objective: Neurodevelopmental conditions frequently co-occur with eating disorders (EDs) and genetic studies support a shared etiology between them. We aimed to investigate the occurrence of attention-deficit/hyperactivity disorder (ADHD), ASD, tic disorder (TD), and OCD in individuals with EDs and in their full and half siblings. Method: Study population comprised all individuals born in Finland between 1991-2001 with a recorded diagnosis of following ICD-10 EDs (N=4240 individuals): anorexia nervosa (AN, F50.0/F50.1), bulimia nervosa (BN, F50.2/F50.3), and other/unspecified EDs (F50.8/F50.9). We also included population controls (N=16494) without ED diagnoses and full and half siblings of ED and control participants (N=36301). Conditional logistic regression was applied in analysis. Results: Individuals with AN had 6-fold odds of ASD, 3-fold odds of ADHD, and 10-fold odds of OCD compared to population controls. Individuals with other/unspecified EDs had 8.5-fold odds of ASD, 2.5-fold odds of ADHD, 4.5-fold odds of TD, and 7.5-fold odds of OCD. Compared to full siblings of population controls, full siblings of individuals with AN had 2-3-fold odds of ASD and OCD; and full siblings of individuals with other/unspecified EDs had 2-3-fold odds of ASD, ADHD, TD, and OCD. Conclusions: Individuals with EDs have a high occurrence of neurodevelopmental conditions, also extending to their full siblings. The findings characterize the comorbidity and familial aggregation of these conditions.

P124

Eating Disorders In A Canadian Master Observational Trial Of Multiple Mental Health Conditions
Sarah Smith^1,2, Melissa Kimber³, Ryan Aloysius⁴, Sadanee Pathiranawas⁵, Gary Goldfiend⁶, Amelia Austin⁵, Gina Dimitropoulos⁵, Paul Arnold⁵, Cheryl Webb ⁷, Suneeta Monga^1,2, Jennifer Couturier^3,7
¹Hospital for Sick Children, Toronto, ON, Canada, ²University of Toronto, Toronto, ON, Canada, ³McMaster University, Hamilton, ON, Canada, ⁴Centre for Addictions and Mental Health, Toronto, ON, Canada, ⁵University of Calgary, Calgary, AB, Canada, ⁶Children's Hospital of Eastern Ontario, Ottawa, ON, Canada, ⁷McMaster Children's Hospital , Hamilton, ON, Canada

Introduction: Little is known about the prevalence of eating disorders (EDs) among youth seeking mental health care. Using data from the initial year of the CALM Master Observational Trial (MOT), we will characterize the prevalence and clinical features of help-seeking youth with eating disorders. Methods: CALM is prospectively enrolling youth with multiple mental health conditions (MMHC) aged 11-24 at six clinical sites across Canada. Harmonized data collection includes youth and caregiver-report questionnaires, clinical interviews, cognitive tasks, neuroimaging, and biological samples over 42 months. MH diagnoses are indexed using the Diagnostic Assessment for the Health Spectrum (DASH) which captures anorexia and bulimia nervosa. Results: We have enrolled 456 participants since March 2025. At baseline, 19.3% have screened positive for an ED (n=88) ranging in age from 12 to 24 years. Demographically, 68.5% identify as female, 11.9% as male, 19.6% as diverse gender identities; and 30.1% as non-white. Common co-occurring MH conditions include mood disorders (81.8%), anxiety disorders (86.4%), substance use (34.1%), ADHD (48.9%), self-harm (47.7%), and suicidal ideation or behaviour (43.2%). Discussion: EDs appear common among help-seeking youth with MMHC in CALMs specialist and generalist MH care settings. Follow-up over study duration will clarify symptom and disorder trajectories. CALM’s MOT design offers key infrastructure to undertake an eating clinical trial.

P125

Inhibitory Control, Reward Sensitivity And Punishment Sensitivity As Transdiagnostic Risk Factors For Addictive Behaviors In Adolescents
Eva Van Malderen¹, Jakke Coenye¹, Lien Goossens¹, Sandra Verbeken¹, Eva Kemps², Laurence Claes^{3, 4}
¹Faculty of Psychology and Educational Sciences, Department of Developmental, Personality and Social Psychology, Ghent University, Belgium , Ghent, Belgium, ²Psychology, College of Education, Psychology and Social Work, Flinders University, Adelaide, Australia, Adelaide, Australia, ³Faculty of Psychology and Educational Sciences, KU Leuven, Belgium, Leuven, Belgium, ⁴Faculty of Medicine and Health Sciences, University of Antwerp, Belgium, Antwerp, Belgium

Introduction: Addictive behaviors are commonly reported by adolescents, with poor self-regulation as a possible risk factor. Existing research has predominantly been cross-sectional, frequently conducted in adult samples and largely focused on one addictive behavior or one self-regulatory process. This longitudinal study therefore examined several self-regulatory processes (inhibitory control, reward and punishment sensitivity) as transdiagnostic risk factors for a range of addictive behaviors (binge eating, tobacco-, cannabis-, and alcohol use, gaming, gambling and pathological buying) in adolescents across a one-year interval. Methods: A community sample of 116 adolescents (67.2% female; M_age = 15.22 years, SD_age = .64 at Time 1) reported on self-regulation and addictive behaviors at both time-points. Multiple regression analyses assessed main and interaction effects of self-regulation (Time 1) on addictive behaviors (Time 2). Results: Higher reward sensitivity predicted increased pathological buying one year later. Low inhibitory control combined with high punishment sensitivity predicted more binge eating one year later. Girls were at greater risk of binge eating, whereas boys were more prone to gambling. Most addictive behaviors showed substantial stability over time. Conclusions: High reward sensitivity emerged as an important risk factor for pathological buying and poor inhibitory control paired with high punishment sensitivity increased the risk for binge eating.

P126

Longitudinal Association Between Body Dissatisfaction In Early Adolescence And Multiple Risk Behaviours In Late Adolescence: Evidence From The Uk Millennium Cohort Study
Ariana Kular¹, Madelaine D Kellock¹, Ilaria Costantini¹, Yanshang Wang¹, Georgina Krebs², Daniel Rautio³, Ulrike Schmidt ⁴, Glyn Lewis¹, Francesca Solmi¹
¹Division of Psychiatry, University College London, London, United Kingdom, ²Division of Psychiatry, Imperial College London, London, United Kingdom, ³Karolinska Institutet , Stockholm, Sweden, ⁴Institute of Psychiatry, Kings College London, London, United Kingdom

Introduction: Despite putative associations, longitudinal evidence on associations between body dissatisfaction and risk behaviours in adolescence is limited. We investigated whether body dissatisfaction at age 14 was associated with risk behaviours at age 17. Methods: Using data from the UK Millennium Cohort Study, we investigated whether appearance dissatisfaction, perceived weight status, and weight intention at age 14 were associated with a sum score of and individual risk behaviours (e.g. drug use, gambling, unsafe sex) using univariable and multivariable linear and logistic regressions, respectively. Analyses presented here are based on a complete case sample, while final analyses will impute missing confounder and outcome data. Results: The analytical sample included 3,407 participants (56% female, 17.4% ethnic minority). Only perceiving oneself as very overweight (mean difference[MD]: 0.74, 95%CI 0.26 to 1.22) and wanting to lose (MD: 0.53, 95%CI: 0.37 to 0.69) or gain weight (MD: 0.58, 95%CI: 0.25 to 0.90) were associated with greater engagement in multiple risk behaviours, with weak evidence of an association for appearance dissatisfaction (coefficient: 0.03, 95%CI: −0.02 to 0.07). Patterns were similar across individual behaviours. Conclusions: Body dissatisfaction is a risk factor for engagement in multiple risk behaviours; interventions to reduce it or prevent it could have public health benefits.

P127

Research Update: A Systematic Review Of The Relationship Between Eating Disorder Symptoms And Parental Socioeconomic Status (Ses) Among Adolescents
Lea Steinstad¹, Alice Schittek¹, Marcelo R Cardona Cabrera¹, Nadia Micali^1,2, Nora Trompeter²
¹Center for Eating and feeding Disorders Research, Mental Health Center Ballerup, Copenhagen University Hospital – Herlev and Gentofte, Copenhagen, Denmark, ²Great Ormond Street Institute of Child Health, UCL, London, United Kingdom

Introduction: Eating disorders (EDs) have long been viewed as disorders affecting higher socioeconomic groups, yet recent evidence shows they occur across all backgrounds. This systematic review and meta-analysis evaluated the relationship between parental socioeconomic status (SES) and ED symptoms in adolescents in the general population and assessed how SES is operationalized in community-based studies. Methods: A PRISMA search was carried out across six databases to identify quantitative studies from Western countries. The search produced 56,653 records, and 51 articles met inclusion criteria. Results: Parental education was the most used SES measure across the included studies (>50). The meta-analysis revealed a significantly lower likelihood of ED symptoms in adolescents of parents with higher educational backgrounds (OR = 0.83, 95% CI: 0.72 – 0.95, p = .007). Household income was generally negatively associated with ED symptoms in adolescents. Findings related to SES indexes and other SES proxies were inconsistent. Conclusions: Adolescents from lower education and lower income households are more likely to present with ED symptoms. Findings highlight the influence of socioeconomic disadvantage on ED presentations, underscoring the need for targeted prevention and intervention efforts that address socioeconomic disparities. Future research should incorporate multidimensional SES measures to better capture the complex nature of socioeconomic disadvantage.

P128

Prevalence And Correlates Of Parent-Reported Avoidant/Restrictive Food Intake Disorder Symptoms In A United States Nationally Representative Sample Of Children And Adolescents
Ruth S. Weissman¹, Jennifer Rose¹, Andy G. Sampedro ¹, Gabrielle Sorin¹, Caitlin Martin-Wagar²
¹Wesleyan University, Middletown, CT, United States, ²University of Montana, Billings, MT, United States

Objectives. The growing literature describing the demographic and clinical correlates of Avoidant/Restrictive Food Intake Disorder (ARFID) has been based largely on clinical pediatric samples. With eating disorders often going undetected, our study aims to describe the prevalence and correlates of caregiver-reported ARFID symptoms in youth ages 6 to 17 years. Method. Extracting 2024 data from the National Survey of Children�s Health from participants with valid data on ARFID symptoms, we calculated design adjusted prevalence of ARFID symptoms overall, and by sex and age. An upset plot was created to illustrate overlap among ARFID symptoms. Results. Overall, 24.5% of youths reported at least one symptom. Extremely picky eating was most common (20.8%) and in 14% of youths was the only symptom. Low interest in food was reported by 10.2% and was the sole ARFID symptom in 3.4% of the sample. Fear-based restrictive eating was least common (0.8%) and occurred by itself in only 0.1% of youths. Only 0.3% of youths had all three symptoms. ARFID symptoms frequencies varied by sex and age. Discussion. Our study represents an important step toward documenting (with national data rather than clinical samples) the extent of ARFID as a concern among US youth. Similar efforts in other countries are needed to build a global evidence base about the burdens of suffering attributable to ARFID among pediatric populations.

P129

Beyond Risk: Genetic Underpinnings Of Resilience In Anorexia Nervosa
Sara Haydar¹, Mohamed Abdulkadir², Helena Davies^1,3, Joeri Meijsen^1,3, Bilal Ashraf¹, Liselotte Vogdrup Petersen², Cynthia Bulik^4,5,6, Thomas Werge³, PGC-ED Working Group , Nadia Micali¹
¹Center of Eating and feeding Disorder Research, Mental Health Centre Ballerup, Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark, ²The National Centre for Register-based Research, Department of Public Health, Aarhus University, Aarhus, Denmark, ³Institute of Biological Psychiatry, Mental Health Center Sct. Hans, Copenhagen University Hospital - Amager and Hvidovre Hospital, Copenhagen, Denmark, ⁴Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ⁵Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ⁶Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden

Introduction: Genetic resilience to anorexia nervosa (AN), defined as remaining unaffected despite a high genetic risk, is poorly understood. This study is the first to investigate the genetic factors underlying AN resilience. Methods: We calculated the AN polygenic risk score in UK Biobank and iPSYCH-ANGI-DK (N~537,962) using the latest genome-wide association study (GWAS) of AN. Among individuals at high genetic risk (top 10%), those without AN were defined as resilient and those with AN as non‑resilient. A GWAS of AN resilience was conducted in each cohort using individuals of European ancestry and subsequently meta-analyzed. We then derived an AN polygenic resilience score (PResS) from variants independent of AN risk (as identified in the aforementioned GWAS of AN). Results: In total across cohorts, we identified 52,748 resilient and 1,329 non-resilient individuals. AN PResS was higher in individuals without AN than in those with AN (β=0.40-0.51, SE=0.02; P<1 × 10^-80), with the strongest effect in resilient individuals. No genome-wide significant loci were identified in the resilience GWAS meta-analysis. The top 10 independent variants suggestively associated had larger effect sizes for resilience than for AN risk. Conclusions: Our data suggest partially distinct genetic factors underlying resilience, independent from AN risk. Further validation in independent cohorts is needed to confirm these findings and clarify biological pathways.

P130

Baseline Estradiol And Compulsive Exercise Predict Changes In Handgrip Strength In Hypoestrogenic Individuals With Restrictive Eating Disorders
Sarah Naticchia^1,3,4,6, Rohith Korukonda^1,4, Luke Dysart^1,4, Siddarth Seenivasa^1,4, Meghan Slattery^3,6, Jennifer J. Thomas^1,2,3,5, Poornima Kumar^5,8, Elizabeth A. Lawson^3,6,7, Madhusmita Misra⁹, Megan Rosa-Caldwell¹⁰, Kamryn T. Eddy^1,2,3,5, Lauren Breithaupt-Langston^1,2,3,4,5
¹Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States, ²Eating Disorders Clinical and Research Program, Massachusetts General Hospital,, Boston, MA, United States, ³Mass General Brigham Multidisciplinary Eating Disorders Research Collaborative, Mass General Brigham, Boston, MA, United States, ⁴Psychiatry Neuroimaging Laboratory, Department of Psychiatry, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States, ⁵Department of Psychiatry, Harvard Medical School, Boston, MA, United States, ⁶Neuroendocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, ⁷Department of Medicine, Harvard Medical School, Boston, MA, United States, ⁸Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, MA, United States, ⁹Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, VA, United States, ¹⁰Department of Human Health, Performance, and Recreation, University of Arkansas, Fayetteville, AR, United States

Background: Restrictive eating disorders (R-EDs) are often accompanied by oligo- or amenorrhea, reflecting hypoestrogenemia that may impair muscle function. We hypothesized that increases in estradiol over 8 weeks would predict handgrip strength improvements in R-EDs. Methods: Handgrip strength was measured at baseline and 8 weeks in 30 hypoestrogenic individuals with R-EDs from a larger RCT of physiologic estrogen vs. placebo. Linear regression tested whether estradiol change predicted grip change, adjusting for baseline estradiol and grip. Exploratory models examined whether reductions in compulsive exercise test (CET) scores were associated with grip change. Results: Estradiol change did not predict grip change (p=0.46), possibly reflecting limited power or insufficient time for hormonal effects on strength. Higher baseline estradiol predicted smaller strength gains (β=−0.040, p=0.04), indicating greater improvement among more hypoestrogenic individuals, independent of baseline strength. Among ED psychopathology measures, only CET improvements predicted grip gains after adjusting for baseline grip (β=0.53, p=0.04); other measures did not survive adjustment. Conclusions: Short-term estradiol change did not drive strength gains. Baseline hormonal status and reductions in compulsive exercise were independently associated with greater grip gains, suggesting that targeting compulsive exercise may support physical recovery in R-EDs. Replication in larger samples is warranted.

P131

Disordered Eating, Eating Disorders And Food Addiction In Mid To Later Life: A Systematic Review
Sara Banks¹, Jamie Ross¹, Lucy Serpell², Claudia Cooper¹
¹Queen Mary University London, London, United Kingdom, ²University College London, London, United Kingdom

Introduction
By 2030, 1 in 6 people will be aged 60 or over. The prevalence, presentation and impact of disordered eating in older adults is poorly understood, concerning given comorbidities, health inequalities and barriers to care in later life. This is the first systematic review of disordered eating, eating disorders and food addiction in mid to later life, undertaken to inform research and practice. Methods
Following PRISMA guidelines and PROSPERO registration, CINAHL, MEDLINE, PsycINFO and Scopus were searched (2000–2025) using keywords on age, eating disorders and food addiction. Quantitative studies reporting prevalence, incidence, onset, interventions and outcomes were included, alongside qualitative studies on lived experience. Results
Fifty-five studies met inclusion criteria, almost all quantitative. Prevalence and correlates are reported across population, clinical, health, social care and community samples, with findings interpreted in relation to health, social and cultural factors. Conclusions
Findings indicate associations with emotional distress, long-term conditions, socio-economic adversity and relational difficulties. Though prevalence appears to be lower than in younger adults, disordered eating persists into later life. Evidence is limited and heterogeneous, with little longitudinal or experiential research and underrepresents diverse older populations. Further research is needed for age-appropriate screening, diagnosis and interventions.

P132

Current Practise Used To Identify And Manage Binge Eating Disorder And Bulimia Nervosa In Primary Care In The Uk: A National Survey
Stella Kozmér^1,2, Jane R. Smith¹, Alex Burns^1,3, Natalia S. Lawrence⁴, Samantha B. van Beurden¹
¹University of Exeter Medical School, University of Exeter, Exeter, UK, Exeter, United Kingdom, ²Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom, ³Three Spires Medical Practice, Truro, Cornwall, United Kingdom, Truro, United Kingdom, ⁴Department of Psychology, University of Exeter, Exeter, UK, Exeter, United Kingdom

Background: Our previous review highlighted that limited knowledge and understanding of Binge Eating Disorder (BED) and Bulimia Nervosa (BN) amongst healthcare professionals (HCPs) working in primary care may negatively impact their identification and management. Whilst UK guidelines provide some guidance, it is currently unknown what, if anything, is actively implemented in practice. Aim: To map current practices used in primary care in the UK to identify and manage BED/BN. Methods: An online mixed-method survey of primary care HCPs and individuals with lived experience (LE) of BED/BN aged 16+ years using convenience and purposive sampling. Data was analysed using descriptive statistics and thematic analysis. Results: Of 598 respondents, 347 (58%) were HCPs, 251 (42%) were individuals with LE. Up to 74.3% of HCPs reported not actively screening for BED/BN. SCOFF questionnaire was reported to be the most used standardised tool for identifying potential BED/BN. HCPs reported referral as the main way of managing BED/BN, while LE participants reported using self-help for BED and referral for BN. Differences in practices between BED/BN are reported among HCPs and LE, such as identification practices, as are differences in HCP and LE perspectives, such as ways to manage BED. Conclusion: There are considerable variations in primary care practice for identifying and managing BED/BN. Providing clear guidelines for both HCPs and patients should be prioritised to ensure consistent care delivery.

P133

Using Eye-Tracking Tasks To Investigate Body Image And Appearance Evaluation In Young People With Anorexia Nervosa
Stephanie Miles^1,2, Erica Neill^1-3, Melissa Kirkovski⁴, Won Ying Qing^1,2,5, Andrea Phillipou^1-3
¹Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Australia, ²Centre for Youth Mental Health, The University of Melbourne, , Melbourne, Australia, ³Parkville Youth Mental Health & Wellbeing Service, Melbourne, Australia, ⁴Deakin University, Melbourne Burwood Campus, Melbourne, Australia, ⁵School of Psychological Sciences, The University of Melbourne, , Melbourne, Australia

Introduction: Poor body image is a core characteristic of anorexia nervosa (AN), yet it remains unclear how people with AN process images of bodies. This study aims to investigate the eye movements and visual scanning patterns of young people with AN when viewing images of their own and others bodies. It is hypothesised that, compared to controls, young females with AN will demonstrate hyper scanning, which will be more pronounced when viewing their own bodies. Methods: This cross-sectional study will include 26 females with a diagnosis of AN (aged 12-25) and 26 female healthy controls with no current or past mental illness. Participants will complete an eye tracking task that will include images of women at various shapes/weights, and participants will have the choice to include a photo of themselves in the task stimuli set. Results: Data collection is currently underway. Planned analyses include group comparisons on fixation count and duration to determine scanning behaviour to own and other peoples’ bodies. Conclusions: This research will progress our understanding of visual processing in young people with AN. If hyper scanning is evident, there are treatment implications including possible utilisation of attention-based interventions (e.g. cognitive bias modification) or visual exposure therapies to support improvements in visual scanning and body image processing.

P134

Executive Functioning In Eating Disorders: A Case-Control And Latent Profile Analysis
Rita C. Slof-Op 't Landt^1,2, Romy Dofferhoff¹, Alexandra E. Dingemans^1,2
¹Rivierduinen Eating Disorders Ursula, Leiden, Netherlands, ²Leiden University Medical Center, Department of Psychiatry,, Leiden, Netherlands

Introduction: Previous research has reported impairments in executive functioning in individuals with eating disorders (EDs), although findings are heterogeneous. Moreover, most studies have focused on single diagnoses, predominantly AN, and/or isolated executive domains. This study examined cognitive flexibility, inhibitory control, and decision-making in a mixed clinical sample of EDs and a healthy control group. Methods: Neuropsychological tasks (Trail Making Test, Wisconsin Card Sorting Test, Iowa Gambling Task, and Go/No-Go task) were administered to 185 patients initiating ED treatment (62 AN, 43 BN, 33 BED, 47 OSFED) and 65 controls (matched for sex, age, and education). Group differences between patients and controls and across diagnostic subgroups were examined. Latent profile analyses were conducted to explore potential underlying profiles of executive functioning. Results: No significant differences were observed between patients and controls or between diagnostic subgroups on the executive functioning measures. Although preliminary latent profile analyses suggested the presence of multiple executive functioning profiles, their validity and robustness could not be clearly established. Conclusions: The present study found no evidence for differences in executive functioning between patients with EDs and matched healthy controls. These findings suggest that executive functioning difficulties are only present in a small minority and seem to be independent of ED pathology.

P135

Exploring Longitudinal Relationships Between Gastrointestinal-Specific Anxiety And Eating Disorder Symptoms Using A Bivariate Latent Change Score Approach
Sophie R Abber, Madeline Palermo, Christina E Wierenga
Department of Psychiatry, University of California, San Diego, San Diego, CA, United States

Introduction: Gastrointestinal (GI) symptoms are thought to be bidirectionally related to eating disorder (ED) symptoms. GI-specific anxiety may contribute to ED symptoms by increasing engagement in ED-related avoidance behaviors (e.g., restriction) to prevent or reduce GI symptoms, which alleviate GI-specific anxiety in the short term but exacerbate it in the long term. We examined longitudinal, reciprocal relationships between GI-specific anxiety and ED symptoms. Method: Participants were 1010 adolescents and adults (86% female, 81% White, M_age=21; 55% anorexia nervosa, 13% bulimia nervosa, 12% avoidant/restrictive food intake disorder, 20% other specified feeding or eating disorder). Bivariate latent change score models tested associations between Visceral Sensitivity Index (VSI; a measure of GI-specific anxiety) score and Eating Disorders Examination-Questionnaire (EDE-Q) Global score at 5 timepoints: before, during, and after intensive treatment and at 6- and 12-month follow-up. Results: The best fit bivariate model was a dual coupling model, suggesting a bidirectional relationship between GI-specific anxiety and ED symptoms. Higher GI-specific anxiety predicted subsequent increases in ED symptoms, while higher levels of ED symptoms predicted subsequent reductions in GI-specific anxiety. Conclusions: GI-specific anxiety and ED symptoms are closely related during and after intensive ED treatment. GI-specific anxiety could exacerbate ED behaviors and may be an important intervention target.

P136

PErson-SpecifIC EFfEcts Of Tiktok Use And Eating Disorder Symptoms: A Daily Diary Study
Noa Brittain
University of Melbourne, Melbourne, Australia

Introduction: Recent studies suggest that exposure to eating and appearance related content on TikTok may intensify eating disorder symptoms. However, research is limited by 1) very few longitudinal studies, 2) reliance on self-report social media use measures, and 3) a conflation of between and within person effects. These limitations hinder our understanding of the (bi)directionality of TikTok use and symptom change, the timescale of effects, what patterns of use are more strongly associated with symptom change, and how these processes unfold within individuals. Our study investigates the person-specific bidirectional relationship between engagement with eating and appearance related content and eating disorder symptoms. Methods: We conducted an intensive longitudinal study, collecting daily self-reported symptoms and TikTok data over the course of a month. Data donations, requested from TikTok by participants, provided us with an objective account of the content participants viewed and how it was engaged with. We aim to recruit 300 participants; currently 101 participants with a diagnosed eating disorder and 71 healthy controls have been recruited, yielding 2298 timepoints in total. We plan to use dynamic structural equation modeling to model lagged and person-specific effects. Results: Analyses are expected to be completed by January 2027. Conclusions: This research will contribute to informing individualized and targeted prevention and intervention efforts.

P137

Digital Phenotyping Binge-Eating Episodes Highlights Heterogeneity In Affect And Dietary Restriction: An Ecological Momentary Assessment Study
Telma Cruz¹, Eugene Kang², Seunghyeon Kim², Marianne Rouleau-Tang^2,3, Elizabeth W. Lampe², Stephanie M. Manasse⁴, Adrienne S. Juarascio⁵, Emily Presseller²
¹University of Porto, Porto, Portugal, ²Dartmouth College, Hanover, NH, United States, ³University of Toronto, Toronto, ON, Canada, ⁴Nemours Children's Health, Willmington, DE, United States, ⁵Oregon Research Institute, Springfield, OR, United States

Introduction: Extant theories of binge eating (BE) highlight dietary restriction, affect, and body image concerns as antecedents that maintain BE. Digital phenotyping offers the opportunity to identify heterogeneous profiles of BE episodes from patterns across known antecedents. Methods: 30 adults with BE-spectrum eating disorders completed ecological momentary assessments of affect, dietary restriction, body image concerns, and BE for 4 weeks. K-means clustering was conducted on the lagged (for temporal precedence), raw, individual antecedent variables for all BE episodes (N=319). Results: The five cluster solution was selected from the elbow plot: Body-Driven Dieting (n=76, 23.8%) characterized by dietary restriction (M_r_ange=3.33-3.58) and body image concerns (M_range=4.49-4.83); Restricting and Dysregulated (n=40, 12.5%) characterized by restriction (M_range=4.07-4.15), positive affect (M_range=2.55-3.80), and negative affect (M_range=2.58-3.95), Feeling Fine (n=84, 26.3%) characterized by moderate positive affect (M_range=2.79-3.21), Body-Related Shame (n=38, 11.9%) characterized by shame (M=3.97), guilt (M=4.08), upset (M=3.45), and body image concerns (M_range=4.61-4.84), and Bad Body Image (n=101, 31.7%) characterized by elevated body image concerns (M_range=3.65-4.70) only. 78.9% of participants engaged in more than one type of BE (M=2.60, SD=1.43). Conclusions: Findings highlight within- and between-person heterogeneity in BE antecedents and substantiate the relevance of positive affect to BE.

P138

Affective Lability And Light Activity In Eating Disorder Inpatients: An Ecological Momentary Assessment (Ema) Study
Ingrid Funderud¹, Kristin Stedal¹, Line Wisting^1,2, Joseph Wonderlich^3,4
¹Regional Department of Eating Disorders, Division of Mental Health and Addiction, Oslo University Hospital, Ullevål HF, Oslo, Norway, ²Department of Psychology, Oslo New University College, Oslo, Norway, ³Division for Biobehavioral Research, Sanford Research, Fargo, ND, United States, ⁴Department of Psychiatry, University of North Dakota School of Medicine and Health Sciences, Fargo, ND, United States

Introduction: Individuals with eating disorders often experience marked affective instability. This study examined whether engaging in light post-meal physical activity influences day-level fluctuations in negative affect among inpatients receiving specialist treatment for eating disorders. Methods: Thirty-three inpatients completed ecological momentary assessment (EMA) of affect and post-meal activity over a two week period. Affective lability was modeled using Probability of Acute Change (PAC) and Mean Square Successive Difference (MSSD). Mixed-effects regression models examined whether activity (within- and between person) and time (EMA day) predicted acute shifts and overall variability in negative affect. Results: Higher-than-usual post-meal activity within individuals predicted a lower likelihood of acute affective shifts (B = –0.098, SE = 0.035, p = .005). In contrast, higher average activity levels across individuals predicted lower overall negative affect (B = –1.073, SE = 0.487, p = .033). Conclusion: These findings indicate that light activity following meals may help stabilize affect. However, changes in affect alone may not translate into symptom improvement without concurrent behavioral change. The study also highlights the utility of real-time measures of affective instability in understanding treatment processes in eating disorder populations.

P139

Title:Ultra-Processed Foods Consumption In Individuals With Binge Eating Spectrum Conditions From A Metropolitan City In Brazil
Camilla Haddad, Carla Mourilhe, Cleverton M Barbosa, Walter Gonçalves, Carlos E F Moraes, Jose Carlos Appolinario
Obesity and Eating Disorders Group, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil

Ultra-processed foods (UPF) consumption is frequently associated with binge eating spectrum conditions (BESC), such as bulimia nervosa (BN), binge eating disorder (BED), and recurrent binge eating (RBE). However, this relationship has not yet been investigated in the general population from middle-income countries. Thus, this study compared the consumption of UPF during binge eating episodes and non-binge meals across individuals with BESC from Rio de Janeiro, Brazil. BESC were assessed using the QEWP-5 and the SCID-P adapted for the DSM-5-TR. Food consumption during representative objective and subjective binge eating episodes (OBE and SBE) as well as in non-binge meals was investigated using a dietary recall method. The food items reported were classified as UPF according to the NOVA classification system. The Wald chi-square test was used to compare between-groups differences. Participants comprised 2,297 adults, including 136 with BESC (BED=29, BN=17, RBE=90). Individuals with BESC consumed a significantly higher proportion of UPF than those without BESC in non-binge eating meals (25.4% vs. 20.2%, p=0.002). Moreover, there was no difference in UPF consumption across BESC in OBE (BED=32.6X%, BN=43.7%, RBE=37.6%, p=0.27) and SBE (BED=16.8%, BN=38.2%, RBE=23.2%, p=0.09). In conclusion, BESC were associated with a higher consumption of UPF than the general population in regular meals. Furthermore, in OBE/SBE, the amount of UPF consumed is substantially higher, regardless of the diagnosis.

P140

A Systematic Review And Grade Assessment Of Problematic Smartphone Use In Eating Disorders
Johanna L Keeler^1,2, Laura Conde Ludtke³, Qingyu Yang³, Valentina Raschke Rameh³, Rebecca Ward³, Janet Treasure^2,4, Ben Carter⁵
¹Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, LVR University Hospital Essen, University of Duisburg-Essen, Essen, Germany, ²Centre for Research in Eating and Weight Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom, ³Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom, ⁴South London and Maudsley NHS Foundation Trust, London, United Kingdom, ⁵Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom

Background: Maladaptive patterns of smartphone use, or “problematic smartphone use” (PSU), disproportionately impacts young people and is associated with poor mental health. Emerging evidence suggests that PSU also influences eating patterns and contributes to symptoms associated with eating disorders (EDs). Methods: In this systematic review, we searched three databases for studies reporting data on PSU and ED psychopathology, including ED-related outcomes (eg, body dissatisfaction, emotional eating, and food addiction). Results: Thirty-five studies met the eligibility criteria, with almost all reporting cross-sectional data in nonclinical samples (n=52,584; mean±SD age 17.0±5.5 years). In these samples, studies reported a positive association between PSU and ED psychopathology, which was largely consistent across age groups and countries. Positive associations were also found between PSU and outcomes including food addiction (less consistent), body dissatisfaction, uncontrolled eating, and emotional overeating. Smartphone screen time was consistently related to higher ED psychopathology. According to a GRADE assessment, outcomes were rated as low certainty due to the cross-sectional nature of studies. Conclusions: PSU and greater smartphone screen time are associated with higher ED symptoms, body image dissatisfaction, and broader disordered eating behaviors in nonclinical populations. Prospective studies in clinical populations should consider including measures of PSU.

P141

What Counts As &Ldquo;Plus-Size&Rdquo;? Mapping Definitions And Psychological Responses To Body Representation
Wenn Lynn Ooi, Philip Koe-Leong, Julian Simmons, Isabel Krug
The University of Melbourne, Melbourne, Australia

“Plus-size” is a socially constructed subset of body diversity referring to larger body types. This systematic review examined how “plus-size” is operationalised in the literature and synthesised responses to plus-size representation on body image and weight-related attitudes. We also explored potential mediators/moderators and assessed study quality. PRISMA-guided searches were conducted in PsycINFO, MEDLINE, Embase, and Web of Science. Studies were excluded if they did not include visual plus-size content or focused on body positivity without a clear plus-size emphasis. Quality was assessed using the Critical Appraisal Skills Programme Checklist. Thirty-five studies (31 articles) were included. Operationalisation of “plus-size” relied largely on subjective, perceptual methods, showing substantial inconsistency. Exposure to plus-size images was generally associated with positive or non-significant effects on body image and weight-related attitudes. Evidence on mediators and moderators was limited. Methodological concerns included limited attention to gender and cultural diversity and an over-reliance on experimental designs. Plus-size representation may have beneficial effects on body image and weight-related attitudes, but findings depend on how “plus-size” is defined. Future research should prioritise standardised definitions, greater demographic diversity, and methodologies with stronger ecological validity.

P142

Emotionally Detached Dominance Is Associated With Eating Pathology Among Adolescent Boys
Caitlin Martin-Wagar¹, Ash Peters¹, Michael Kern², Lisa Damour³, Ruth Striegel Weissman⁴
¹University of Montana, Missoula, MT, United States, ²Interlochen Center for the Arts, Interlochen, MI, United States, ³Untangled Media Group, Cleveland, OH, United States, ⁴Wesleyan University, Middletown, CT, United States

Introduction. While investigations focused on eating disorders (EDs) among men are increasing, little focus on adolescent boys has remained. With adolescence being a high-risk developmental period for the emergence of ED symptoms and an increased social pressure for traditional gender norms among youth, this project sought to examine endorsement of male role norms and ED symptoms among high-school-aged boys. Methods. Self-report (N = 1,035) of symptoms (Eating Disorder Examination Questionnaire; Eating for Muscularity Scale; Male Body Attitudes Scale) and beliefs (Male Role Norms Inventory-Adolescent-Revised) were collected from adolescent boys at three schools in different regions of the United States of America. Results. A multivariable linear model was conducted to examine the relationship between emotionally detached dominance and eating pathology, muscularity, and body image. The overall model was significant, F (3, 942) = 28.92, p <.001, with emotionally detached dominance independently related to each. Conclusions. Given the association between emotionally detached dominance and eating pathology, male role norms need continued investigation to determine if and how they may be a risk factor for eating pathology and muscle dysphoria among adolescent boys. Future research should examine longitudinal relationships between these variables to determine if emotionally detached dominance is temporally related to the development and maintenance of ED symptoms.

P143

Quality Of Life In Adults With Eating Disorders
Renee D. Rienecke^1,2, Timothy D. Brewerton³, Alan Duffy¹, Thomas Joiner⁴, Jamie Manwaring^1,5, Phil S. Mehler^1,5, Dan V. Blalock^6,7
¹Eating Recovery Center/Pathlight Mood & Anxiety Centers, Denver, CO, United States, ²Northwestern University, Chicago, IL, United States, ³Medical University of South Carolina, Charleston, SC, United States, ⁴Florida State University, Tallahassee, FL, United States, ⁵University of Colorado, Denver, CO, United States, ⁶Center of Innovation to Accelerate Discovery and Practice Transformation, Durham Veterans Affairs Medical Center, Durham, NC, United States, ⁷Duke University School of Medicine, Durham, NC, United States

Introduction: A dearth of information exists on differences in quality of life (QoL) across eating disorder (ED) diagnoses. The purpose of the current study was to examine QoL among a large sample of adults with one of six ED diagnoses: anorexia nervosa-restricting subtype (AN-R), AN-binge/purge subtype (AN-BP), bulimia nervosa (BN), binge eating disorder (BED), avoidant/restrictive food intake disorder (ARFID), and otherwise specified feeding or eating disorder (OSFED). Methods: Participants were 1268 adults receiving treatment for an ED across multiple levels of care who completed a measure of QoL, the WHOQOL-BREF, at admission. Results: Adjusted pairwise comparisons with multiple comparison correction found significant differences among ED groups, even after controlling for age, sex, level of care, body mass index (BMI), and the interaction between BMI and ED diagnosis. Among the five significant findings, four of them involved differences in those with ARFID in comparison to the other ED diagnoses. On the physical health subscale, individuals with BN scored significantly better than did individuals with ARFID. On the psychological subscale, patients with ARFID had significantly better QoL than those with BN, BED and OSFED. On the social relationships subscale, the BED group scored significantly worse than those with AN-BP. Conclusions: This large study of adults with EDs suggests that there are meaningful differences among ED diagnostic groups on QoL.

P144

Examining The Relationship Between Impulsivity, Negative Affect, And Binge Eating: Findings From A Sample Of Adults With Clinical Binge-Spectrum Eating Disorders
Marianne Rouleau-Tang^1,2, Elizabeth W. Lampe¹, Stephanie M. Manasse³, Adrienne S. Juarascio⁴, Emily K. Presseller^1,5,6
¹Dartmouth College, Center for Technology and Behavioral Health, Hanover, NH, United States, ²University of Toronto, Department of Nutritional Sciences, Toronto, ON, Canada, ³Nemours Children’s Health, Wilmington, DE, United States, ⁴Oregon Research Institute, Springfield, OR, United States, ⁵Geisel School of Medicine at Dartmouth, Department of Biomedical Data Science, Hanover, NH, United States, ⁶Geisel School of Medicine at Dartmouth, Department of Psychiatry, Hanover, NH, United States

Introduction: Despite strong evidence supporting a link between impulsivity and binge eating (BE), it is unclear which facets of impulsivity are most strongly associated with BE and whether baseline impulsivity moderates the momentary associations between negative affect (NA) and BE. Methods: Participants (N=30 adults with binge-spectrum eating disorders) completed the Eating Disorder Examination and the UPPS-P Impulsive Behavior Scale at baseline and four weeks of ecological momentary assessments assessing NA and BE. Univariate and multiple linear regression explored the associations between UPPS-P total and subscale scores and baseline BE frequency. A quadratic effect of lack of perseverance (LoP) was added due to non-linearity of residuals. Multilevel logistic regression models explored relationships between NA and BE and interactions between NA and impulsivity on BE. Results: Total impulsivity was not significantly associated with BE frequency (p=.13). LoP had a positive quadratic (b=17.71, p= .02) and negative linear association with BE frequency (b=-92.35, p=.01). No other UPPS-P subscales were associated with BE frequency (ps>.05). Guilt predicted BE (b=0.04, p=.02), but impulsivity did not moderate this relationship (p=.13). Conclusions: Results suggest that increases in LoP are associated with increased BE frequency after a threshold in LoP is met. Future research should further explore the relationship between LoP and BE using multimodal data.

P145

Development And Implementation Of A Multifamily Therapy (Mft) Program In A University-Affiliatred Outpatient Clinic Specialized In Eating Disorders (Ed).
Veronika Steenpass¹, Marco Solca^1,2
¹Geneva University Hospital, Genève, Switzerland, ²Geneva University, Genève, Switzerland

Introduction : Multifamily therapy (MFT) brings together several families—patients, parents, and siblings—to engage in a shared therapeutic process. Activities draw on systemic approaches, including narrative, solution-focused, and mentalization-based therapies. Its effectiveness relies on group processes such as peer learning, multiples perspectives, and reduced anxiety through shared experience and support. Methods : Our outpatient clinic specialized in eating disorders introduced MFT in June 2025. Two cycles of six sessions were held (June–December 2025; March–June 2026). Program development required adjustments regarding the group setting, diagnoses included, and activities. We used the Manual of Multifamily Therapy as a reference, with team training and supervision by Solange Cook-Darzens. Results : Verbal feedback from the first cycle highlighted relief through shared experiences. We observed improved engagement, especially among “difficult” families. This led to strengthening pre-commitment and adopting a closed-group format. To enhance empathy, the second cycle included only families of patients with anorexia. Some activities were adapted based on therapeutic impact. Discussion : A tabular overview of both cycles (dates, number of families, objectives, activities) supports discussion with professionals developing MFT programs.

P146

Feeding The Mood: The Role Of Parental Emotion Socialization In Children&Rsquo;S Food Avoidance Behaviors
Juliette Taquet, Kim Dierickx, Lien Goossens, Sandra Verbeken
Department of Developmental, Personality and Social Psychology - Ghent University, Gent, Belgium

Objective: This observational study examined how young children’s avoidance-oriented behaviors during mealtimes relate to emotion-related parenting practices and the emotional family climate. Methods: Forty-four parent–child dyads (children aged 2.5–8 years) were video-recorded during two home mealtimes: one with a preferred (“like”) and one with a non-preferred (“dislike”) meal. Parenting practices, emotional climate, and children’s avoidance behaviors were behaviorally coded. A within-subjects design compared behaviors across conditions, and linear mixed models assessed condition effects and associations. Results: During “dislike” meals, children showed more diverse food avoidance and complaining, while parents displayed both more supportive (e.g., helping, affirming) and unsupportive (e.g., minimization, controlling) practices. Emotional family climate did not differ between conditions. Across conditions, higher use of both supportive and unsupportive practices was associated with greater diversity in avoidance behaviors, whereas a more positive emotional climate was linked to less diversity. Conclusions: Children and parents showed greater behavioral variability during disliked meals. While parenting practices varied by condition, their associations with child behavior were consistent. A positive emotional climate may play a protective role, highlighting the importance of the broader mealtime context and the need for longitudinal research.

P147

Introducing Family-Based Treatment For Youth With Anorexia Nervosa In Germany And Switzerland: Rationale, Implementation, Outcomes, Challenges And Facilitators
Qian Zhao¹, Alexandra Zangl¹, Verena Haas¹, Linus Imken¹, Helene Tzieropoulos Osterlof², Kerstin Jessica Plessen², Dagmar Pauli³, Nicole Besse-Fluetsch³, Daniel Le Grange^1,4,5, Christoph U. Correll^1,6,7,8,9,
¹Charité-Universitätsmedizin Berlin, Berlin, Germany, ²Department of Child and Adolescent Psychiatry, Lausanne University Hospital (CHUV), University of Lausanne, Lausanne, Switzerland, ³Department of Child and Adolescent Psychiatry, Psychiatrische Universitätsklinik Zürich, Zurich, Switzerland, ⁴Department of Psychiatry and Behavioral Sciences, University of California, San Francisco , CA, United States, ⁵Department of Psychiatry and Behavioral Sciences, The University of Chicago, Chicago, IL, United States, ⁶German Center for Mental Health (DZPG), Berlin, Germany, ⁷German Center for Child and Adolescent Health (DZKJ), Berlin, Germany, ⁸Einstein Center for Population Diversity (ECPD), Berlin, Germany, ⁹Northwell, New Hyde Park, New York , NY, United States, ¹⁰Department of Psychiatry and Molecular Medicine, Donald and Barbara, Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, NY, United States

Background: FBT is the most efficacious outpatient treatment for youth with anorexia nervosa (AN), yet its implementation remains largely limited to Anglo-Saxon countries. This study examined FBT implementation in Berlin, Lausanne, and Zurich, reporting outcomes, implementation barriers and facilitators.
Methods: 67 youth (8–17 years) with AN received FBT in three university AN-specialized outpatient settings. Anthropometric measures and the Eating Disorder Examination-Questionnaire (EDE-Q) were assessed at baseline and longitudinally (3–12 months). In our poster, within/across site outcomes will be presented.
Results: FBT was integrated into existing frameworks at all sites; reimbursement was available in Lausanne and Zurich. Most patients were female (87–96%), with a median age of 14.5–15.0 years. Berlin had the lowest %mBMI (79.9±4.8) and highest psychiatric comorbidity rate (48.4%); Lausanne had the highest EDE-Q score (4.4); Zurich had the fewest comorbidities (18.2%) and shortest treatment duration (92.3±5.7 days). Over time, all cohorts showed weight gain and reduced psychopathology. Implementation barriers included resource limitations, systemic skepticism and lack of trained therapists; facilitators were institutional support, a strong FBT evidence base and parent empowerment.
Conclusions: FBT was successfully implemented across three European sites. Barriers and facilitators were identified that may help guide future sites introducing FBT in non-Anglo-Saxon settings.

P148

Emotional&Ndash;Cognitive Profiles And Childhood Trauma Predict Response To Crest In Inpatient Anorexia Nervosa
Paolo Meneguzzo¹, Elena Tenconi¹, Elisa Bonello², Patrizia Todisco²
¹Department of Neuroscience, University of Padova, Padova, Italy, ²Casa di Cura Villa Margherita - KOS Group, Arcugnano, Italy

Objective: Treatment response in AN is heterogeneous, especially for interventions targeting emotional and cognitive mechanisms. We examined whether emotional-cognitive profiles and childhood trauma were associated with response to Cognitive Remediation and Emotion Skills Training (CREST). Methods: We studied 198 female inpatients with AN in an 8-week programme including group CREST. Cluster analysis used emotion dysregulation (DERS), alexithymia (TAS-20), cognitive rigidity (DFLEX), and obsessive-compulsive symptoms (OCI-R). Changes in EDE-Q, DFLEX, TAS-20, and BMI were compared across clusters. Childhood trauma (CTQ) was tested as predictor and moderator. Results: Three profiles emerged: low, moderate, and global impairment. Clusters differed in BMI, illness duration, EDE-Q, and trauma exposure (all p<.05). BMI and EDE-Q improved similarly across clusters (ΔBMI: H=3.41, p=.182; ΔEDE-Q: H=0.28, p=.868), whereas psychological outcomes differed significantly. Improvements were greater in the globally impaired profile for cognitive rigidity (ΔDFLEX: H=63.68, p<.001) and alexithymia (ΔTAS-20: H=33.85, p<.001). Emotional abuse predicted moderate impairment; physical abuse predicted global impairment. Higher abuse exposure attenuated improvements in DFLEX and TAS-20 in the more impaired profiles. Conclusion: CREST-related psychological change in AN appears profile-dependent and trauma-sensitive. Profiling and trauma assessment may help personalize inpatient treatment pathways.

P149

Reconceptualizing Eating Disorder Prevention: A Gamified Transdiagnostic Intervention To Enhance Mental Health Literacy In Children And Adolescents
Lorenz Ackermann¹, Ursula Prinz ², Nino Werner², Alexandra Gössl², Gudrun Wagner¹, Andreas Karwautz ¹, Karin Waldherr², Michael Zeiler¹
¹Medical University of Vienna , Vienna, Austria, ²Ferdinand Porsche FERNFH, Wiener Neustadt, Austria

Introduction: Universal eating disorder (ED) prevention programs have shown limited efficacy and engagement, and may even pose risks when focusing on eating and exercise habits. Gamified approaches targeting transdiagnostic factors (e.g., emotional/social difficulties) may offer a promising alternative. This study describes the development of a serious game (SG) to promote mental health (MH) literacy in youth, with potential for ED prevention. Methods: We conducted five focus groups with children (n=37, 10-14 years) and a survey with school stakeholders (n=60) to identify key MH challenges, requirements for the SG (engaging game mechanics and features), and stakeholders’ attitudes toward SGs and their successful school-based implementation. Results: Key MH challenges identified include school-related stress, performance pressure, peer difficulties, anxiety, and domestic problems. Children preferred an open, exploratory game environment with creative freedom and strategy-based missions. Stakeholders showed moderate support for an SG approach; cooperation with MH professionals, training in SG delivery, and a hybrid implementation model (school- and home-based) were considered most feasible. Conclusion: These findings informed SG development combining an overarching fantasy storyline with exploratory and tower-defense mechanics to foster skills for actively promoting MH and coping with challenging emotions and stress. The SG may serve as a transdiagnostic prevention approach in MH, including EDs.

P150

Understanding Eating Disorder Experiences Of Personal Recovery Through Patient Perspectives: A Thematic Analysis Of Online Forum Groups
Gaia Albano¹, Chiara Tosi², Mariarita Semola¹, Valentina Cardi², Gianluca Lo Coco¹
¹Department of Psychology, Educational Science and Human Movement, University of Palermo, Palermo, Italy, ²Department of General Psychology, University of Padova, Padova, Italy

Introduction: This study aimed to explore how individuals make sense of their ED and negotiate interpersonal difficulties within a peer-led online forum. Method: This qualitative study analyzed transcripts from 32 weekly online forum groups involving 37 participants with EDs or subthreshold disordered eating, facilitated by recovered peer mentors as part of the INTERconNEcT-EDs trial. Data were examined using Reflexive Thematic Analysis. Results: Five main themes were identified: The first was that ED provided familiarity and safety (The Trap of the Eating Disorder). The second was that illness maintenance factors contributed to a passive positioning and identification with the illness (The Eating Disorder as an Emotional Regulator). In the the third theme despite fears of judgement, the forum experience enabled safe relational experimentation, fostering connection and mutual recognition (The Role of Social Relationships). The fourth theme was a shift towards values-based living and meaning reconstruction (Values and Commitment). Finally, the last theme revealed a gradual transition from an ED identity to a more flexible sense of self (Blurred Boundaries Between Identity and the Eating Disorder). Conclusions: Recovery emerged as a dynamic, non-linear process characterized by increasing psychological flexibility and relational engagement. Findings highlight the need for interventions that move beyond symptom reduction to support the development of a meaningful life beyond the disorder.

P151

Project Embraced: A Proposal For A Single-Session Intervention Addressing Minoritized And Intracommunity Stress Among Lgbtq+ People With Eating Pathology
Wesley Barnhart¹, Genevieve Nowicki², Myalin Lawrence¹, Kathryn Pasquariello¹, Nathalie Gullo^1,3
¹Suffolk University, Boston, MA, United States, ²Northeastern University, Boston, MA, United States, ³Washington University, St. Louis, MO, United States

Lesbian, Gay, Bisexual, Transgender, and Queer (LGBTQ+) people experience greater eating pathology relative to their heterosexual and cisgender peers. Minoritized stress theory postulates that identity-specific stressors originating outside and within the LGBTQ+ community contribute to these disparities but eating disorder (ED) treatments often fail to address these disparities and are inaccessible to minoritized communities. We developed and will test an online single-session intervention (SSI) targeting minoritized and intracommunity stress for LGBTQ+ people with eating pathology (N=150). This brief (20-minutes) SSI explains identity-specific stressors and their impacts on eating pathology through psychoeducation and fictional “peer vignettes” – short stories based on clinical and lived experiences among LGBTQ+ individuals, developed with a community advisory committee (n=7 LGBTQ+ people with lived ED experiences). SSI exercises include self-reflection, advice-giving, and coping plan development. Internalized heterosexism and identity pride will be assessed immediately pre- and post-SSI. Eating pathology will be assessed at 1-week, 1-month, and 3-months follow-up. If efficacy is supported, this accessible and culturally-competent online self-guided resource could be integrated into online ED screening tools and offered as a first-line resource for LGBTQ+ people with eating pathology or delivered alongside existing ED treatments to improve treatment outcomes for LGBTQ+ people.

P152

Parental Mealtime Behavior Changes In The Context Of Fbt-Arfid
HaLi Boyce¹, Ainsley Cogburn¹, Megan Ruiz Fischer¹, Anni Liu², Natalie Saba², Josie Castro Sanchez¹, Nandini Datta¹, Brittany E. Matheson¹, James D. Lock¹
¹Stanford University School of Medicine, Stanford, CA, United States, ²Palo Alto University-Stanford PsyD Consortium, Palo Alto, CA, United States

Introduction: Family Based Treatment for Avoidant/Restrictive Food Intake Disorder (FBT-ARFID) is an effective treatment for children with low-weight ARFID that encourages parents take charge of mealtimes to increase intake. However, no studies have assessed changes in parental mealtime behaviors pre- and mid- FBT-ARFID. Methods: Twenty families participating in a randomized clinical trial for children 6-12 with low-weight ARFID recorded naturalistic meals prior to and mid-way through FBT-ARFID. Six coders double-coded videos with consensus for the following: meal structure (ex. people present, length of mealtime, location, meal composition and consumption) and parental behaviors (ex. food preparation, physical encouragement, encouragement to eat, criticism, and warmth). Results: Children (n=20; 9.5 y ± 2.1y) identified as mostly White (75%), non-Hispanic (75%), and living in intact households (90%). Mealtimes averaged 29.2 minutes (SD=16.5) at baseline and 27.6 minutes (SD=8.3) mid-treatment. Parents almost tripled their rate of physical (M=1.3, SD=2.5 to M=3.7, SD= 5.4) and almost doubled their rate of verbal prompts (M=4.7, SD=5.5 to M=8, SD=11.3) to eat from baseline to mid-treatment. Expressed warmth (M=1.9, SD=2.3 to M=4.3, SD=3.9) and criticism (M=0.6, SD=0.9 to M=2.2, SD=4.8) increased from baseline to mid-treatment. Conclusions: These findings suggest that parents may change mealtime behaviors during FBT-ARFID treatment, which deserves further examination in future studies.

P153

A Phase 2, Open-Label, Multi-Site Safety And Feasibility Study Of Mdma-Assisted Internal Family Systems (Ifs) Therapy For Young Adults With Anorexia Nervosa
Victoria Burmester¹, Anya Ragnhildstveit², Reid Robison³, Camilla Lindvall Dahlgren⁴, Julia Deakin⁵, Jamarie Geller⁶, Ivar W Goksøyr⁷, Miriam Kaiyo⁸, Ariana Elias⁹, David Erritzoe¹, David Nutt¹, Allan Young¹, Michael C Mithoefer¹⁰, Dasha Nicholls¹, Liliana G Galindo^2,5
¹Department of Brain Sciences, Imperial College, London, United Kingdom, ²Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom, ³Department of Psychiatry, The University of Utah School of Medicine, Salt Lake City, UT, United States, ⁴Department of Psychology, Oslo New University College, Oslo, Norway, ⁵Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, United Kingdom, ⁶Department of Psychiatry, The University of Michigan, Ann Arbor, MI, United States, ⁷Nordre Østfold DPS, Østfold Hospital Trust, Gralum, Norway, ⁸Department of Family and Consumer Studies, The University of Utah, Salt Lake City, UT, United States, ⁹Specialty Outpatient Services, Centre for Eating Disorder Recovery, Tikvah Clinic, Sydney, Australia, ¹⁰Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, United States

Introduction: Anorexia nervosa (AN) has the highest mortality of any psychiatric disorder, yet no pharmacological treatments are approved, and fewer than half of individuals achieve full recovery. Internal Family Systems (IFS) therapy is an evidence-based, trauma-informed approach that conceptualises psychopathology as arising from distinct “parts” of the self that adopt protective roles to manage threat, shame, or emotional pain. Therapeutic recognition of these parts can reduce internal conflict, transform maladaptive coping, and improve psychological functioning. MDMA may support this process through enhanced prosociality, fear extinction, social reward learning and metaplasticity. This study aims to evaluate the safety and feasibility of MDMA-assisted IFS therapy in young adults with AN. Methods: This Phase 2, open-label study will enrol 45 adults aged 21–35 with clinically diagnosed AN who are medically stable. Participants will receive 3 preparatory IFS sessions, 3 MDMA dosing sessions, and 9 integrative IFS sessions (3 per MDMA dose). Treatment will span 16 weeks, with follow-up assessments at 1, 3, 6, and 12 months. Primary outcomes are safety, tolerability, and feasibility. Secondary outcomes include preliminary efficacy on eating disorder symptoms. Results: Recruitment is anticipated to commence pending funding and regulatory approvals. Conclusions: This study will provide the first evidence on MDMA-assisted IFS therapy in AN to inform future controlled trials.

P154

A Thematic Analysis Of Community Stakeholder Experiences In The Implementation Of Family-Based Treatment For Adolescent Anorexia Nervosa Delivered In The Home
Caroline Christian¹, AnnaLee Tapp², Abigail Neiser¹, Erin Stalvey¹, Jasmine Zhu¹, Christina Tortolani³, Elizabeth Mcguier¹, Amy Egbert⁴, Andrea Goldschmidt¹
¹University of Pittsburgh, Department of Psychiatry, Pittsurgh, PA, United States, ²University of Pittsburgh, Department of Psychology, Pittsurgh, PA, United States, ³Bryant University, Department of Psychology, Smithfield, RI, United States, ⁴University of Connecticut, Department of Psychological Sciences, Mansfield, CT, United States

Introduction. Family-based treatment (FBT) is the best-established treatment for adolescent anorexia nervosa (AN), but optimal implementation remains undertested, and access is limited by geographic constraints, cost, and lack of community providers. Home-based models of care can reduce barriers but have not yet been applied to FBT.
Methods. As part of a pilot RCT testing home-based FBT delivered through community settings, we conducted 30-60 minute qualitative interviews with project therapists, supervisors, and referral sources to inform future implementation efforts. Rapid Group Analysis Process (RapGAP) was used to transcribe, code, and identify themes.
Results. We identified 15 themes within 3 categories: 1) research administration; 2) perceived value of intervention; and 3) organizational fit. Within category 1, participants described positive relationships with the research team, while also reporting research-related challenges, such as concerns about randomization. Within category 2, stakeholders reported that home-based FBT filled a clinical gap, but had concerns about treatment fit for some families. Category 3 included mixed feedback on institutional support, time commitment, and referrals for follow-up care.
Conclusions. Interviews revealed important considerations for future implementation efforts and developing sustainable care models, such as providing more training and incentives for therapists and need for ongoing collaboration with families and stakeholders.

P155

Parental Burden And Skills During Home Treatment For Adolescents With Anorexia Nervosa (An) &Ndash; Findings From A Multicenter Rct
Brigitte Dahmen¹, Ingar Zielinski-Gussen^{1, 2}, Manuel Föcker³, Freia Hahn⁴, Tanja Legenbauer³, Ulf Thiemann⁵, Astrid Dempfle⁶, Beate Herpertz-Dahlmann¹
¹Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital, RWTH Aachen University, Aachen, Germany, ²Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University hospital, University Duisburg-Essen, Essen, Germany, ³LWL University Hospital Hamm for Child and Adolescent Psychiatry, Psychotherapy and Psychosomatics, Ruhr-University Bochum, Hamm, Germany, ⁴Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, LVR Clinic Viersen, Viersen, Germany, ⁵Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, LVR Hospital Bonn, Bonn, Germany, ⁶Institute of Medical Informatics and Statistics, Kiel University and University Hospital Schleswig-Holstein, Kiel, Germany

Introduction. Although caring for a child with anorexia nervosa (AN) places a significant burden on parents, improving parents’ skills in managing AN is associated with a better outcome. Home-visiting programs such as home treatment (HoT) aim to specifically strengthen parental skills through close involvement as co-therapists. This project investigated parental factors during HoT compared to treatment as usual (TAU; inpatient- and day-patient treatment, IP/DP). Methods. This randomized-controlled trial (RCT) included N=253 patients from five German clinics for child adolescent psychiatry. After a short IP phase, stabilized patients were randomized to continue in HoT (N=80) or TAU (N=81). Assessments took place throughout treatment and 12 months after admission. In addition to child outcomes, parental burden (BDI-II, EDSIS) and skills (AESED) were assessed and compared between arms. Statistical analyses were conducted in R. Results. Initial analyses show comparable parental skills and burden at follow-up between HoT and TAU, but significant differences across the treatment phase in favor of TAU. Associations with treatment arm and child-related variables are reported. Conclusions. Treatment for adolescents with AN should closely involve parents as co-therapists. The results of our study highlight the importance of considering parental variables to do so effectively. Implications and further research needs regarding home-visiting programs for young patients with AN are discussed.

P156

How Do Therapists Experience 20-Session Cognitive-Behavioral Therapy For Anorexia Nervosa (Cbt-An-20)? A Qualitative Study
Heather C Duggan¹, Hannah M Turner², Charlotte L Rose³, Jennifer J Thomas^4,5, Kamryn Eddy^4,5, Kathryn Pasquariello⁴, Kendra R Becker^4,5, Debra L Franko^4,6, Glenn Waller⁷
¹University of Sheffield, School of Psychology, Sheffield, United Kingdom, ²Hampshire and Isle of Wight Health NHS Foundation Trust, Southampton, United Kingdom, ³Avon and Wiltshire Mental Health Partnership NHS Trust, Bristol, United Kingdom, ⁴Eating Disorders Clinical and Research Program, Massachusetts General Hospital, Boston, MA, United States, ⁵Department of Psychiatry, Harvard Medical School, Boston, MA, United States, ⁶Northeastern University, Boston, MA, United States, ⁷University of Warwick, Department of Psychology, Coventry, United Kingdom

Understanding therapists’ experiences of delivering manual-based treatments is important for addressing any concerns and overcoming potential barriers to their effective delivery in clinical practice. CBT-AN-20 is a 20-session cognitive-behavior therapy (CBT) for outpatients with anorexia nervosa (Waller et al., 2026). We conducted an online survey of therapists (N = 10) who delivered CBT-AN-20 in a UK trial. We analyzed responses using descriptive statistics and thematic analysis (Braun & Clarke, 2006). Qualitative results highlighted three themes: Changing feelings about therapy over time; Beliefs about whom therapy might work for; and Perceptions of the characteristics of therapy. Therapists’ mixed feelings about delivering CBT-AN-20 suggest that it was feasible and broadly acceptable. They felt it worked well for motivated patients but less well for those ambivalent about recovery or with more complex presentations. Therapists experienced CBT-AN-20 as fast-paced yet structured, and comparable with CBT-T (Waller et al., 2019) and CBT-E (Fairburn, 2008). They found its focus on early weight regain difficult but worthwhile. However, they expressed concerns that the nature of CBT-AN-20 sometimes challenged the therapeutic relationship. Initial training and clinical supervision should address therapists’ concerns and build their confidence in delivering the therapy. Future research should explore who CBT-AN-20 works best for and whether therapists’ confidence changes with experience.

P157

Eating Disorders In An Immigrant Population: Are Clinical Features And Treatment Outcomes Different From The Native-Born Spanish Population?
Fernando Fernandez-Aranda^1,2, Magda Rosinska¹, Silvia Tempia Valenta³, Isabel Sanchez^1,2, Olga Jordana^1,2, Lucero Munguia¹, Anna Rita Atti³, Roser Granero^1,4, Lucia Camacho-Barcia¹, Susana Jimenez-Murcia^1,2
¹Department of Clinical Psychology, University Hospital of Bellvitge-IDIBELL and CIBERobn, Hospitalet de Llobregat, Spain, ²Department Clinical Sciences, School of Medicine and Health Sciences, University of Barcelona, Hospitalet de Llobregat, Spain, ³Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy, ⁴Department of Psychobiology and Methodology of Health Sciences, Autonomous University of Barcelona, Barcelona, Spain

Sociocultural factors, including migration and acculturation, may influence the clinical profile and course of eating disorders (EDs). This study examined differences between immigrant and native-born Spanish patients with EDs in clinical presentation and treatment response. Methods: Consecutive outpatients from the Eating Disorders Unit at Bellvitge University Hospital (Barcelona, Spain) were assessed using the EDI-2, Symptom Checklist-90-R (SCL-90-R), and TCI-R. Statistical analyses included chi-square tests, ANOVA, Cox regression for dropout, and logistic regression for predictors of poor outcome, adjusted for ED subtype. Results: The sample included 1104 patients (947 native-born; 157 immigrants). Immigrant patients showed a distinct clinical profile, with lower drive for thinness and body dissatisfaction but higher interpersonal distrust, maturity fears, perfectionism, anxiety-related symptoms, and self-transcendence. They also presented a worse treatment response, including higher dropout rates and lower remission rates. Predictive models identified different risk factors for poor treatment response in each group. Conclusions: Immigrant patients with EDs exhibit a differentiated clinical presentation and less favorable treatment response compared to native-born patients. The differential predictors of poor outcome highlight the need for culturally informed and individually tailored interventions that consider both sociocultural context and personality-related vulnerabilities

P158

Updated Dietetic Prescribing Guidelines When Naso-Gastric Tube Feeding Under Physical Restraint Is Required: A Modified Nominal Group Technique Study.
Sarah J Fuller^1,2, Ursula Philpot³, Helen West⁴
¹Imperial College, London, United Kingdom, ²Northamptonshire Healthcare NHS Foundation Trust, Northampton, United Kingdom, ³Leeds Beckett University, Leeds, United Kingdom, ⁴Kings College, London, United Kingdom

Introduction: Naso-gastric tube (NGT) feeding under physical restraint is clinical intervention sometimes needed for mental health patients, predominantly Anorexia Nervosa, whose resistance to nutrition is life-threatening. Research suggests that this was used past the point of medical stabilisation across mental health and paediatric wards in England during 2020-23, establishing a need to update the existing dietetic prescribing guidelines. Methods: Using a modified nominal group technique, 15 expert dietitians from across the UK were recruited. Four stages, namely silent idea generation, round-robin discussion, refinement of ideas, and consensus building, were followed to update the dietetic guidelines. Results: The updated guidelines now apply to all mental health diagnoses involving severe restrictive eating. New recommendations regarding weaning strategies were introduced, including: Stopping NGT feeding under physical restraint once medically stable Giving 7-days of nutrition over 6-days, enabling a day off from physical restraint Tolerating weight maintenance or sub-optimal pathway of weight restoration, rather than gain, to allow oral diet to be established. Overnight NGT feeding Conclusions: The updated guidelines provide a framework for legal, proportionate, and least restrictive dietetic prescribing. Including weaning strategies highlights the importance of supporting patients to establish a safe oral intake and not using this intervention for longer than clinically necessary

P159

Prevention Of Eating Disorders By Enhancing Protective Factors
Ata Ghaderi¹, Thomas Parling², Elisabeth Welch¹, Klara Edlund¹, Richard Bränström¹, Gerhard Andersson³
¹Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm , Sweden, ²Division of Psychiatry, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden, ³Department of Behavioral Sciences and Learning, Linköping, Sweden

Objective: To investigate the efficacy of a Internet-delivered prevention program based on the enhancement of protective factors such as body appreciation, compared to a credible minimal intervention. Method: A total of 644 young people (ages 15–20) with body dissatisfaction were randomized to a prevention intervention or control group. Assessments were conducted at baseline, after the intervention, and at 6 and 12 months. Long-term assessments (up to 3 years) are ongoing. The prevention program consisted of four 1-hour weekly individual digital sessions. Movie clips relevant to each topic (e.g., body appreciation) were presented, and participants were asked to reflect on them. They could also share their reflections anonymously with five other participants. Results: Preliminary results, using mixed-model analysis, indicated significantly better outcomes for the intervention compared to controls with respect to body appreciation, body dissatisfaction, and functionality appreciation, and non-significant improvements in self-compassion. However, no interaction effects were found for intuitive eating. The intervention group reported non-significant improvement in eating disorder symptoms measured by the EDE-Q. The primary outcome (incidence of ED), based on EDE interviews, will be reported when the long-term outcomes are available. Discussion: The prevention program resulted in the expected significant improvements in several protective factors, and the effects were maintained over time.

P160

Feasibility ANd Preliminary Efficacy Of A Digital Guided Self-Help Intervention FOr Dysregulated Eating ANd Weight Gain Prevention AMong Adolescents
Andrea K. Graham¹, Danielle A. N. Chapa², Lan Yu², Nathan Winquist¹, Chloe Hudson², Victoria Bell², Andrew Tyler², Katrina T. Obleada¹, Erin Stalvey², Graham Miller¹, Isabel R. Rooper¹, Adrian Ortega¹, Andrea B. Goldschmidt²
¹Northwestern University Feinberg School of Medicine, Chicago, IL, United States, ²University of Pittsburgh Medical Center, Pittsburgh, PA, United States

Introduction. Cognitive-behavioral therapy (CBT) is a promising treatment for dysregulated eating in adolescents, but reach is limited and developmental changes in self-regulation, which could inhibit adherence and outcome, are not addressed. To fill this gap, we created VIBE: Virtual Intervention for Binge Eating, a 16-week digital guided self-help intervention that targets CBT and self-regulation strategies. Methods. We are conducting a single-arm open pilot trial of VIBE with 50 adolescents to evaluate feasibility, acceptability, and preliminary efficacy (reducing dysregulated eating, preventing weight gain). Results. To date, we have enrolled 43 adolescents, with 13 VIBE completers and 1 withdrawal. Thus far, participants are 51% female and aged 15.69 (SD=1.93) at baseline. Most are non-Hispanic White (46%), non-Hispanic Black (30%), or Hispanic (13%). Preliminary data show good acceptability and engagement (75% scored above the acceptability threshold on the System Usability Scale; 85% engaged with VIBE components). Among 13 completers, preliminary data indicate significant large reductions in dysregulated eating episodes (z=-2.35; p=0.02; Cohen’s d=0.76) and moderate but non-significant reductions in BMI percentile (z=-0.56; p=0.58; Cohen’s d=0.45) from baseline to post-treatment. Conclusions. Early results support VIBE as a promising intervention for dysregulated eating and weight gain prevention among adolescents. Next steps are to test VIBE in a fully powered RCT.

P161

The Association Of Vitamin D Deficiency With Depressive Disorders In Patients With Eating Disorders: A Cross-Sectional Study
Sebastien Guillaume¹, Hala Kerbage², Isabelle Jaussent³, Rami Bou Khalil⁴
¹Emergency Psychiatry and Acute Care Department, Lapeyronie Hospital, Montpellier University Hospital Centre, Montpellier, France, ²Child and Adolescent Psychiatry Department, Saint Eloi University Hospital, Montpellier, France, ³Montpellier University, Institute for Neurosciences of Montpellier (INM), Inserm, Montpellier, France, ⁴1. Saint Joseph University, Psychiatry Department, , Beirut, Lebanon

Background: Vitamin D deficiency and depressive disorders are both common in patients with eating disorders (ED). However, the association between vitamin D status and current depressive disorder (CDD) in ED populations remains insufficiently explored. Methods: We conducted a cross-sectional study including 481 outpatients with EDs. Psychiatric diagnoses were established using the Mini-International Neuropsychiatric Interview . ED severity was assessed with the EDE-Q. Serum 25-hydroxyvitamin D levels were measured as part of routine clinical assessment, and vitamin D deficiency was defined as <20 ng/mL. Odds ratios (ORs) were estimated using logistic regression. Results: Vitamin D deficiency was significantly associated with higher odds of CDD (OR 1.98, 95% CI 1.20–3.28; p=0.008). This association persisted after adjustment for ED severity, psychiatric comorbidities, and season of assessment. No significant interactions were found between vitamin D deficiency and ED subtype, EDE-Q score, or season. Conclusions: Vitamin D deficiency was associated with the presence of a current depressive disorder in patients with eating disorders, independently of ED subtype, severity, and seasonality. These findings support the clinical relevance of assessing vitamin D status in patients with ED presenting with depressive symptoms. Longitudinal studies are needed to clarify the direction and clinical implications of this association.

P162

Early Change Predicts Overall Treatment Outcome In 15- Session Cognitive-Behavioral Therapy For Avoidant/Restrictive Food Intake Disorder
P. Evelyna Kambanis^{1, 2}, Stefania Yee¹, Jonathan Xiang¹, Kendra Becker^{1, 2}, Katherine Pasquariello¹, Ashley Dunford^{1, 2}, Kelly Armstrong¹, Madison Fisher¹, Brittani Martino¹, Elisa Asanza¹, Meghan Slattery¹, Kathryn Brigham^{1, 2}, Laura Holsen^{1, 2}, Elizabeth Lawson^{1, 2}, Kamryn Eddy^{1, 2}, Jennifer Thomas^{1, 2}
¹Massachusetts General Hospital, Boston, MA, United States, ²Harvard Medical School , Boston, MA, United States

INTRODUCTION: Early change is a robust predictor of eating disorder treatment outcome yet has not been examined in the context of psychological features of avoidant/restrictive food intake disorder. We investigated whether early change in food neophobia and ARFID profile severity in cognitive-behavioral therapy for ARFID (CBT-AR) each predicted overall change in their respective domains, hypothesizing that greater early change would be associated with greater end-of-treatment improvement. METHOD: Twenty-five patients (28% female; 92% white; M [SD] age = 13.60 [2.47] years) with ARFID sensory sensitivity (100%) and lack of interest in food/eating (4%) received CBT-AR and completed the Food Neophobia Scale (FNS) and Pica, ARFID, and Rumination Disorder Interview – ARFID Questionnaire (PARDI-AR-Q) at each session. Linear regressions examined whether early change (Session 5 – Session 1) predicted overall change (Session 15 – Session 1), controlling for baseline severity. RESULTS: Early change significantly predicted overall change in food neophobia (R² = 0.62, b = 0.77, p = .001), sensory sensitivity (R² = 0.64, b = 0.80, p <.001), and lack of interest in food/eating (R² = 0.69, b = 0.68, p <.001). CONCLUSIONS: Early symptomatic response may be a meaningful indicator of overall treatment outcome in CBT-AR, with implications for session-by-session monitoring and early identification of non-responders.

P163

Illness Severity, Treatment Motivation And Personality As Predictors For The Treatment Outcome In Adolescents And Young Adults With Anorexia Nervosa
Konstantin Kopp¹, Stefanie Trutmann¹, Tanja Wittek¹, Julia Klang¹, Helene Krauss¹, Carina Aichinger¹, Isolde Kostner¹, Ulrike Schmidt², Andreas Karwautz¹, Michael Zeiler¹, Gudrun Wagner¹
¹Medical University of Vienna, Department for Child and Adolescent Psychiatry, Eating Disorder Unit, Vienna, Austria, ²Institute of Psychiatry, Psychology & Neuroscience, Centre for Research in Eating and Weight Disorders, King's College London, London, United Kingdom

Introduction Anorexia nervosa (AN) in adolescence shows high chronicity and variable treatment responses. The adolescent version of the Maudsley Model of Anorexia Nervosa Treatment (MANTRa) has emerged as a promising alternative, but predictors of outcome remain unclear.
Methods This secondary analysis is based on a multi-center cohort study in Austrian clinical settings including 92 adolescents with AN (13-21 years) treated with MANTRa (n=45) or treatment-as-usual (TAU, n=47). Baseline predictors of outcome (change in eating disorder symptomatology) were analyzed at end-of-treatment and 18-month follow-up using univariate regression modes and cluster analyses (illness severity; motivation/personality profiles).
Results In the MANTRa group, none of the baseline variables significantly predicted outcome at 18-month follow-up. In TAU, higher initial eating disorder psychopathology and lower motivation were associated with poorer outcomes. Cluster analyses indicated sustained Improvement in MANTRa across different levels of illness severity and motivation/personality profiles. In TAU, sustained improvements were mainly observed in patients with lower illness severity and more favorable profiles, whereas those with higher severity and unfavorable profiles showed less benefit.
Conclusions Findings suggest that MANTRa may support symptom improvement across a broader range of patient characteristics compared to TAU. Further randomized controlled trials are needed to confirm these results.

P164

A Qualitative And Quantitative Analysis Of Impact Of Triangle Digital Platform Based Intervention On Children And Young People With Anorexia Nervosa And Their Carers.
Ashish Kumar², Gabriella Costain², Hubertus Himmerich¹, Janet Treasure¹
¹Kings College, London, United Kingdom, ²Mersey Care NHS Foundation NHS Trust, Liverpool, United Kingdom

Objective: To explore how young people with a diagnosis of Anorexia Nervosa and their carers describe shifts in understanding, thinking and perspective during a clinician moderated online forum group within a children’s eating disorder service. Methods: Verbatim transcripts from 6 cohorts of 7 consecutive online forum groups were analysed using reflexive thematic analysis. The discussions of 30 young people with a diagnosis of Anorexia Nervosa and 31 of their carers were analysed. The changes in wieght, height, vitals and outcome emasures were noted at start of the intervention and also at 3 monthly follow-up and quantitative analysis was conducted. Results: The qualitative analysis of transcripts from 6 cohorts of 7 concecutive sessions indicated that there were positive changes in thinking, feeling and behaviour reported by majority of children and young people and their parents and carers. The quantitiave analysis of completed measures such as EDE-Q, DASS, EDSIS, FQ indicated some change in pre-and post intervention. Conclusion:These findings suggest that digital group interventions can support recovery by facilitating shifts in cognitive, emotional and meaning based processes in young people and also in carers that may underpin change and motivation for recovery. The preliminary quantitative analysis indicates that there were changes in WFH/BMI and outcome measure output at follow-up at 3 months.

P165

Inpatient Re-Alimentation Of Patients With Anorexia Nervosa: Is There A Difference In Treatment Outcomes Between Flexitarians, Vegetarians And Vegans?
Anna Leiteritz, Wally Wuensch-Leitertiz
Klinik Lueneburger Heide, Bad Bevensen, Germany

Background: The prevalence of vegetarianism and veganism is increasing. However, it remains unclear whether and how effective re-alimentation of vegetarian and/or vegan patients with anorexia nervosa (AN) can be achieved. To our knowledge, there is currently no study that has systematically compared the effects of vegetarian or vegan versus flexitarian diets on clinical outcomes in patients with AN. Objective: The objective of this study is to compare three dietary groups of patients (flexitarian, vegetarian, vegan) with regard to differences in age, sex, comorbidities, medication, laboratory abnormalities, psychopathology, required energy intake during treatment, length of stay, and weight gain. Methods: We conducted a retrospective chart review of patients consecutively admitted to the Clinic Lueneburger Heide between January 1, 2019, and December 31, 2023 (n > 1000). Results and Conclusion: Efficient re-alimentation is possible in all three baseline dietary groups. A vegan diet does not preclude successful re-alimentation in patients with AN, although weight gain is slower, the length of inpatient stay is longer, and differences in energy and macronutrient composition in vegan diets require specific attention.

P166

Ketamine Assisted Psychotherapy For Eating Disorders &Ndash; A Retrospective Case Series
Camilla Lindvall Dahlgren¹, Lowan Stewart², Pål Sandvik², Ellie Bastos Degobi⁴
¹Department of Psychology, Oslo New Univeristy College, Oslo, Norway, ²Axon clinics, Oslo, Norway, ³Axon clinics, Oslo, Norway, ⁴Department of Psychology, São Francisco University, Campinas, Brazil

Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has demonstrated rapid antidepressant effects at sub-anesthetic doses and is increasingly explored for treatment-resistant psychiatric conditions, including eating disorders (EDs). Ketamine-assisted psychotherapy (KAP) combines ketamine administration with structured psychotherapy and may extend therapeutic effects by leveraging ketamine-induced neuroplasticity. Emerging evidence suggests KAP may reduce ED psychopathology and alleviate comorbid symptoms such as depression and anxiety. The objective of this study was to examine clinical change in a retrospective sample of patients with comorbid depression and EDs who received KAP. Routinely collected clinical data were extracted from patients treated at an outpatient clinic in Oslo, Norway. Preliminary analyses included 17 patients (16 female, 1 male; mean age 35.6) treated between 2023 and 2025. Participants sought treatment primarily for depression and had a current (n=16) or previous (n=1) ED diagnosis. Treatment consisted of 4-6 ketamine sessions combined with acceptance and commitment therapy. Preliminary analyses indicated significant improvements across all outcomes, with medium to large effect sizes for reductions in depressive symptoms, anxiety, and ED psychopathology, alongside increased psychological flexibility. These findings suggest KAP may represent a promising treatment approach for individuals with comorbid depression and eating disorders

P167

How Do Adolescents And Young Adults With Binge Eating Fare On Glp-1 Medications? A Qualitative Examination Of Patients And Caregivers.
Stephanie M Manasse¹, Isabella Pruscino¹, Evan M Forman², Adrienne S Juarascio³, Isa Granados⁴, Thao-Ly Phan¹
¹Nemours Children's Health, Wilmington, DE, United States, ²Thomas Jefferson University, Philaelphia, PA, United States, ³Oregon Research Institute, Springfield, OR, United States, ⁴Nemours Children's Health, Jacksonville, FL, United States

Introduction. Adolescents and young adults (AYA) with binge eating (BE) and obesity frequently present to weight management settings and are increasingly prescribed GLP-1 medications despite limited data on impacts. Understanding AYA and parent experiences with GLP-1s is necessary to improve clinical guidance. Methods. We recruited AYA (ages 12-20) with current or past BE and their caregivers (n=5; anticipated n=10) who were patients in a pediatric weight management clinic and had experience taking GLP-1s to complete separate qualitative interviews regarding their perspectives on these medications. Results. Initial analysis revealed the following themes from AYAs and caregivers: (1) despite high variability in reported weight loss, GLP-1s were generally reported as more effective for weight loss than other methods previously tried; (2) BE was partially reduced while on GLP-1s, which was attributed by AYA and caregivers to better satiety signaling and less food noise; (3) frequent problems with side effects (possibly related to continued BE and/or diet choices) and insurance coverage sometimes led to discontinuation; and (4) all AYAs and caregivers denied any harmful effects with regards to eating pathology and weight stigma. Conclusion. Most AYAs and caregivers were satisfied with GLP-1 effects, but continued BE was present and side effects were common. Future research should continue to evaluate the positive and possible iatrogenic effects of GLP-1s for AYAs with BE.

P168

Bodyscreen: A Pilot Evaluation Of A Mobile App Intervention Targeting Social Media Engagement And Eating Disorder Risk In Adolescents And Young Adults
Louise Mason¹, Victoria Yarmey¹, Shuya Li², Mohamed Muzamil¹, Sumit Kumar¹, Simon B. Sherry^1,2, Emilie Lacroix³, Jennifer S. Mills⁴, Aaron Keshen^1,5, Sandra M. Meier⁶
¹Department of Psychiatry, Dalhousie University, Halifax, NS, Canada, ²Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada, ³Department of Psychology, University of New Brunswick, Fredericton, NB, Canada, ⁴Department of Psychology, York University, Toronto, ON, Canada, ⁵Nova Scotia Health, Halifax, NS, Canada, ⁶IWK Health Centre, Halifax, NS, Canada

Objectives: Appearance-focused social media use contributes to body dissatisfaction and elevated eating disorder (ED) risk in adolescents and young adults. This pilot trial evaluated BodyScreen, a 4-week mobile app designed to reduce maladaptive social media engagement and ED risk. Methods: 80 young women with elevated ED risk participated in a single-arm pilot trial. Assessments were conducted pre- and post-intervention. Outcomes included ED symptomatology, body dissatisfaction, self-esteem, perfectionism, social media use, psychological adjustment, and quality of life. Results: 68 participants (85%) completed post-intervention assessments. ED symptoms decreased significantly (M = 47.92 → 38.01; b = −9.91, 95% CI [−12.92, −6.90], p <.001; d = −1.12 ). Improvements were also observed across body dissatisfaction (d = −1.30), self-esteem (d = 0.84), perfectionism (d = −0.85), social media use (d = −0.46), psychological maladjustment (d = −1.30), and quality of life (d = 0.50). Engagement was high (73% completing ≥70% of exercises) and few negative effects were reported, while usability was moderate. Qualitative feedback highlighted structured daily routines and skill acquisition as facilitators, with repetitive self-monitoring and minor interface challenges as barriers. Conclusions: BodyScreen is a feasible and promising early intervention for young women at elevated ED risk, particularly those with appearance-focused social media use.

P169

Virtual Reality Food Exposure In Patients With Anorexia Nervosa: A Pilot Randomized-Controlled Trial
Valentina Meregalli, Chiara Tosi, Ludovica Natali, Valentina Cardi
University of Padova, Padova, Italy

Introduction: Anorexia nervosa (AN) is characterized by intense anxiety and aversive responses to food stimuli, contributing to the maintenance of restrictive behaviors. Virtual reality (VR) may offer a controlled environment for graduated food exposure, bypassing barriers of in-vivo approaches. Methods: 74 patients with AN receiving standard treatment from Italian daycare services were randomized to VR exposure to a kitchen (TAU + foodVR n=24), VR exposure to a natural relaxing scenario (TAU+natureVR n=22), or no VR exposure (TAU only, n=28) on five consecutive days. State anxiety (STAI), positive and negative affect (PANAS), meal-related anxiety, and food evaluations (wanting, liking, fear) were assessed pre- and post-intervention. Results: No significant changes in anxiety or affect were observed across groups. Food wanting increased for medium- and high-calorie foods and decreased for low-calorie foods in all groups, regardless of condition. For food liking, a three-way interaction (time × calorie content × group) was observed: ratings for high- and medium-calorie foods increased in both VR groups, whereas a decreasing trend was found in TAU. Conclusions: Both VR protocols increased liking for high- and medium-calorie foods, suggesting a general effect of VR exposure, possibly mediated by anxiety reduction or positive affect induction. These findings support VR as a promising adjunct to standard treatment in AN to foster more positive food evaluations.

P170

Beyond Weight Loss: One-Year Binge Eating Behavior And Mental Health Outcomes With Liraglutide, A Glp-1 Receptor Agonist
Maria F. Moreira^1,2, Isadora Carneiro², Walter S. Gonçalves¹, Livia Lugarinho², Priscila Alves², Silvia R. Freitas², Jose C. Appolinario^1,2
¹Group of Obesity and Eating Disorders (GOTA) from the Institute of Psychiatry from the Federal university of Rio de Janeiro, Rio de Janeiro, Brazil, ²Institute of Diabetes and Endocrinology of Rio de Janeiro, Rio de JAneiro, Brazil

Introduction: Despite the increasing use of GLP-1 receptor agonists, prospective data on their impact on eating behavior and mental health remain limited. This study aimed to evaluate the effects of liraglutide on these outcomes, and the influence of preexisting significant binge eating (BE) and psychiatric disorders on weight loss. Methods: This longitudinal, open-label study included 23 patients with BMI >45 kg/m² from a tertiary obesity center. The target dose titration for Liraglutide was 3.0 mg. Assessments were conducted at baseline and at 4 visits over one year. Eating behavior was assessed using the Binge Eating Scale (BES), and mental health using the MINI and the Hospital Anxiety and Depression Scale. Data were analyzed using Generalized Estimating Equations (GEE). Results: Participants were predominantly female (82.6%), mean age of 49.3 years and mean BMI of 55.6 kg/m². Overall, 47.2% (n=11) had mild-to-moderate BE (BES >17), and 52.1% (n=12) had at least one psychiatric diagnosis. GEE analyses showed significant reductions in anxiety (B=2.341; SE=0.5; p<0.001) and BE symptoms (B=2.677; SE=2.6; p=0.009), with no significant changes in depressive symptoms (B=3.272; SE=0.8; p=0.8). Baseline BE and psychiatric disorders did not significantly affect weight loss outcomes (time × BES>17 p=0.26; time × psychiatric diagnosis p=0.34). Conclusion: Liraglutide reduced anxiety and BE symptons, without impact of baseline psychiatric disorders and binge eating on weight loss in our sample.

P171

Family-Based Treatment For Anorexia Nervosa: Lived Experience And Clinician Opinions Between Nations (Falcon)
Erica Neill^{1, 2}, Shannon Calvert³, Kamryn T Eddy^{4, 5}, Claire Finkelstein⁶, Alexandra McCord^{7, 8}, Steph Miles^{1, 2, 6}, Genevieve Pepin⁹, Jennifer J Thomas^{4, 5}, Andrea Phillipou^{1, 2, 6}
¹Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Victoria, Australia, Melbourne, Australia, ²Centre for Youth Mental Health, The University of Melbourne, Melbourne, Victoria, Australia, Melbourne, Australia, ³National Eating Disorders Collaboration, Melbourne, Victoria, Australia, Melbourne, Australia, ⁴Eating Disorders Clinical and Research Program, Massachusetts General Hospital, Boston, Massachusetts, USA, Boston, MA, United States, ⁵Department of Psychiatry, Harvard Medical School, Boston, Massachusetts, USA, Boston, MA, United States, ⁶Department of Psychological Sciences, Swinburne University of Technology, Melbourne, Victoria, Australia, Melbourne , Australia, ⁷School of Psychology, University of New England, New South Wales, Australia, Armidale , Australia, ⁸Child and Adolescent Specialist Eating Disorder Service, New South Wales Health, Australia, Ewingdale, Australia, ⁹School of Health and Social Development-Occupational Therapy, Deakin University, Geelong, Victoria, Australia, Geelong, Australia

Introduction: Family-based treatment (FBT) is the first-line treatment for individuals aged <18 with anorexia nervosa (AN) in both Australia and the United States (US), despite recipients reporting both positive and negative experiences. Given its variable impact on patients and families, identifying ways to improve the treatment experience is essential. In Australia, negative experiences of FBT have been reported by patients, carers, and clinicians. This contrasts with reports suggesting greater acceptability in the US; however, no direct cross-country comparisons have been conducted. This survey aims to (1) examine whether FBT is more acceptable in the US than in Australia and (2) identify factors within and across countries that influence experiences of receiving or delivering FBT. Methods: This anonymous cross-sectional online survey will recruit patients and carers who have undergone FBT, as well as clinicians who have delivered it, in Australia or the US. Results: Findings will determine whether acceptability differs between countries and, if so, identify factors contributing to these differences, including whether sociodemographic and cultural differences contribute. Preliminary findings will be presented Conclusions: This study addresses an important gap in the literature and may inform FBT service delivery, particularly improving its fit for the Australian context.

P172

Beyond Weight Restoration: Dietary Variety And Psychosocial Functioning Following Family-Based Treatment For Avoidant/Restrictive Food Intake Disorder In Children
Megan M. Ruiz Fischer, Brittany E. Matheson, HaLi Boyce, Ainsley E. Cogburn, Qianheng Ma, James D. Lock
Stanford University School of Medicine , Palo Alto, CA, United States

Objective: This secondary analysis examined changes in dietary variety from a randomized clinical trial comparing Family-Based Treatment (FBT) and Psychoeducational Motivation Therapy (PMT) for underweight children with avoidant-restrictive food intake disorder (ARFID) where FBT was superior in promoting weight gain. Increased dietary variety may be a related clinical outcome, particularly for children with sensory sensitivities. We hypothesized a significantly greater increase in dietary variety from baseline (BL) to end-of-treatment (EOT) in children randomized to FBT. Method: Participants were N = 98 underweight (M = 84.6, SD = 4.6 %EBW) children aged 6 to 12 years (M = 9.72, SD = 1.96; 41% female; 20% Hispanic) recruited nationwide (US) between April 2021 and July 2025 with a diagnosis of ARFID. Participants were randomized to receive either FBT (n = 49) or PMT (n = 49). Data from items on a diagnostic and symptom severity measure (Pica, ARFID, and Rumination Disorder Interview; PARDI) were evaluated at BL and EOT using non-parametric approaches. Results: Preliminary results indicated a significant increase in dietary variety from BL to EOT (p<.001, r = .571) for FBT but not for PMT (p=.335, r = .137). Conclusions: Findings suggest that FBT significantly increases dietary variety in underweight children with ARFID compared to PMT. This aligns with greater weight gain in the FBT group and supports the use of FBT for children with limited dietary variety.

P173

Comparative Efficacy And Acceptability Of Interventions For Universal, Selective, And Indicated Prevention Of Eating Disorders: A Systematic Review And Network Meta-Analysis
Sandra Schlegl^{1, 2}, Felicitas Hirler¹, Andreas Gerich¹, Mikkel Højlund³, Eric Stice⁴, Tracey Wade⁵, Denise Wilfley⁶, James Downs⁷, Ulrich Voderholzer^{1, 8, 9}, Jasmine Perry⁴, Verena Haas¹⁰, Marco Solmi^{11, 12, 13}, Christoph Correll^{10, 14, 15}
¹Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany, ²Department of Clinical Psychology and Experimental Psychopathology, Goethe University Frankfurt am Main, Frankfurt am Main, Germany, ³Department of Regional Health Research, University of Southern Denmark, Aabenraa, Denmark, ⁴Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States, ⁵Institute for Mental Health and Wellbeing, Flinders University, Adelaide, Australia, ⁶Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, United States, ⁷Independent Researcher and Expert by Experience, Cardiff, United Kingdom, ⁸Department of Psychiatry and Psychotherapy, University Hospital of Freiburg, Freiburg, Germany, ⁹Schoen Clinic Roseneck, Prien am Chiemsee, Germany, ¹⁰Department of Child and Adolescent Psychiatry, corporate member of Freie, Charité Universitätsmedizin Berlin, Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany, ¹¹SCIENCES Lab, Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada, ¹²Regional Centre for the Treatment of Eating Disorders and On Track, The Champlain First Episode Psychosis Program, Department of Mental Health, The Ottawa Hospital, Ottawa, ON, Canada, ¹³Clinical Epidemiology Program, Ottawa Hospital Research Institute (OHRI), University of Ottawa, Ottawa, ON, Canada, ¹⁴Department of Psychiatry Research, The Zucker Hillside Hospital, New York City, NY, United States, ¹⁵Department of Psychiatry and Molecular Medicine, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States

1. Introduction: Eating disorders (EDs) are severe psychiatric conditions with substantial prevalence, chronicity, and mortality, underscoring the need for effective prevention. An inclusive systematic review and network meta-analysis (NMA) comparing efficacy and acceptability of universal, selective, and indicated preventive interventions is missing. 2. Methods: Randomized controlled trials were identified through searches in MEDLINE, Embase, PsycINFO, and CENTRAL. Eligible interventions included psychological, educational, physical, and nutritional approaches targeting ED prevention, disordered eating, body image distortion, or related risk factors. Co-primary outcomes are ED diagnostic symptoms, overall ED pathology, ED onset, and all-cause discontinuation. Separate frequentist network meta-analyses will be conducted by prevention type. Bias is assessed with the RoB 2. 3. Results: To date, 4,789 records have been screened, and 827 full-text articles assessed. Preliminary eligibility assessment identified 47 RCTs on universal, 183 on selective, and 16 on indicated prevention. Data extraction has been completed for 200 studies and independently cross-checked. After updating the search, final results of the NMA comparing efficacy and acceptability of the interventions will be presented at the meeting. 4. Conclusion: This NMA will address limitations of previous evidence syntheses and provide comparative evidence to guide tailored prevention strategies for different risk groups.

P174

Do Adolescent, Parent, And Dyadic Behaviors During The Family Meal Predict Response To Family-Based Treatment For Anorexia Nervosa?
Simar Singh¹, Catherine R. Drury^1,2, Sasha Gorrell¹, Brittany E. Matheson³, Naomi Lynch^1,4, HaLi Boyce³, Sapna Ramappa⁵, Ainsley Cogburn³, Hazal Gurcan^3,6, Marina Pouliadi^3,7, Solveig Behr^3,8, James D. Lock³, Daniel Le Grange^1,9
¹Department of Psychiatry & Behavioral Sciences University of California, San Francisco, CA, United States, ²Department of Psychiatry & Behavioral Sciences Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY, United States, ³Department of Psychiatry & Behavioral Sciences Stanford University, Palo Alto, CA, United States, ⁴School of Engineering University of Pennsylvania, Philadelphia, PA, United States, ⁵School of Medicine University of California, San Francisco, San Francisco, CA, United States, ⁶Bloomberg School of Public Health Johns Hopkins University, Baltimore, MD, United States, ⁷North London NHS Foundation Trust, London, United Kingdom, ⁸Freie Universität, Berlin, Germany, ⁹Department of Psychiatry and Behavioral Sciences The University of Chicago, Chicago, IL, United States

Objective: In family-based treatment (FBT), patient and caregiver behavior during the family meal (FM) session predict end-of-treatment (EOT) outcomes. Intensive parental coaching (IPC) for early non-responders (<2.4kg gain by Session 4) includes a second FM. It is unclear whether FM2 behaviors also predict outcomes. Methods: FM session videos from an FBT trial (N=83) were coded and analyzed. Early non-responders were randomized to FBT or FBT+IPC. Binomial logistic regression tested whether FM1 behavior predicted early response. Lag sequential analyses explored which FM1 dyadic pairs predicted early response. Among non-responders randomized to IPC (n=17), stepwise linear regressions tested if change in behavior from FM1 to FM2 predicted psychological and weight outcomes. Results: In FM1, greater youth restriction (OR=1.06, p=.034) and negative affect (OR=1.10, p=.043), and lesser parent modeling eating (OR=.97, p=.025) predicted higher odds of early non-response. Across FM1 dyads, youth not eating followed by parent eating predicted higher odds of early response (OR=.20, p=.003). For non-responders in IPC, increases in youths’ meal arrangement and negative affect, decreases in parents’ meal presentation and modeling eating, and increases in parents’ verbal criticism and conflict, from FM1 to FM2 predicted worse psychological and weight outcomes (all ps<.030). Discussion: FM behaviors predict early and EOT outcomes in FBT, offering malleable targets for therapist coaching.

P175

Effects Of A Dissonance-Based Eating Disorder Prevention Program For Women With Type 1 Diabetes At 2-Year Follow-Up: A Randomized Trial
Eric Stice¹, Line Wisting², Maartje de Wit³, Elena Toschi⁴, Nicole Dunkel¹
¹Stanford University, Stanford, CA, United States, ²Oslo University Hospital, Oslo, Norway, ³Amsterdam University Medical Center, Amsterdam, Netherlands, ⁴Joslin Diabetes Center, Boston, MA, United States

Objective: Evaluate whether the dissonance-based Diabetes Body Project prevention program reduces eating disorder (ED) risk factors and symptoms among women with type 1 diabetes, who are at elevated risk for eating pathology. Methods: Young women (aged 15-30) with type 1 diabetes and body image concerns (N = 293) were randomized to virtually delivered Diabetes Body Project groups or an educational video control condition, completing measures at pretest, posttest, 1-year follow-up, and 2-year follow-up. Results: We are still currently analyzing the 2-year follow-up results. Conclusions: We anticipate that, like with the 1-year follow-up data, virtually delivered Diabetes Body Project decreased eating disorder risk factors and symptoms in young women with type 1 diabetes, suggesting it would be useful to implement this eating disorder prevention program for this unique population at ultra-high-risk for eating pathology.

P176

Development And Feasibility Pilot Of Integrative Cognitive Affective Therapy &Ndash; Brief (Icat-Brief) For Bulimia Nervosa: A Case Series
Ana Vaz^1,2, Rita Ramos³, António Neves^1,2, Carol Coelho³, Carol Peterson⁵, Steve Wonderlich⁴, Paulo Machado³
¹Faculty of Medicine, University of Lisbon, Lisboa, Portugal, ²Eating Disorders Unit, Hospital de Santa Maria, Lisboa, Portugal, ³School of Psychology, University of Minho, Braga, Portugal, ⁴University of North Dakota School of Medicine and Health Sciences, Fargo, ND, United States, ⁵University of Minnesota Medical School, Minneapolis, MN, United States

Integrative Cognitive Affective Therapy (ICAT) is a 21-session evidence-based treatment for bulimia nervosa (BN) targeting momentary affective dysregulation, maladaptive cognitions, and disordered eating. However, there is growing evidence supporting briefer interventions to improve treatment accessibility in resource-constrained settings. The current study aims to develop a theory-informed adaptation and manual refinement of the ICAT-Brief for BN and to conduct a feasibility case series evaluation. After a systematic review of the ICAT evidence base, explicit articulation of the theory of change, and iterative expert manual refinement, core components of the manual were preserved in a 10-session format. The preliminary short version of the manual was pilot-tested with adults meeting DSM-5-TR criteria for BN at a specialized eating disorders hospital unit in Portugal, examining acceptability, retention, and clinical outcomes. Data from the current 5 completed cases demonstrate significant improvements in binge and purge frequency, ED attitudes, and emotion dysregulation, alongside high treatment acceptability with a brief version of the ICAT. Session-by-session trajectories and individual case profiles will be presented. We expect 10+ cases to be completed prior to the conference. Preliminary findings suggest that ICAT's active mechanisms can be delivered effectively in a briefer format, with implications for accessibility and dissemination in routine clinical settings.

P177

Impact Of Training On Clinicians&Rsquo; Confidence And Perceived Competence When Learning A New Therapy Protocol For Anorexia Nervosa
Glenn Waller^1,2, Jessica Beard², Hannah Turner³
¹University of Warwick, Coventry, United Kingdom, ²University of Sheffield, Sheffield, United Kingdom, ³Hampshire and Isle of Wight NHS Foundation Trust, Southampton, United Kingdom

Introduction: This study assessed the impact of training in a new brief cognitive-behavioural therapy for anorexia nervosa, in order to determine whether: Confidence and perceived competence were enhanced by training; Any demographic/professional characteristics influenced the impact of the training. Method: The study used a pre-post design, with confidence and competence compared before and after a two-day skills-based training in CBT-AN-20. The sample were 154 clinicians (age 23-68; 92% female; 1-27 years experience) from different professions working with eating disorders. Each completed the initial. Completer and intention-to-treat analyses were used to compare pre-post ratings, along with multiple regressions to determine impact of clinician characteristics. Results: Clinician confidence in their ability to deliver CBT for anorexia nervosa improved substantially following the training (fairly-entirely confident rising from 57% to 91%). Modal confidence rose from ‘fairly’ to ‘very’ for all individual CBT-AN-20 skills. However, no clinician characteristics (e.g., profession, age) influenced outcome. Post-training, 73% stated an intention to begin using CBT-AN-20. Conclusions: Skills-based training in CBT-AN-20 is effective at enhancing confidence and perceived competence to deliver the therapy, among a wide range of professionals working with anorexia nervosa sufferers. Further research is needed to determine how that learning manifests in the delivery of CBT-AN-20 itself.

P178

Does Occupational Therapy Have A Role In Innovative Eating Disorder Treatment? A Scoping Review Of The Literature
Rebecca L. Willman¹, Kelly Farrell², Caroline Stanton³, Maddie Duzyk⁴
¹Department of Occupational Therapy, Colorado State University, Fort Collins, CO, United States, ²Department of Rehabilitation, Exercise & Nutrition Sciences, University of Cincinnati, Cincinnati, OH, United States, ³Prisma Health Children’s Hospital, Greenville, SC, United States, ⁴Positive OT Practice LLC, Fort Mitchell, KY, United States

Introduction: Occupational therapy (OT) practitioners use meaningful daily activities (i.e., occupations) to uniquely contribute to interprofessional eating disorder (ED) treatment. However, the scope and nature of OT in this context remain unclear. This study seeks to identify and describe the role of OT in ED treatment and map existing literature to the OT Domain and Practice Framework (OTPF-4). Methods: We will conduct a scoping review of literature on OT in the treatment of diagnosed EDs in four databases: CINAHL, PsycINFO, PubMed, and Web of Science. Select sources of grey literature will be included. Searches will be limited to English language with no restrictions on age, study design, setting, or geographic location. Quantitative data will be analyzed using descriptive statistics and qualitative data will be analyzed using deductive content analysis informed by the OTPF-4. Results: Initial database searches brought forth 199 results from CINAHL, 229 from PsycINFO, 108 from PubMed, and 138 from Web of Science. Full-text articles for inclusion in our analysis will be selected and preliminary findings will be available at the time of presentation. Discussion: OT practitioners comprehensively address person, environment, and occupation factors. To our knowledge, this will be the first scoping review to map literature to the OTPF-4, which will inform clinical applications, future research directions, and clarification and advancement of the role of OT in interprofessional ED treatment.

P179

Changing Habits In Anorexia Nervosa - A Randomized Controlled Trial
Eva D. Zielke-Rössel¹, Deborah R. Glasofer², Joanna E. Steinglass², Marielaura Hörning-Suermann¹, York Hagmayer¹, Wally Wünsch-Leiteritz³, Timo Brockmeyer^1,4
¹Department of Clinical Psychology and Psychotherapy, Institute for Psychology, University of Göttingen, Göttingen, Germany, ²Department of Psychiatry, Center for Eating Disorders, New York State Psychiatric Institute, Columbia University Medical Center, New York, NY, United States, ³Klinik Lüneburger Heide, Bad Bevensen, Germany, ⁴Clinical Psychology and Translational Psychotherapy Unit, Institute of Psychology, University of Münster, Münster, Germany

Background: Habitual eating- and weight-related behaviors are considered maintaining mechanisms in anorexia nervosa (AN). Regulating Emotions and Changing Habits (REaCH) is a behavioral intervention that targets such maladaptive habits and emotion regulation. Building on encouraging findings from a pilot trial, this study provides the first fully powered evaluation of REaCH. Methods: In this randomized controlled trial, 110 inpatients with AN were randomly assigned (1:1) to 12 sessions of REaCH (n=53) or supportive psychotherapy (SPT; n=57) in addition to standard inpatient care. The primary outcome was change in body mass index (BMI) from baseline to 6-month follow-up. Secondary outcomes were changes in BMI, eating disorder psychopathology, habit strength, and emotion regulation difficulties from baseline to end of treatment and follow-up, and food choice from baseline to end of treatment. Analyses used intention-to-treat multilevel models. Results: REaCH was not superior to SPT for BMI change at 6-month follow-up. No group differences were found for secondary outcomes. Across treatments, participants improved significantly in BMI, eating disorder psychopathology, habit strength, and emotion regulation difficulties. Food choice did not change. Conclusions: REaCH was not superior to SPT in this inpatient sample. Habit-focused interventions may not add benefit over supportive treatment in intensive inpatient settings. Future research should test effects in other settings or subgroups.

9:00

Biomarkers For Anorexia Nervosa
Hubertus Himmerich
King's College London

P1
10:00

Rethinking Eating Disorders: Bold New Targets, Treatments, And Technologies
Aaron Keshen
Dalhousie University/Nova Scotia Health

P2
10:20

Brain Energy Metabolism As A Transdiagnostic Treatment Target In Eating Disorders
Guido Frank
University of California

P3
10:40

Neuromodulation In Eating Disorders
D. Blake Woodside
University of Toronto

P4
11:00

Translational Science To Develop Mechanism Based Pharmacotherapy For Anorexia Nervosa
Joanna Steinglass
Columbia University/New York State Psychiatric Institute

1:15

The Clinical Efficacy Of Probiotic Administration Compared To Placebo In Adolescents With Anorexia Nervosa: A Randomized Controlled Trial
Michael Zeiler¹, Nadia Andrea Andreani^2,3, Kathrin Kollndorfer⁴, Konstantin Kopp¹, Julia Klang¹, Florian Ph. S. Fischmeister⁴, Gudrun Wagner¹, Kathrin Sevecke⁵, Lara Keller^6,7, Astrid Dempfle⁸, John Baines², Jochen Seitz⁷, Beate Herpertz-Dahlmann⁶, Andreas Karwautz¹
¹Eating Disorders Care & Research Unit, Department for Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria, ²Institute for Experimental Medicine, Max Planck Institute for Evolutionary Biology, Kiel University, Plön, Germany, ³Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy, ⁴Developmental and Interventional Neuroimaging Lab, Department of Biomedical Imaging and Image‐guided Therapy, Medical University of Vienna, Vienna, Austria, ⁵Department of Child and Adolescent Psychiatry, Medical University of Innsbruck, Innsbruck, Austria, ⁶Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital RWTH Aachen, Aachen, Austria, ⁷Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, LVR University Hospital Essen, Essen, Germany, ⁸Institute of Medical Informatics and Statistics, Kiel University, Kiel, Germany

Objectives: The aim of the present study was to examine the efficacy of probiotics in patients with anorexia nervosa (AN) on psychopathology and gut microbiome outcomes. Methods: We conducted a double-blind randomized-controlled trial with female adolescent inpatients with AN who received either multistrain probiotics (Lactobacillus, Bifidobacterium) (n=37) or placebo (n=35) for six months. Outcomes were measured at discharge, end-of-treatment and 12-month follow-up, including BMI standard deviation score (SDS) as the primary outcome as well as AN and comorbid psychopathology, gastrointestinal symptoms, gut microbiome richness (alpha-diversity) and composition (beta-diversity) as secondary outcomes. Results: Multilinear mixed models revealed no statistically significant differences between the probiotic and placebo groups for BMI-SDS (p=.580), AN psychopathology, depressive, obsessive-compulsive and gastrointestinal symptoms at the 12-month primary endpoint or at earlier time points. Moreover, probiotic supplementation did not alter gut microbiome alpha-diversity and beta-diversity compared to the placebo group. Conclusion: There is currently no evidence for the efficacy of probiotics beyond standard treatment. Future studies should examine their potential therapeutic effects for patients with severe gastrointestinal symptoms or in a heightened inflammatory state. Moreover, more in-depth microbial analysis, such as ongoing shotgun metagenomic sequencing or metabolomic approaches are needed.

2:30

Restoring Reward In Recovery: A Randomized, Controlled Trial Of Positive Affect Treatment For Post-Acute Anorexia Nervosa
Ann F. Haynos^1,2, Olivia Chapman¹, Lisa M. Anderson², Michelle G. Craske^3,4, Carol B. Peterson²
¹Virginia Commonwealth University, Department of Psychology, Richmond, VA, United States, ²University of Minnesota, Department of Psychiatry and Behavioral Sciences, Minneapolis, MN, United States, ³University of California, Los Angeles, Department of Psychology, Los Angeles, CA, United States, ⁴University of California, Los Angeles, Department of Psychiatry & Biobehavioral Sciences, Los Angeles, CA, United States

Introduction: Anorexia nervosa (AN) is associated with reward anomalies. Standard AN treatments do not target reward processes, which may limit acceptability, efficacy, and comorbidity targeting. We adapted Positive Affect Treatment (PAT), a novel therapy targeting transdiagnostic reward deficits, for AN and tested its impact in the high-risk “post-acute” period after intensive treatment. Methods: Participants with post-acute AN/atypical AN (N=68) were randomized to 24 weeks of PAT or psychoeducation and behavior therapy (PBT; a CBT-based eating disorder [ED] treatment). ED, psychological, and reward measure changes were examined at baseline, mid-treatment, end of treatment (EOT), and 3-month follow-up (FU). Results: Both treatments supported weight maintenance (p=.658) and reduced ED symptoms (p<.001). PBT yielded faster ED symptom change by mid-treatment (p=.035), but did not differ from PAT at EOT or FU (ps>.336). PAT was rated more acceptable (p=.011) and produced more mood, suicidality, and quality-of-life improvement (ps<.020). Patients with severe mood pathology or lower reward anticipation had more ED change (ps<.025) in PAT vs. PBT. Conclusion: New AN treatments are sorely needed and PAT shows therapeutic promise, especially for patients with reward deficits. PAT holds advantage over traditional ED treatment in acceptability, broad psychological benefits, and reduced suicidality, yet may benefit from incorporating standard ED interventions to yield faster ED change.

1:00

Feasibility, Acceptability, And Outcomes Of Group Cbt-T: A Naturalistic Mixed-Methods Comparison With Individual Cbt-T
Laura Dixon¹, Anastasia Harris¹, Victoria Taylor¹, Lily Spoozak¹, Sara Bartel¹, Susan Gamberg^1,2, Nami Trappenberg¹, Colby Price¹, Navjot Sandila³, Elena Koning², Sarrah I. Ali⁴, Erin Piercy¹, Glenn Waller⁵, Aaron Keshen^1,2
¹Nova Scotia Provincial Eating Disorder Service, Nova Scotia Health, Halifax, NS, Canada, ²Department of Psychiatry, Dalhousie University, Halifax, NS, Canada, ³Research Methods Unit, Nova Scotia Health, Halifax, NS, Canada, ⁴Department of Psychology, Florida State University, Tallahassee, FL, United States, ⁵Department of Psychology, University of Warwick, Coventry, United Kingdom

Introduction: This study evaluated the feasibility of implementing 10-session group cognitive behavioral therapy (CBT-Tg) in a routine outpatient eating disorder (ED) clinic and descriptively compared outcomes with individual CBT-T (CBT-Ti). Method: Using a naturalistic, non-randomized, mixed-methods design, adults with non-underweight EDs selected CBT-Tg or CBT-Ti after intake. Feasibility outcomes included acceptability (satisfaction, qualitative interviews, dropout), demand (uptake over time), and practicality (clinician time). Effectiveness outcomes included ED psychopathology measured by the Eating Disorder Examination Questionnaire (EDE-Q) and secondary measures of symptoms, impairment, and mood/anxiety through 6-month follow-up. Results: Of 157 referred patients, 116 initiated treatment. Satisfaction was high and similar across formats. Premature termination from CBT-Tg was 44.7%. Demand supported CBT-Tg delivery in 8 of 9 three-month intervals. Clinician time was 4.3-5.7 hours per patient for CBT-Tg versus 8.0 for CBT-Ti. EDE-Q global scores improved with very large within-group effects at end of therapy, maintained at 6-month follow-up (CBT-Tg: g = −1.57, −1.63; CBT-Ti: g = −1.97, −2.14). Conclusion: CBT-Tg is feasible and acceptable in real-world outpatient care, with large, sustained improvements in ED psychopathology and efficiency advantages over individual delivery, supporting further comparative and cost-effectiveness research.

1:30

Wearable-Based Activity Monitoring And Therapeutic Feedback For Movement Regulation In Inpatients With Anorexia Nervosa: A Controlled Feasibility Pilot Study
Michael Hollauf^1,2,3, Christian Fricke¹, Claudia Mönch¹, Alexander Heimbeck¹, Sandra Konik³, Ulrich Cuntz^1,2, Ulrich Voderholzer^1,4,5
¹Schön Klinik Roseneck, Prien am Chiemsee, Germany, ²Paracelsus Medical University, Salzburg, Austria, ³ Department for Health Sciences, Medicine and Research, University for Continuing Education Krems, Krems an der Donau, Austria, ⁴Department of Psychiatry and Psychotherapy, LMU University Medicine, Munich, Germany, ⁵Department of Psychiatry and Psychotherapy, Albert-Ludwigs-University Freiburg, Freiburg, Germany

Introduction: Compulsive exercise is common in anorexia nervosa (AN), difficult to regulate during treatment, and linked to poorer outcomes and relapse risk. Objective activity data rarely inform therapeutic feedback. This pilot is the first empirical step of HIET (Health Intensity Exercise Transfer), a translational intervention and research framework using wearable-based feedback to support movement regulation in AN. Methods: We conducted a controlled feasibility pilot in an inpatient AN setting. Patients with AN completed eight sessions of a manual-based group intervention. The intervention group (IG;n=13) wore Polar Unite watches and Movisens Move 4 sensors, with Polar-derived data used for structured feedback twice weekly. Controls (n=12) wore Movisens Move 4 sensors only and received the intervention without feedback. Feasibility, BMI, Commitment to Exercise Scale (CES), and activity parameters were examined. Results: Monitoring and feedback were feasible and well accepted, with high wear-time adherence in the IG. CES scores decreased over time (p<.001), with larger exploratory reductions in the IG (d=1.26) vs controls (d=0.57). Activity parameters showed heterogeneous signals. BMI increased over time (p<.001; IG d=-0.65, controls d=-0.27), consistent with weight-restoration goals. Conclusions: Wearable monitoring and feedback appear feasible for movement regulation in inpatient AN treatment. This pilot supports further wearable/sensor validation and scaled efficacy evaluation within HIET.

2:00

Care-By-Claire: Addressing Eating Disorders And Symptoms Of Burnout And Stress With An App-Based Program-Guided Digital Cbt For Patients With Eating Disorders. A Real-World Study
Klara Edlund¹, Niklas Forsberg², Solfrid Bratland-Sanda³, Ata Ghaderi¹
¹Karolinska Institutet, Stockholm, Sweden, ²University of Gothenburg, Gothenburg, Sweden, ³University of South-East Norway, Notodden, Norway

Introduction: More digital solutions for accessible, tailored treatments for eating disorders (ED) are needed. This study assessed the feasibility and preliminary effect of a CBT-based app for reducing symptoms of ED and burnout. Methods: Ninety patients (age 14–47) were enrolled in a 12-step, 12-week intervention delivered via the Claire app (App Store/Google Play). Assessments pre-, mid-, and post-treatment (tx) included Clinical Impairment Assessment (CIA), Eating Disorders Examination-Q (EDE-Q), Shirom-Melamed Burnout-Q (SMBQ), and Depression, Anxiety and Stress Scale (DASS). A within-subject design was used; 66 completed (n=14 still in tx, n=10 drop-outs) with Linear mixed-effects models and estimated effects (Cohen’s d). Results: Linear mixed-effects models showed improvements across all outcomes (p <0.001). CIA showed a substantial reduction [Mdiff = -15.96; d = 2.46, 95% CI (2.06, 2.86)] post-tx. Large effects were also observed for burnout [SMBQ: d = 1.73, 95% CI (1.34, 2.11)], ED pathology [EDE-Q: d = 1.54 (1.18, 1.91)], and stress [DASS: d = 1.70 (1.33, 2.07)]. Conclusions: Findings suggest app-based treatment can reduce ED and stress-related symptoms, supporting scalable, technology-driven care. Controlled studies with follow-up are needed.

2:15

Ecological Momentary Interventions In The Management Of Eating Disorders And Obesity: A Systematic Review
Wenlu Mao¹, Ricarda Schmidt², Emily K. Presseller³, Adrienne Juarascio⁴, Anja Hilbert¹
¹Behavioral Medicine Research Unit, Department of Psychosomatic Medicine and Psychotherapy, University Medical Center Leipzig, Leipzig, Germany, ²Department of Child and Adolescent Psychiatry, Psychotherapy and Psychosomatics, University Hospital Leipzig, Leipzig, Germany, ³Department of Biomedical Data Science and Department of Psychiatry, Geisel School of Medicine at Dartmouth, Hanover, NH, United States, ⁴Oregon Research Institute, Eugene, OR, United States

Introduction. Ecological momentary interventions (EMIs) are increasingly used to extend treatment for eating disorders (EDs) and obesity, yet their clinical value remains unclear. Methods. Eight databases were searched from inception to January 2026. Randomized and non-randomized studies evaluating EMI-based treatments for diagnosed EDs and/or obesity were included. Interventions were required to deliver real-time, context-sensitive support beyond passive self-monitoring. Data on intervention characteristics, outcomes, feasibility, and adherence were extracted. Risk of bias was assessed using RoB 2 and ROBINS-I. Results. Fourteen studies (nine RCTs; eight obesity, six ED) were included. In EDs, EMI-augmented interventions showed within-group reductions in binge eating and psychopathology, but superiority over CBT-based controls was inconsistent and mainly observed during maintenance. In obesity, interventions produced small to moderate improvements, with limited sustained effects over time. Feasibility and acceptability were high, though retention and engagement varied. Risk of bias was low in most RCTs but higher in non-randomized studies. Conclusions. EMIs appear to be feasible adjuncts for extending treatment into daily life, improving engagement and short-term outcomes. However, effects on long-term outcomes remain limited, highlighting the need for rigorously designed trials with extended follow-up and clearer operational definitions of EMI components.

1:45

Pilot Results Demonstrating Promise For A New, Co-Designed Program For People With Inflammatory Bowel Disease To Reduce Eating Disorder Psychopathology And Improve Body Image And Wellbeing
Mia L. Pellizzer¹, Maya Jabs¹, Réme Mountifield², Ruth Prosser², Ivanka Prichard³
¹Flinders University Institute for Mental Health and Wellbeing, Blackbird Initiative, Adelaide, Australia, ²Department of Gastroenterology, Flinders Medical Centre, Adelaide, Australia, ³Caring Futures Institute, Embrace Impact Lab, Flinders University, Adelaide, Australia

1. Introduction: Inflammatory Bowel Disease (IBD), including Crohn’s Disease and ulcerative colitis, are chronic conditions that cause inflammation in the bowel. IBD symptoms and treatments impact weight and appearance and increase risk for eating disorders. The aim of this study was to pilot our new co-designed body image and wellbeing intervention to reduce eating disorder psychopathology for people with IBD. 2. Methods: Participants with IBD were randomised to either the intervention (n=139) or wait-list control (n=149) condition. The intervention comprised 10 online, self-directed modules. Participants completed measures at pre-intervention, post-intervention, and after a one-month follow-up. 3. Results: At post-intervention, as compared to the wait-list control group, the intervention group reported significantly lower eating disorder psychopathology (d = -0.52), body image dissatisfaction (d = -0.44) and depressive symptoms (d = -0.25) and significantly higher body appreciation (d = 0.30) and health-related quality of life (d = 0.55). These differences (except depressive symptoms) were maintained at follow-up with small to moderate effect sizes. No benefit was observed for anxiety symptoms. Attrition was high (> 40%). 4. Conclusions: Results demonstrate benefits for most body image, eating disorder, and mental health outcomes. Further work is needed to understand and reduce attrition and compare the intervention to active control groups and interventions.

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Gut Microbiome Alterations In Adolescents With Anorexia Nervosa Are Linked To Weight Loss Severity And Influenced By Geographic Origin
Nadia Andrea Andreani¹, Lara Keller², Michael Zeiler³, Karlijn Kooij⁴, Benny van der Vijgh⁵, Andreas Karwautz³, Roger Adan⁴, Beate Herpertz-Dahlmann⁶, Astrid Dempfle⁷, Jochen Seitz², John Baines⁸
¹Department of Biology and Biotechnology , Rome, Italy, ²Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, LVR University Hospital Essen, Essen, Germany, Essen, Germany, ³Eating Disorders Care & Research Unit at the Department of Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria, Vienna, Austria, ⁴UMC Utrecht, Utrecht, Netherlands, ⁵Altrecht Eating Disorders Rintveld, Wenshoek, Netherlands, ⁶Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, RWTH Aachen University, Aachen, Germany, Aachen, Germany, ⁷Institute of Medical Informatics and Statistics, Christian Albrecht‐University Kiel, Kiel, Germany, Kiel, Germany, ⁸Institute for Experimental Medicine, Max Planck Institute for Evolutionary Biology, Kiel University, Kiel, Germany, Kiel, Germany

The gut microbiome has been implicated in the pathophysiology of anorexia nervosa (AN), but its relationship with clinical features remains underexplored. We analyzed 262 fecal samples from adolescent females (131 AN, 54 healthy controls [HC]) across three European sites using shotgun metagenomics, enabling the characterization of both bacterial and non-bacterial communities as well as functional profiles. Bacterial alpha diversity was reduced in AN, mainly driven by one site, and beta diversity was influenced by both site and disease status. Among clinical variables, BMI loss was significantly associated with microbiome composition, consistently across taxonomic levels. Differential abundance analysis identified enrichment of genera such as Akkermansia and depletion of commensals including Faecalibacterium. Viral community analysis revealed significant effects of both site and disease status, with a limited number of differentially abundant viral taxa associated with AN. Functional pathway analysis revealed a significant association with disease status, with AN characterized by increased abundance of pathways related to central metabolism and fermentation (e.g., TCA cycle, mannitol cycle), and reduced abundance of amino acid biosynthesis pathways. Microbiome alterations in AN are reproducible and biologically informative, show consistent associations with weight loss severity, and reveal meaningful functional shifts above and beyond site-related effects.

2:00

Testing A Biobehavioral Model For Predicting Illness Outcomes In Bulimic Syndromes
Pamela Keel¹, Lindsay Bodell², Jonathan Appelbaum¹, Diana Williams³
¹Florida State University, Tallahassee, FL, United States, ²University of Western Ontario, London, ON, Canada, ³Claremont McKenna College, Claremont, CA, United States

Introduction: After supporting the impact of weight suppression (WS) on severity of bulimia nervosa (BN) and related syndromes (BN-S) via biobehavioral alterations in reward satiation, we sought to test prospective associations with illness outcomes. Methods: Women with BN-S (n=321) and controls (n=78) completed structured clinical interviews, and 290 (73%) completed fixed and ad lib meal assessments of reward satiation and progressive ratio tasks of food and nonfood reward valuation at baseline, 6- and 12-month follow-up, with high retention (78%). Time-lagged models tested prospective associations between WS and fasting leptin, postprandial glucagon-like peptide 1 (GLP-1) response, reward satiation and valuation and between these variables and BN-S outcomes. Results: Greater WS prospectively predicted larger eating episode (binge) size, higher loss of control (LOC) frequency, and higher Eating Disorder Examination (EDE) scores at follow-up. Greater WS prospectively predicted reduced leptin and blunted GLP-1 response and greater ad lib intake at follow-up, and greater ad lib intake prospectively predicted larger episode size at follow-up. Although greater food reward valuation predicted greater LOC frequency at follow-up, other model predictions for reward valuation were not supported. Conclusions: Given that WS predicts poor response to cognitive behavioral therapy in BN, GLP-1 receptor agonists may be a promising adjunctive treatment to reduce binge eating by enhancing satiation.

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Blood Dna Methylation Patterns In Anorexia Nervosa: A Longitudinal Study On The Role Of Illness Duration And Symptom Remission
Linda Booij^1,2, Zsofia Nemoda ¹, Kevin Casey¹, Edith Breton³, Howard Steiger ^1,2
¹Eating Disorders Continuum, Douglas Mental Health University Institute, Montreal, QC, Canada, ²Department of Psychiatry, McGill University, Montreal , QC, Canada, ³4. Department of Fundamental Sciences, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada

Introduction: Previous studies have shown DNA methylation alterations in Anorexia Nervosa (AN). The present study investigated the extent to which illness duration in AN impacts DNA methylation and the effects of illness duration on methylation changes after symptom remission. Methods: We assessed leukocyte genome-wide DNA methylation in 198 women with active AN, 62 showing stable one-year remission of AN and 93 with no eating disorder. Follow-up data (mean 15.3 weeks) were available for 108 AN-active participants. Results: Compared to the no ED and AN-remitted groups, women with active AN had altered methylation in genes related to mental status, metabolism and immune function (Q<.01). In AN-active participants, longer illness duration was associated with lower methylation in the promoter region of the serotonin receptor 2A gene (HTR2A) (7 CpGs, Q<.05). HTR2A has been linked previously to risk of AN, obsessionality and compulsivity. Regardless of illness duration, BMI increases were linked to methylation changes in genes linked to lipid and glucose metabolism, cellular functions, and immune processes (Q<.05). Conclusions: Results suggest chronicity-linked, but reversible alterations of methylation patterns in AN, and support a pathophysiological model of AN with psychiatric, metabolic, and immune components. Our results suggest an epigenetically-regulated effect by which long-standing AN may adversely affect the serotonin system--which is thought to mediate various features of AN.

2:15

Identifying Candidate Biomarkers Of Physiological Recovery In Anorexia Nervosa And Atypical Anorexia Nervosa
Blair Uniacke^1,2, Joanna Steinglass^1,2, Pablo Del Sol Calderon^1,3, Alexandra Allam¹, Veronica Lee¹, Janet Schebendach¹, Evelyn Attia^1,4, B. Timothy Walsh¹
¹Columbia University, New York, NY, United States, ²New York State Psychiatric Institute, New York, NY, United States, ³Complutense University, Madrid, Spain, ⁴Weill Cornell Medicine, New York, NY, United States

Introduction: Reliance on body mass index (BMI) to define acute treatment goals for patients with anorexia nervosa (AN) has led to gaps in understanding the physiology of renourishment. For individuals with atypical AN (AAN), who are malnourished but not underweight, BMI has limited utility as a measure of health. Biological markers which reflect restoration of physical health with acute nutritional rehabilitation are needed to move beyond weight-based metrics. Methods: Participants were females with AN (n=29) or AAN (n=4) ages 14-50 years who completed a comprehensive battery of biological measures before and after inpatient nutritional rehabilitation on a specialized eating disorders unit. Results: BMI and percent body fat (%BF) increased with nutritional rehabilitation in AN (Time 1: M=15.6 kg/m², %BF=13; Time 2: M=19.4 kg/m², %BF=20.9) and AAN (Time 1: M=19.3 kg/m², %BF=22.8; Time 2: 22 kg/m², %BF=27.4). Across both groups, leptin levels increased from 9.3 ng/ml to 27 ng/ml. The frequency of abnormal levels of triiodothyronine (T3) fell from 32% to 10.5%, cortisol from 31% to 10.5%, and IGF-1 from 34.5% to 26.5% following nutritional rehabilitation. Conclusions: These preliminary findings document improvement across a range of biological indicators with refeeding. Additional study is required to determine which biological measures reflect physiological recovery in AN and AAN. Data collection is ongoing; additional data on these and other biomarkers will be presented.

1:00

Investigating Food Insecurity And Eating Disorder Pathology In Adolescents, Young Adults, And Older Adults: Evidence From Uk Cohort Studies
Akansha Naraindas¹, Vivienne Hazzard², Francesca Solmi³, Fidan Turk¹
¹Department of Psychology, University of Exeter, Exeter, United Kingdom, ²Charles Stewart Mott Department of Public Health, College of Human Medicine, Michigan State University, Flint, MI, United States, ³Division of Psychiatry, University College London, London, United Kingdom

Food insecurity (FI) is an increasingly prevalent social determinant of health, affecting an estimated 7.2 million people in the UK. Evidence (primarily from the USA) shows that food insecurity is associated with eating disorder (ED) pathology. At the same time, there is growing recognition that EDs occur across the lifespan. In the UK, FI disproportionately affects families with children (17%) and older adults (1.3 million aged 65+). These vulnerable groups have higher nutritional needs and may face increased ED risk and related health complications. Therefore, this study investigates cross-sectional and longitudinal associations between FI and ED pathology across multiple age groups using two UK cohort datasets: adolescents from UKHLS, and young and older adults from ALSPAC. Associations between food insecurity and multiple features of ED pathology (e.g., binge eating, restriction, avoidant/restrictive and compensatory behaviours, and negative body image) will be analysed using univariable and multivariable regression models. Analyses of adult data are ongoing; however, results among adolescents (N = 1,140) indicate that FI predicted an increase in later dieting behaviour (PR = 1.06, 95% CI: 1.00–1.12) but was not associated with appearance concerns. These findings will provide novel lifespan insight into the relationship between FI and ED pathology and have the potential to improve early identification of ED risk in food-insecure populations in the UK

1:15

Anticipatory And Consummatory Responses To Touch And Food Rewards In Anorexia Nervosa
Fiona Eslami Tehrani^1,2, Yanick Lahaye^1,2, Emilio Chiappini³, Philipp Lazen², Ema Lazić², Bianca Miculescu², Sarah Pernegger², Annika Teppert², Gudrun Wagner², Konstantin Kopp², Wolfgang Bogner², Michael Zeiler², Andreas Karwautz², Giorgia Silani¹
¹University of Vienna, Vienna, Austria, ²Medical University of Vienna, Vienna, Austria, ³Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany

Introduction – Several studies have demonstrated altered reward processing in anorexia nervosa (AN). However, inconsistencies regarding the direction and extent remain. While previous research has predominantly focused on disorder-specific rewards, such as food, comparing to non-disorder-specific rewards is key. Methods – We tested AN patients in different stages of the illness (N=89), and matched controls (N=50) using a newly developed reward paradigm which included trial-by-trial anticipation (wanting) and consumption (liking) of matched primary social (affiliative touch) and non-social (real food) stimuli, in combination with fMRI. Concurrently, their neural and facial muscular (i.e. corrugator supercilii muscle) activity was acquired by simultaneous fMRI and electromyography (EMG). Results – Behavioral data shows a significant increase of wanting of food in AN participants with a decrease of symptom severity compared to controls (p<0.0001) and significantly less liking of social rewards, independent from symptom severity (control vs. acute: p=0.0027, control vs. partial remission: p=0.0360, control vs. full remission: p=0.0013). Additionally, AN patients show overactivation during food consumption in Insula, STG and MFG, modulated by the level of reward, and decreased activation during the delivery of touch in SFG. Conclusion – The dissection of reward processing is an important step towards a better understanding of the complex mechanisms underlying AN.

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Trends In Disordered Eating And Weight Reducing Behaviours From 1995 To 2019 In A Norwegian Adolescent Cohort &Ndash; The Young-Hunt Study
Kirsti Kvaløy^1,2,3, Nadia Micali^4,5,6, Trine Tetlie Eik-Nes⁷
¹ HUNT Research Centre, Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, NTNU, Trondheim, Norway, ²Centre for Sami Health Research, Department of Community Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway, ³Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway, ⁴Institute of Biological Psychiatry, Mental Health Center Sct. Hans, Copenhagen University Hospital, Mental Health Services Copenhagen, Roskilde, Denmark, ⁵Center for Eating and feeding Disorders Research, Mental Health Center Ballerup, Copenhagen University Hospital, Mental Health Services Copenhagen, Copenhagen, Denmark, ⁶Great Ormond Street Institute of Child Health, University College London, London, United Kingdom, ⁷Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway

Introduction: In Norway, eating disorder diagnoses and disordered eating (DE) have increased markedly highlighting the need for trend analyses to guide prevention. Methods: The adolescent part (Young-HUNT) of the population‑based Trøndelag Health Study (HUNT) included 13–19-year-olds from three survey waves (1995–97, 2006–08, 2017–19), each with ~8,000 participants. Disordered eating (DE) was assessed using EAT‑7 with subscales oral control (EAT‑A) and bulimia/food preoccupation (EAT‑B). Weight‑reducing behaviors were measured using single‑item questions on perceived need and active attempts to lose weight. Linear trends were tested using Jonckheere–Terpstra and linear‑by‑linear tests stratified by age and sex. Results: Across waves, girls reported disordered eating (DE) and weight‑reducing behaviours more often than boys. Prevalence of DE was higher in 1995/97 and 2017/19 compared to 2006/08. Among girls, bulimia and food preoccupation increased significantly from 1995 to 2019, reaching 11.9% (13–15 years) and 18.1% (16–19 years) in 2017/19. No increase in DE trends were observed in boys. Parallel with an increase of BMI over time, active weight‑loss attempts increased in both sexes, whereas reporting a need to lose weight without active weight loss attempts declined. Conclusions: Parallel increases in weight‑reducing behaviors across both sexes and bulimic and food preoccupation symptoms in girls along with rising BMI trends represent a public health concern.

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Efficacy Of Mantra Compared To Treatment As Usual In Adolescents And Young Adults With Anorexia Nervosa In Austria
Gudrun Wagner
Medical University of Vienna

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3:37

Family Therapy For An Across The Age Span
Julian Baudinet
King's College London

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4:00

A Randomised Sham-Controlled Feasibility Trial Of Intermittent Theta Burst Stimulation For Young People With Persistent Anorexia Nervosa: The Raise Trial
Amelia Hemmings
King's College London

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Home Treatment (Hot) Is More Effective Than Weight-Restoring Inpatient Treatment (Ip) In Adolescent Anorexia Nervosa (An) � Results Of A Large Multicenter Rct At One Year Follow-Up
Beate Herpertz-Dahlmann
Aachen University

P200

Long‑Standing Eating Disorders: Clinical Characteristics And Short‑Term Responses To Outpatient Treatment
Linda Booij^1,2, Léa Larochelle¹, Samantha Ginsberg¹, Howard Steiger ^1,2
¹Eating Disorders Continuum, Douglas Mental Health University Institute, Montreal , QC, Canada, ²Department of Psychiatry, McGill University, Montreal , QC, Canada

Introduction: Long illness duration has been thought to be characteristic of a unique subgroup of people with eating disorders (EDs). However, studies often use small samples or do not comprehensively assess the range of common ED variants or illness durations. Methods: We measured the impact of illness duration, treated as continuous and categorical (<7, 7–14 or > 14 years), on ED-symptom severity, concurrent symptoms, personality, motivation and functional impairment in 1,000 individuals with AN, BN or OSFED starting a new episode of specialized outpatient treatment. Treatment response over the first 4 months was assessed in 338 patients. K‑means cluster analyses tested whether illness duration was associated with a distinct clinical profile. Results: Findings in individuals with long-standing EDs were comparable to those with shorter illness durations on measures of ED-symptom severity, psychiatric symptoms, personality, and emotion regulation. However, those with prolonged illness were more likely to have bulimic symptoms and reported higher functional impairment and autonomous motivation (p <.005). K‑means cluster analysis suggested that long‑standing illness was not associated with a distinct clinical profile (p=.39). Illness duration did not moderate treatment response (p>.15). Conclusions: Our results suggest that long‑standing EDs are not a unique, less-treatment responsive subtype. Illness duration alone does not seem to be an important parameter for treatment planning.

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Transforming Percentage Of Median Body Mass Index (%Mbmi) Scores Into Corresponding Bmi Z-Scores Yields Discrepancies For Age And Sex: Implications For Pediatric Eating Disorder Researchers And Clinicians
Linus Imken¹, Abigail Matthews², Johannes Hebebrand³
¹Department of Child and Adolescent Psychiatry, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt Universität zu Berlin, Berlin, Germany, ²Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States, ³Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany

Anorexia nervosa (AN) and atypical AN are distinguished by the presence or absence of a significantly low body weight. In children and adolescents, the population-based age- and sex-adjusted weight characteristics, BMI centile, BMI z-score (BMIz), and percentage of median BMI (%mBMI) are used to diagnose underweight. Whereas BMI centile and BMIz are interconvertible, %mBMI is not. We extend previous analyses to illustrate a) age- and sex-dependent discrepancies between %mBMI and BMIz and b) the non-linear relationship between BMIz and absolute body weight. Based on Centers for Disease Control growth charts, BMIz corresponding to the 65, 75, and 85%mBMI were determined for males and females aged 10 to 18 years. Body weights (in kg) corresponding to BMIz ranging from 0 to -7 (based on average heights) were also calculated and compared. Throughout the age span, BMIz corresponding to 65%mBMI ranged from -5.0 to -6.9 in males and -4.5 to -5.2 in females; at 75%mBMI, from -2.9 to -3.6 in males and -2.6 to -2.9 in females; and at 85%mBMI, from -1.4 to -1.7 in males and -1.3 to -1.4 in females. Body weight increments (in kg) per 1 BMIz were non-linear and dependent on reference BMIz. Transformations between %mBMI and BMIz are not linear, and these characteristics cannot be used interchangeably. Use of both BMIz and %mBMI in eating disorder research limits meta-analyses. Field consensus for universal weight-related assessment in adolescents is necessary.

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Trending Down, Complexity Up: %Tgw Trajectories As A Red Flag For An-Plus
Debra K. Katzman^{1, 2,3}, Anne Hughes^1,3,4, Lucie Turner^1.2.5, Marian Coret^1,2,, Tania Turrini^1,6, Tim Guimond^2,7, Melissa McCradden⁸
¹Hospital for Sick Children , Toronto, ON, Canada, ²University of Toronto, Toronto, ON, Canada, ³Research Institute, Hospital for Sick Children, Toronto, ON, Canada, ⁴Department of Social Work, Toronto, ON, Canada, ⁵Department of Bioethics, Toronto, ON, Canada, ⁶Department of Clinical Dietetics, Toronto, ON, Canada, ⁷HQ Health Hub Addictions Division, Centre for Addictions and Mental Health, Toronto, ON, Canada, ⁸Women’s and Children’s Health Network and Australian Institute for Machine Learning, Adelaide, Australia

Introduction: A subset of adolescents with anorexia nervosa (AN) have severe, treatment‑nonresponsive illness with repeated/prolonged hospitalizations. Our group developed the AN‑PLUS construct (Poor quality of life, Lack of response to first‑line treatment, medically severe and Unstable, Severe symptomatology) to support early identification and tailored care. Methods: We conducted a retrospective chart review at SickKids (Toronto) of youth 10–18 years with DSM‑5 AN between 2018–2023. Severe AN was defined as nonresponse to FBT and ≥2 admissions within 6 months or ≥1 admission >4 months. Groups were defined by longitudinal admission percent treatment goal weight (%TGW) trajectories. Results: Of 491 adolescents with AN, 67 (13.6%) met inclusion criteria. Two trajectory groups emerged overall: declining admission %TGW (DAT; n=14) vs stable/increasing admission %TGW (SIAT; n=53). DAT showed greater complexity (constant observation(p<0.011), restraints(p<0.002), code white events(p<0.042), involuntary admissions(p<0.029), family history of ED(p<0.02)) and younger symptom onset 11.9 (1.59) vs 13.1 (1.7) years (p<0.017). Exploratory analysis using lower %TGW at second admission plus chemical restraint at index admission identified DAT with 92.9% sensitivity and 84.9% specificity. Conclusions:13.6% of hospitalized adolescents with AN met AN‑PLUS criteria. Declining admission %TGW marked a high‑complexity subgroup whose earlier identification could enable individualized care pathways.

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The Accuracy And Suitability Of Eating Disorder Screening Tools For Binge Eating Disorder And Bulimia Nervosa In A Primary Care Setting: A Systematic Review And Narrative Summary
Stella Kozmér^1,2, Ruichen Yin⁴, Joseph Evans³, Alex Burns^1,5, Jane R. Smith¹
¹University of Exeter Medical School, University of Exeter, Exeter, UK, Exeter, United Kingdom, ²Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom, ³The Medical School, University of Sheffield, Sheffield, United Kingdom, Sheffiel, United Kingdom, ⁴Department of Psychology, University of Exeter, Exeter, UK, Oxford, United Kingdom, ⁵Three Spires Medical Practice, Truro, Cornwall, United Kingdom, Truro, United Kingdom

Background: Despite available screening tools for eating disorders (EDs), the accuracy and suitability of these in identifying Binge eating disorder (BED) and Bulimia nervosa (BN) in a primary care setting are undetermined, despite BED/BN being the most common EDs. Aim: To evaluate the accuracy and suitability of ED screening tools for BED/BN in a primary care setting. Method: A systematic review searching six databases. Two independent reviewers screened studies for inclusion. Studies were included that assessed the accuracy and/or suitability of screening tools for BED/BN in primary care. Quality was assessed using the Mixed Methods Appraisal Tool. A narrative summary was created after integrating the data using a convergent segregated approach. Results: Four studies met inclusion criteria. These reported on BEDS-7, EDE-Q and SCOFF screening tools. No studies reported on the accuracy of screening tools for BED and suitability for BN. BEDS-7 and EDE-Q screening tools reported variations in their suitability in primary care. The main barrier to implementation in primary care was time constraints and a lack of trust in screening. SCOFF showed high sensitivity (97.88%–100%) for BN but had lower specificity (89.6%–94.4%), increasing false positives. Conclusion: ED screening tools face feasibility and accuracy concerns for BED/BN in a primary care setting. Further research is needed to validate screening tools’ accuracy and suitability in a primary care setting for BED/BN in the general population.

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Validation Of The Eating Disorder Assessment For Dsm-5 (Eda-5) In A Unified Portuguese Version From Brazil And Portugal
Cassia Molin¹, Rita Ramos², Carlos E. F. Moraes¹, José C. Appolinário¹, Paulo PP Machado²
¹Federal University of Rio de Janeiro, Psychiatry Institute , Rio de janeiro, Brazil, ²University of Minho, School of Psychology, Braga, Portugal

Introduction: The Eating Disorder Assessment for DSM-5 (EDA-5) is an online diagnostic instrument developed to identify all feeding and eating disorders (ED) included in DSM-5. This study aims to evaluate the validity of the unified Portuguese version of the EDA-5 in clinical samples from Brazil and Portugal. Methods: Participants (≥16 years) currently in treatment for an ED are being recruited from hospital units in both countries (planned n = 120). Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were calculated by comparing diagnoses obtained from the EDA-5 with those from the SCID-P (Brazil) and the EDE interview (Portugal). Results: We present data from Brazil (n=60; 93% females), as data collection in Portugal is ongoing (n=10; 100% females). In Brazil, considering the accuracy to identify any diagnosis, the EDA-5 exhibited sensitivity of 94%, specificity of 44%, PPV of 91%, and NPV of 57%. Specifically, to identify Anorexia Nervosa (AN), the EDA-5 had a sensitivity of 86%, specificity of 100%, PPV of 100%, and NPV of 98%. For Bulimia Nervosa, the instrument had a sensitivity of 52%, specificity of 95%, PPV of 86%, and NPV of 76%. For Binge Eating Disorder (BED), EDA-5 had sensitivity of 67%, specificity of 87%, PPV of 74% and NPV of 83%. Conclusion: Overall, the results suggest that EDA-5 had a good performance in identifying ED in a Brazilian clinical sample, particularly in AN and BED.

P205

Factor Structure Of The Parent-Completed Child Inflexibility Index To Assess Eating-Related Inflexibility Throughout Childhood
Brianne N. Richson¹, Hana F. Zickgraf², Courtney E. Breiner³
¹Sanford Center for Biobehavioral Research, Fargo, ND, United States, ²Rogers Behavioral Health Research Center, Oconomowoc, WI, United States, ³Children's Healthcare of Atlanta, Atlanta, GA, United States

Introduction: Eating-related inflexibility (e.g., insistence on certain foods, strong preparation/presentation preferences) characterizes children who are ‘picky’ eaters and whose selective eating constitutes an avoidant/restrictive food intake disorder (ARFID) diagnosis. The Inflexibility Index (IFI) is a measure of such inflexible eating. The child version of this measure for parents has not been validated. Methods: We tested the factor structure of the Child IFI (CIFI), completed by parents (N=505) with a child aged 5-17. Results: Confirmatory factor analysis supported that the one-factor CIFI model (factor estimates .59-.83) had overall good fit to the data with scaled test/fit statistics as follows: χ²(65)=567.09, p<.001, CFI=.96, TLI=.95, SRMR=.05. As RMSEA was poor (.12), modification indices were reviewed for item redundancy and theory-driven modifications. Items 3 (prefers not to eat with people outside family) and 10 (only comfortable eating in a certain place[s]) substantially covaried. Items 1 (letting foods touch) and 12 (prefer to not eat a food that touched a disliked food) notably covaried. Items 5 (does not like mixed foods) and 6 (does not like food with “things” in them) also notably covaried. When these pairs were each parceled in a modified model, RMSEA improved slightly. Conclusions: The CIFI is a brief parent-report measure of eating-related inflexibility in children with promise for measuring eating-related flexibility in childhood and ARFID treatment.

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No Difference In Weighing Tendencies In Restrictive- And Binge-Type Eating Disorders; Lower Approach Motivation In Arfid
Stefania L. Yee¹, Jennifer J. Thomas¹, Kamryn T. Eddy¹, Kyle P. De Young², Paraskevi. E Kambanis¹
¹Massachusetts General Hospital, Boston, MA, United States, ²University of Wyoming, Laramie, WY, United States

INTRODUCTION: Frequent self-weighing to evaluate weight (approach) is common in eating disorders (EDs), as is deliberately attempting to avoid knowledge of weight (avoidance). We examined weighing tendencies across EDs, hypothesizing that those with restrictive-type EDs (ED-R) would score higher on approach, individuals with binge-type EDs (ED-B) would score higher on avoidance, and those with ARFID would score lower on both subscales, reflecting neither approach nor avoidance motivation. METHOD: Patients with ED-R (n = 47), ED-B (n = 35), and ARFID (n = 27) ages 10+ years completed the Approach/Avoidance of Weighing Questionnaire (AAWQ). One-way ANOVAs examined diagnostic group differences in approach and avoidance. RESULTS: Groups differed significantly on approach (F[2,106]=3.88, p=.024, 2=.07), but not avoidance (F[2,106]=.58, p=.576, 2=.56). Specifically, ARFID scored significantly lower on approach than ED-R (p=.007) but did not differ significantly from ED-B (p=.128). ED-R and ED-B did not significantly differ on approach (p=.620). CONCLUSIONS: ED-R and ED-B demonstrated no differences in approach weighing tendencies, consistent with their shared overvaluation of shape/weight. ARFID was distinct, showing significantly lower approach than ED-R, consistent with its non-weight/shape-driven etiology. Notably, no group was distinguished by elevated avoidance, suggesting avoidance of weighing may not be a diagnostically specific feature across ED presentations.

P207

Fear Of Negative Evaluation Predicts Eating Disorder Psychopathology In A Mixed-Sex Community Sample Of Adolescents
Victoria Burmester, Alexandra Musat, Dasha Nicholls
Imperial College London, London, United Kingdom

Introduction: Adolescence is a critical period of vulnerability for eating disorders (ED), characterised by heightened sensitivity to social evaluation. Socio-cognitive processes such as the fear of negative evaluation and cognitive empathy may contribute to ED psychopathology, yet evidence in mixed‑sex community samples remains limited. Methods: A community sample of 191 adolescents aged 16–19 completed the Eating Disorder Diagnostic Scale, Brief Fear of Negative Evaluation and Cognitive Empathy Scale. Sex differences were examined using Mann–Whitney U tests. Mediation and regression analyses were conducted using PROCESS with bootstrapped confidence intervals. Results: Higher fear of negative evaluation was a strong predictor of ED symptoms (β = .46, 95% CI [0.30, 0.62]). ED symptoms were reported more in females than in males (r^rb = −.36, 95% CI [−.50, −.20]); however, the association with negative fear of evaluation was not moderated by sex (β=-.21, 95% CI [-.47, .51]). Cognitive empathy partially mediated the association between sex and ED symptoms (indirect = 0.17, 95% CI [0.04, 0.33]). Conclusions: Fear of negative evaluation emerged as a robust predictor of eating disorder psychopathology across sexes, reinforcing the central role of socio‑evaluative threat in adolescent ED risk. Fear‑based social appraisal processes may be critical for early identification and prevention.

P208

Problematic Eating Behavior And Gut Dysbiosis In Binge Eating Disorder And Obesity
Eva Conceição¹, Catarina Gomes^{1, 2}, Abigail González², Clara Guimarães¹, Adriana Sampaio³, Clarisse Nobre^2,4
¹University of Porto, Faculty of Psychology and Education Sciences, Porto, Portugal, ²CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal, ³CIPsi – Psychology Research Centre, University of Minho, Braga, Portugal, ⁴LABBELS - Associate Laboratory, Braga, Portugal

INTRODUCTION: Individuals with binge eating disorder (BED) often experience under-treated psychopathology and problematic eating behaviors, contributing to high comorbidity with obesity. A deeper understanding of the psychological and biological mechanisms of both conditions may lead to more effective treatment approaches for BED. This study characterizes gut microbiota and eating behavior in normal-weight individuals, obesity with BED, and obesity without BED. METHODS: Participants were assessed using the Eating Disorder Examination. Fecal samples and self-report measures, such Loss of Control Eating Scale (LOCES) and the Repetitive Eating Questionnaire (Rep(eat)-Q) were obtained. RESULTS: The obesity with BED group showed the lowest Blautia and Bifidobacterium abundance and the highest Faecalibacterium abundance compared to the other groups. Obesity and BED also presented higher Ruminococcus and lower Subdoligranulum abundance compared to groups without BED. Regarding self-report measures, the obesity with BED group showed significantly higher compulsive grazing behavior (Rep(eat)-Q subscale - M_OB+BED=3.24,SD=1.74; H(2) = 6.198, pairwise p=.045, M_OB=0.86,SD=1.00,p=.015), and a tendency toward higher loss of control (M_OB+BED=2.62,SD=0.89; M_OB=1.66, SD=0.57; M_NW=1.76, SD=0.55; H(2)=4.876, p=.087). DISCUSSION: Preliminary findings suggest more gut dysbiosis markers and higher eating-related psychopathology in individuals with obesity and BED.

P209

Gut Microbiome Profiles In Avoidant/Restrictive Food Intake Disorder
Stefana Darvariu¹, Elisa Asanza², Brittani Martino², Jonathan Xiang², Stefania Yee², Lauren Breithaupt², Kendra R. Becker², Helen Burton-Murray², Stephanie Harshman², Madhusmita Misra², Laura M. Holsen², Kamryn T. Eddy², Jennifer J. Thomas², Elizabeth Lawson², Kenneth Klingenberg Barfod ³, Nadia Micali¹
¹Center for Eating and feeding Disorders Research (CEDaR), Mental Health Center Ballerup, Copenhagen University Hospital – Herlev and Gentofte , Copenhagen, Denmark, ²Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, ³University of Copenhagen, Department of Food Science, Section for Food Microbiology, Gut Health, and Fermentation, Copenhagen, Denmark

Introduction: Avoidant/restrictive food intake disorder (ARFID) is characterized by persistent disturbances in eating leading to inadequate energy or nutrient intake. Behaviors are independent of body image concerns and may stem from low interest in food, sensory-based avoidance, or fear of adverse consequences. Although the gut microbiome (GM) has been implicated in eating disorders, evidence in ARFID remains limited. Methods: This study aimed to determine GM differences between individuals with ARFID (n = 35) and healthy controls (HC) (n = 13) in a US cohort. Fecal samples were sequenced using Oxford Nanopore sequencing technology. Results: GM composition differed between individuals with ARFID and HC at the presence–absence level, as indicated by significantly altered Jaccard beta diversity, whereas abundance‑based beta diversity and alpha diversity did not differ significantly between groups. Additionally, differential abundance analysis identified several genera enriched in ARFID, including Eggerthella, Lachnoclostridium, Thomasclavelia, and Eubacterium, alongside reduced abundance of Holdemanella compared with HC. Conclusions: Together, presence-absence-based differences in the GM composition and the taxon‑level abundance changes suggest that ARFID presents selective GM alterations and metabolic potential, rather than global restructuring, warranting future taxon‑focused functional studies.

P210

Structural Sexism And Eating Disorder Symptom Severity: Testing Relationships In A Multi-Diagnostic, Treatment-Enrolled Sample
Haley A. Henriksen¹, Alan Duffy², Sophie Abber^3,4, Renee D. Rienecke², Thomas Joiner³, Lauren N. Forrest¹
¹Department of Psychology, University of Oregon, Eugene, OR, United States, ²Eating Recovery Center and Pathlight Mood & Anxiety Centers, Denver, CO, United States, ³Department of Psychology, Florida State University, Tallahassee, FL, United States, ⁴University of California, San Diego Eating Disorders Center, San Diego, CA, United States

Introduction: Stigma influences psychopathology. One form of stigma—sexism—may be especially relevant for eating disorders (EDs) given gender differences in ED prevalence and relevance of sexist principles to ED risk (e.g., objectification). We assessed the relationship between structural sexism and ED symptoms at treatment intake and discharge, expecting positive associations. Method: The sample was N=6,588 people age 8–70 (M=22.5) in ED treatment reporting female sex or girl/woman gender. ED symptoms were measured with the Eating Disorder Examination Questionnaire Global score. State-level sexism was measured via two composites created from publicly available data: material sexism (material inequities between genders) and cultural sexism (sexist attitudes). Individual-level data were mapped to structural data with zip codes. Results: Material sexism (p=.85) and cultural sexism (p=.05) were not associated with ED symptoms at intake. Material sexism was also not associated with ED symptoms at discharge (p=.06). However, cultural sexism was negatively related to ED symptoms at discharge (p=.009), though effect sizes were negligible (semi-partial r²=.002). Conclusions: Contrary to theoretical rationale, most models were nonsignificant; the only significant model opposed hypotheses. Questions are raised as to whether sexism may impact ED development but not maintenance, the level(s) at which sexism influences ED symptoms, and ability to adequately measure structural stigma.

P211

Unravelling The Complex Relationship Between Loneliness And Eating Disorders In Young People: An Ecological Momentary Assessment Study
Basak Ince¹, Carina Kuehne¹, Rosie Tatham¹, Mariana Lopes¹, Callum Bryson¹, Caroline Le Luel¹, Matthew D Phillips², Lucy Gallagher¹, Sarah Moody³, Delia Fuhrmann⁴, Nicholas Cummins⁵, Helen Sharpe³, Ulrike Schmidt^1,6
¹Centre for Research in Eating and Weight Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom, ²Department of Psychology, School of Life Sciences and the Environment, Royal Holloway, University of London, London, United Kingdom, ³School of Health in Social Science, University of Edinburgh, Edinburgh, United Kingdom, ⁴Department of Psychology, King’s College London, London, United Kingdom, ⁵Department of Biostatistics & Health Informatics, King’s College London, London, United Kingdom, ⁶South London and Maudsley NHS Foundation Trust, London, United Kingdom

Introduction: Young people are the population most likely to struggle with loneliness. In eating disorders (EDs), loneliness may not only be a consequence, but also a precipitating and maintaining factor of the EDs. However, the moment-to-moment dynamics of this relationship in real-world settings remain underexplored. This study examines within- and between-person bidirectional relationships between loneliness and ED behaviours across illness stages. Methods: Participants from a large prospective cohort study, aged 16–25 with early-stage (n=173, illness duration <3 years) or later-stage ED (n=380, illness duration ≥3 years) completed brief in-the-moment assessments at six random times a day, over six consecutive days via a smartphone app. Assessments captured loneliness, ED behaviours (e.g., restriction, binging, purging, excessive exercise), and contextual factors including social setting and company. Lagged multilevel models will examine momentary within- and between-person bidirectional associations across illness stages. Results: Within- and between-person momentary temporal dynamics between loneliness and ED behaviours, the role of contextual factors, and whether patterns differ by illness stage will be presented. Conclusions: Findings will advance understanding of how loneliness and ED behaviours interact in young people’s lives, and how context shapes these dynamics, informing personalised just-in-time interventions targeting loneliness in young people with EDs.

P212

Endocannabinoid, Reward, And Neuroaxonal Pathways In Anorexia Nervosa And Avoidant/Restrictive Food Intake Disorder
Katarzyna Jowik-Krzeminska^1,2, Marta Tyszkiewicz-Nwafor^1,2
¹Department of Adult Psychiatry at Poznan University of Medical Sciences , Poznan, Poland, ²Department of Adult Psychiatry at Poznan University of Medical Sciences , Poznan, Poland

Objectives
To synthesize current human evidence on the endocannabinoid system (ECS), reward circuitry and neuronal injury markers in anorexia nervosa (AN) and avoidant/restrictive food intake disorder (ARFID).
Methods
We narratively reviewed studies on ECS genetics, receptor availability and circulating ligands, functional MRI/PET of food‑ and reward‑related processing, and serum/plasma neurofilament light chain (NfL), tau and glial fibrillary acidic protein (GFAP) in AN and ARFID.
Results
In AN, ECS alterations (CNR1/FAAH variation, increased CB1 availability, dysregulated endocannabinoids) are linked to eating‑disorder psychopathology and affective symptoms. Neuroimaging shows abnormal dopaminergic reward processing and fronto‑striatal hyperconnectivity between reward and cognitive‑control regions. Acute AN is additionally characterized by elevated NfL, tau and GFAP, partly normalizing with weight restoration but associated with cortical thinning and white‑matter alterations. ARFID instead shows hyperactivation of threat‑, sensory‑ and attention‑related networks during food‑cue processing, with phenotype‑specific patterns and no current data on ECS or neuronal‑injury markers.
Conclusions
Findings support partially divergent neurobiological pathways in AN and ARFID and highlight the need for longitudinal, multimodal studies—particularly in youth—to refine mechanism‑based interventions.

P213

Risk Factors And Prodromal Symptoms That Predict Future Onset And Persistence Of Atypical Anorexia Nervosa
Eric Stice¹, Felix Zhan¹, Sareena Shah¹, Yuko Yamamiya²
¹Stanford University, Stanford, CA, United States, ²Temple University, Japan Campus, Tokyo, Japan

Objective: Because little is known about atypical anorexia nervosa (AAN), the present report tested whether AAN is associated with similar levels of psychosocial impairment as other recognized eating disorders, tested whether established eating disorder risk factors and prodromal symptoms predict future onset of AAN and exploratory analyses tested whether these same variables predicted persistence of AAN. Method: Data from 4 prevention trials that targeted high-risk young women with body image concerns (N=1,952; M age 19.7, SD 5.7) and annual diagnostic interview data over 3-year follow-ups was collected. Results: Those with AAN showed similar levels of functional impairment as individuals with other types of eating disorders. Baseline thin-ideal internalization, body dissatisfaction, negative affect, dieting, high BMI, psychosocial impairment, feeling fat, fear of weight gain, weight/shape overvaluation and lower than expected BMI predicted future AAN over 3-year follow-up. Random assignment to the Body Project eating disorder prevention program significantly reduced future onset of AAN. Elevated fear of weight gain and weight/shape overvaluation predicted future persistence versus remission of AAN. Conclusions: Risk factors such as thin-ideal pursuit, body dissatisfaction, negative affect, and prodromal symptoms predicted AAN onset, and prodromal symptoms also predicted its maintenance, which are both novel contributions to the literature.

P214

Subjective Versus Objective Executive Function Measures In Patients With Eating Disorders
Siri Weider^{1, 2}, Tora Thorsrud^{1, 2}, Camilla L Dahlgren³, Odin Hjemdal¹, Linda Thorsen¹
¹Department of Psychology, Faculty of Social and Educational Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway, ²Eating Disorder Unit, Department of Psychiatry, Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway, ³Department of Psychology, Oslo New University College, Oslo, Norway

Introduction. Studies have found difficulties in executive functions (EF) in patients with eating disorders (ED), evidenced by both subjective (self-reported) and objective (neuropsychological) measures. However, as found in other patient groups, these measures show limited correspondence. The aim of this study was thus to investigate the association between subjective and objective measures in patients with ED, and to explore factors associated with this discrepancy. Methods. A total of 69 patients with ED completed the baseline assessment in a randomized controlled trial on the efficacy of transdiagnostic Cognitive Remediation Therapy. Included in this assessment were subjective and objective measures of EF. Results: Analyses showed no association between subjective and objective EF measures. While subjective EF difficulties were positively associated with psychological maladaptation, no such association was found for the objective measures. However, objective EF was positively associated with general cognitive ability. Also, the objective-subjective EF discrepancy was predicted by general cognitive ability and psychological maladaptation. Conclusions: Subjective and objective measures appear to assess distinct aspects of EFs. However, both general cognitive ability and psychological maladaptation were identified as key factors in explaining the discrepancy. This underlines the significance of assessing patients with both types of EF measures to capture their difficulties.

P215

The Triangulation Between Positive Body Image, Eating Disorder Symptoms, And Depressive Symptoms In Adolescence &Ndash; A Network Analysis
Laura M. Derks, Alicia S. Ridder, Martin Holtmann, Tanja Legenbauer
LWL University Hospital Hamm of the Ruhr-University Bochum, Hamm, Germany

Introduction: Body image (BI) is strongly linked to eating disorders and depression, yet research has largely emphasized its negative aspects. Positive BI, especially body appreciation, may act as a protective factor. This is especially relevant during adolescence, a developmental period characterized by increased BI concerns alongside a rise in depressive symptoms. Therefore, the current study examines the triangular associations between body appreciation, eating disorder symptoms, and depressive symptoms in a clinical adolescent sample. Methods: Data are drawn from routine diagnostic assessments of inpatients at a child and adolescent psychiatric hospital (N = 420). First, associations between body appreciation and psychopathology will be compared between adolescents with and without eating disorders. Second, a network analysis will be conducted, including body appreciation (BAS-2), eating disorder symptoms (ChEDE-8), and depressive symptoms (PHQ-9). Central and bridge symptoms linking body appreciation, eating disorders, and depression will be identified. Results: Data preparation and analysis are ongoing. Findings will be presented at the conference. Conclusions: This study contributes to a more balanced understanding of BI by focusing on its positive dimensions. It aims to clarify the potential protective role of body appreciation against depressive and eating disorder symptoms in clinically affected adolescents.

P216

A Network-Based Examination Of Shared And Distinct Psychological Features In Bulimic-Spectrum And Behavioral Addictive Disorders
Susana Jimenez-Murcia^1,2, Michael Zeiler³, Isabel Sanchez^1,2, Monica Gomez-Peña¹, Lucero Munguia¹, Isabel Baenas¹, Lorena de Blas-Soto¹, Anahi Gaspar-Perez¹, Fernando Fernandez-Aranda^1,2
¹Department of Clinical Psychology, University Hospital of Bellvitge-IDIBELL and CIBERobn, Hospitalet de Llobregat, Spain, ²Department of Clinical Sciences, School of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain, ³Medical University of Vienna, Department for Child and Adolescent Psychiatry, Eating Disorders Unit, Vienna, Austria

Bulimic-spectrum disorders (BSD) and behavioral addictions (BA) share clinical features and personality traits. This study applied psychological network analysis to compare symptom-trait interactions across individuals with BSD, BAS, and comorbid BSD+BA, and to explore their transdiagnostic characteristics. Methods: A sample of female patients with BSD (n=955), BA (n=411) and comorbid BSD+BA (n=267) provided data on general psychopathology (SCL-90-R) and personality traits (TCI-R). Regularized partial correlation networks using SCL-90-R and TCI-R subscales were calculated separately by group. Node centrality and bridge strength were calculated and compared between the groups. Results: Across all three groups, anxiety and harm avoidance showed the highest node strength. While self-directedness showed high centrality in BSD, depression was more central in the BSD+BA group. Harm avoidance (in BSD and BA) and depression (in BSD+BA) showed highest bridge centrality, indicating their role in linking psychopathology and personality. Discussion and Conclusion: The present findings support a transdiagnostic conceptualization of BSD and BA emphasizing shared affective and self-regulatory mechanisms rather than disorder-specific symptom patterns. Clinically, targeting anxiety-driven avoidance, emotion regulation deficits, and impaired self-regulatory capacities may yield broad therapeutic benefits across diagnostic boundaries.

P217

Clinician Perspectives On Barriers And Enablers To Autism-Affirming Eating Disorder Care.
Emy Nimbley^1,2, Amelia Austin¹, Kate Tchanturia^3,4, Kai Thomas⁵, Catherine R. G. Jones⁵, Karri Gillespie-Smith¹, Fiona Duffy^1,2
¹Department of Clinical Psychology, School of Health in Social Science, University of Edinburh, Edinburgh, United Kingdom, ²NHS Lothian Child and Adolescent Mental Health Services, Royal Edinburgh Hospital, Edinburgh, United Kingdom, ³Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom, ⁴ Department of Psychology, Illia State University, Tbilisi, Georgia, ⁵5. School of Psychology, Cardiff University, Cardiff, United Kingdom

Introduction: Autistic people report more negative experiences of eating disorder (ED) treatment and are at greater risk of requiring higher intensity ED services. In response, some ED clinicians are increasingly implementing autism-affirming adaptations to care. However, there remains little guidance or understanding on how autism-informed adaptations are implemented in practice. This study explored clinician-perceived barriers and enablers to implementing autism-affirming adaptations in UK ED services. Methods: Semi-structured interviews were conducted with 12 clinicians in multidisciplinary roles across UK ED services who were beginning to implement autism-affirming care. Data were analysed using critical realist thematic analysis. Results: Clinicians described many barriers associated with implementing autism-affirming care underpinned by longstanding beliefs about the risks of accommodating ED behaviours. This contributed to anxiety about making adaptations to care and the potential to over- or under-accommodate autistic needs. An underlying assumption that evidence-based practice solely equates to manualised treatment for EDs constrained adaptation. Enablers included a commitment to individualised formulation and care and valuing a diverse multidisciplinary team. System-level barriers included siloed autism and ED resources and training. Conclusion: Autism-affirming adaptations challenge some core underpinning messages historically embedded in siloed ED services.

P218

Understanding Arfid In Neurodiverse And Neurotypical Children: Clinical And Measurement Considerations
Natalie Saba^{1, 2}, James Lock², HaLi Boyce², Ainsley Cogburn², Brittany Matheson²
¹Palo Alto University, Palo Alto, CA, United States, ²Stanford University School of Medicine, Stanford, CA, United States

Introduction: Avoidant/Restrictive Food Intake Disorder (ARFID) frequently co-occurs with neurodevelopmental disorders (NDDs), though the impact of comorbidity on ARFID symptoms remains unclear. Methods: This study compared children with low-weight ARFID with and without comorbid NDDs (ASD and/or ADHD) across ARFID severity, symptom profiles, psychosocial functioning, and parental self-efficacy, and evaluated psychometric properties of the Pica, ARFID, and Rumination Disorder Interview (PARDI). Data was drawn from a randomized clinical trial (N=98; aged 6-12). ARFID severity and symptom profiles were assessed with the PARDI and %EBW, psychosocial functioning with the Social Difficulties Questionnaire (SDQ), and parental self-efficacy with the Parents vs. ARFID (PvARFID) Scale. Analyses included t-tests with effect sizes, nonparametric tests, internal consistency, and exploratory factor analysis. Results: Children with ARFID and NDDs (N=35) showed no differences in severity, sensory and interest profiles, or parental self-efficacy, but had significantly less fear of aversive consequences (p=.007) and lower psychosocial functioning (p<.001) pre-treatment than children with ARFID alone (N=63). Internal consistency was lower in the comorbid group. Conclusions: Findings suggest that NDDs are associated with less fear-based avoidance in ARFID and greater psychosocial impairment and highlight potential limitations in measuring ARFID symptoms among neurodiverse children using existing diagnostic tools.

P219

Comorbid States And Characteristics Associated With High Risk Of Avoidant/Restrictive Food Intake Disorder (Arfid) Among Adults
Emilie Southeran¹, Glenn Waller^1,2
¹University of Sheffield, Sheffield, United Kingdom, ²University of Warwick, Coventry, United Kingdom

Introduction This study examined the links of Avoidant/Restrictive Food Intake Disorder (ARFID) features with different physical and psychological characteristics. The aims were: To determine which correlates are most strongly related to ARFID when accounting for overlapping pathologies To determine which of two commonly used measures of ARFID (NIAS; PARDI-AR-Q) has stronger clinical validity in relation to comorbidity. Method The study was pre-registered, based on sample size analysis, and had ethical clearance. Mean age was 33.28 (SD = 11.77), 69% were female, and 85.5% were Caucasian. Participants completed measures of ARFID characteristics (NIAS; PARDI-AR-Q); height and weight; anxiety (GAD-7); depression (PHQ-9); intolerance of uncertainty (IUS-12); and autistic characteristics (AQ-10). Physical disorders, gender, sex and socio-economic status were all measured. Results Of the 124 with high risk of ARFID, the only sex-based difference was that women were more likely to report NIAS picky eating. Socio-economic background and comorbid physical conditions were largely unrelated to ARFID scores, but traumatic past experiences with food were associated with fear of consequences of eating. The PARDI-AR-Q was more strongly associated with psychological correlates (e.g., anxiety, depression, autism) than the NIAS. Conclusions The PARDI-AR-Q had stronger clinical validity than the NIAS. The two measures had similar, highly specific patterns of linkage to measures of comorbidity.

P220

Beyond The Ideal: How Body Appreciation Protects Young Adolescents From Dieting Pressures
Lien Goossens, Sandra Verbeken, Eva Van Malderen, Elisa Boelens
Ghent University, Gent, Belgium

Introduction: Dietary restraint appears in early adolescence in both girls and boys. Sociocultural models link media pressure and internalization of thin and muscular ideals to unhealthy eating attitudes, but not all adolescents are equally affected. Positive body image, particularly body appreciation, may buffer these effects. This study examined whether body appreciation moderates links between sociocultural influences and dietary restraint. Methods: A sample of 207 early adolescents (M age = 11.69; SD = 1.27; 51% girls) completed validated self-report measures of media pressure, internalization of thin and muscular ideals, body appreciation, and dietary restraint. Moderation analyses tested whether body appreciation weakens these associations. Results: Controlling for age and gender, media pressure and internalization of thin and muscular ideals were positively associated with dietary restraint. Body appreciation significantly moderated these relationships, weakening the associations between each sociocultural factor and dietary restraint. Conclusions: Body appreciation acts as a protective factor, reducing the impact of media pressures and beauty ideal internalization on dietary restraint. Promoting positive body image may help prevent unhealthy eating patterns in early adolescent girls and boys.

P221

Capturing Binge Eating In Early Adolescence: Comparing Parent And Child Reports In The Ccc2000 Cohort
Julia Freyer Martins Pereira, Else Marie Olsen, Nadia Micali
Center for Eating and feeding Disorders Research (CEDaR), Ballerup, Denmark

Introduction: Evidence on the development of binge eating (BE) and BE disorder in youth remains limited, despite high prevalence and peak onset during adolescence and young adulthood. This study aimed to examine the association between parent-reported and child self-report BE at ages 11-12 to assess the feasibility of harmonising BE measures for longitudinal analysis. A longer-term objective is to map longitudinal trajectories across ages 5-7, 11-12 and 16-17. Methods: Data were drawn from the CCC2000 study, a population-representative Danish birth cohort. BE scores were derived by combining relevant questionnaire items at ages 5-7 and 11-12 and standardise (z-scores) to facilitate comparability across informants and ages. Missing data at ages 11-12 (16.4-17.4%) were addressed using multiple imputation with predictive mean matching. Correlations were used to assess agreement between parent- and child-reported BE items. Results: Correlations between parent- and child-reported BE items at ages 11-12 were consistently weak (r=-0.004 to 0.16), indicating low agreement between informants. Data from later waves are pending and will be incorporated into future analyses and presented at the time of conference. Conclusions: BE in early adolescence may be inconsistently captured by parent reports, which highlights challenges in longitudinal assessment and underscores the importance of incorporating child-reported measures and additional waves to better characterise trajectories.

P222

The Association Between Child Emotional Abuse And Emotional Neglect With Disordered Eating Behaviours
Sonya Gill¹, Samantha Salmon¹, Melissa Kimber², Tamara Taillieu¹, Tracie.O. Afifi¹
¹University of Manitoba, Winnipeg, MB, Canada, ²McMaster, Hamilton , ON, Canada

Sub-clinical disordered eating behaviour (DEB) is common and, if left untreated, may progress to clinically significant conditions. Limited work has examined the relationship between emotional abuse (EA) and emotional neglect (EN), two prevalent forms of child maltreatment, and DEBs among adolescents. Among a sample of 14-17-year-olds in Manitoba, Canada, the specific aims of this work were to: 1) assess associations between EA, EN, any emotional maltreatment (EM; EA and/or EN), and DEBs; and 2) identify protective factors associated with lower likelihood of DEBs among adolescents with and without EA and/or EN histories. Data were drawn from the Well-Being and Experiences (WE) Study, a longitudinal intergenerational study conducted in Manitoba (Wave 1, 2017; N=1002). Overall, 24.5% reported any EM, 21.7% EA, and 13.3% EN. After adjusting for all child maltreatment types, only EM remained statistically significantly associated with DEBs for both sexes. Several protective factors were associated with increased odds of no DEBs (e.g. participating in school sports, being excited for the future, confiding in mother, feeling part of the school). Many possible clinically important protective factors were also identified (e.g. having a trusted adult in the community, volunteering, community involvement, motivation to help their community). Findings contribute to Canadian adolescent DEB research by examining EA/EN exposures and identifying potential protective factors.

P223

The Silent Struggle: High Prevalence Of Self-Harm And Suicidal Ideation In Brazilian Patients With Eating Disorders
Walter Santos Goncalves, Carlos Eduardo F Moraes, Carla Mourilhe, Maria Fernanda Moreira, Jose Carlos Appolinario
Obesity and Eating Disorders Group, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil

Introduction: Eating disorders (ED) are frequently comorbid with self-injurious and suicidal behaviors. However, clinical data in the Brazilian population remains scarce. This study assessed the prevalence of non-suicidal self-injury (NSSI) and suicidal ideation (SI) in a clinical sample from Rio de Janeiro Methods: Baseline data from an ongoing cohort at a specialized ED unit was analyzed. Participants (age >16) with AN, BN, or BED (SCID-I) were included. NSSI was assessed using the Functional Assessment of Self-Mutilation (FASM) and suicidal ideation by the Beck Suicidal Scale (BSS). Sociodemographic and psychopathology features were collected Results: The sample (n=20) comprised high-schooling cisgender women (AN=5; BN=7; BED=8). SI prevalence was 55% (Mean BSS=8.85) and significantly associated with employment (p<.04), anxiety-trait (p<.04), alexithymia (p<.007), burdensomeness (p<.003), and depression (p<.001). NSSI prevalence was 75% (30% moderate/severe; 45% mild) and associated with psychiatric medication use (p<.04), burdensomeness (p<.02), and depression (p<.03). Alexithymia, specifically difficulty identifying feelings, was correlated with NSSI severity. SI was significantly more prevalent in the NSSI group (p<.008) Conclusions: SI and NSSI are extremely prevalent in specialized ED care in Rio de Janeiro. These behaviors are linked to specific psychopathological traits, notably alexithymia and burdensomeness. Longitudinal data will be vital to clarify causal pathways

P224

Development And Co-Redesign Of A Clinical Quality Registry For Eating Disorders Down Under
Deborah Mitchison¹, Louise Carpenter¹, Kyra Bennett¹, Susan Byrne^2,3, Phillipa Hay^4,5, Gabriella Heruc^4,6, Sloane Madden^7.8, Sian McLean⁹, Marion Roberts^10,11, Jack Tame¹, Tracey Wade¹²
¹University of Technology Sydney, Sydney, Australia, ²Western Australia Department of Health, Perth, Australia, ³Richardson Group, Perth, Australia, ⁴Western Sydney University, Sydney, Australia, ⁵ReCentre, Waratah Private Hospital, Sydney, Australia, ⁶Appetite for Change, Sydney, Australia, ⁷Ramsay Health Care, Sydney, Australia, ⁸University of Sydney, Sydney, Australia, ⁹La Trobe University, Melbourne, Australia, ¹⁰University of Auckland, Auckland, New Zealand, ¹¹Nurture Psychology, Auckland, New Zealand, ¹²Flinders Institute for Mental Health and Wellbeing, Adelaide, Australia

Introduction
Despite their value for clinical decision-making, real-world research, and policy, mental health clinical quality registries (CQRs) remain rare. This presentation outlines the co-redesign of the Australia and New Zealand CQR for the Treatment of Eating Disorders (EDs) (TrEAT Registry), which collates and reports back on clinical data across all levels of ED care. Methods
A co-designed, mixed-method, multi-study approach was used, including focus groups with TrEAT Registry end users (n=20) to identify challenges, facilitators, and potential solutions; a survey of the local ED community to identify desired CQR features (n=230); and two co-design workshops to develop recommendations based on the focus group and survey findings. Data were analysed using thematic and descriptive methods. Results
Strong support was found for existing features, including a brief set of self-report measures, a flexible minimum dataset, continuous feedback to clinics, governance by a diverse advisory committee with lived experience members, and capacity for embedded research trials. New or enhanced features receiving strong support included patient experience and carer outcome measures, public annual reporting, and support to expand clinic coverage. Mixed support was observed regarding the measurement of weight and use of session-by-session measures in outpatient settings. Conclusions
Findings informed a set of recommendations for registry redesign, which will be discussed.

P225

Disordered Eating Patterns In Boys �" Population Data From Norway And The Uk
Nora Trompeter¹, Kirsti Kvaløy², Trine Tetlie Eik-Nes², Nadia Micali^1,3
¹Great Ormond Street Institute of Child Health, UCL, London , United Kingdom, ²Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway, ³Center for Eating and feeding Disorders Research, Mental Health Center Ballerup, Copenhagen University Hospital – Mental Health Services CPH, Copenhagen, Denmark

Introduction: Disordered eating in adolescent boys remains poorly understood. This study examined the prevalence and socio-demographic correlates of disordered eating in boys. Methods: Data were from the Avon Longitudinal Study of Parents and Children based in the UK (n = 2744), and The Young-HUNT Study, a population-based cohort of adolescents in Norway (n = 1851). Adolescents completed self-report measures about disordered eating, which were harmonised to combine cohorts. Results: Disordered eating was common among adolescent boys. 20.6% reported loss-of-control eating, 15.5% embarrassment around binge eating, 13.1% attempted to lose weight, 2.9% engaged in purging, and 0.9% used laxatives. 72.8% of boys reported trying to build muscle, and 0.2% used steroids. Discussion: Findings showed that disordered eating was common among boys, with many reporting muscle building behaviours. Results highlight that many traditional disordered eating indicators may not represent boys adequately.

P226

Emergence Of Body Dissatisfaction And Disordered Eating From Ages 8 To 12: Longitudinal Evidence From The Growing Up In New Zealand Cohort
Tom Woodd, Cameron Grant, Marion Roberts
University of Auckland, Auckland, New Zealand

Eating disorders are an increasing global health concern, with early symptoms emerging in preadolescence. Longitudinal research in this age group is limited. This study examined the development of body dissatisfaction and its associations from childhood to early adolescence. Data were drawn from the Growing Up in New Zealand study, a nationally representative longitudinal birth cohort study. Children self-reported current and ideal body size using the Collins figural rating scale at ages 8 (N = 4922) and 12 (N = 4566), generating a body dissatisfaction score. At age 12, participants also reported dieting (N = 4376) and mealtime restriction (N = 4428). Longitudinal changes and associations with anthropometric, mental health, social, media, and weight-related variables were examined. At ages 8 and 12, nearly half of children reported body dissatisfaction, with a consistent preference for smaller body size. Gender differences emerged by age 12, with boys reporting greater satisfaction than girls and gender questioning youth. Higher weight-for-age, child weight/body concerns, and maternal weight perceptions predicted increased dissatisfaction over time. While most children had not dieted, nearly 40% reported mealtime restriction. Body dissatisfaction is common and emerges early, with identifiable risk factors across individual and familial domains. Findings highlight the importance of early, developmentally informed prevention efforts targeting body confidence and family food culture.

P227

Characterization Of Acute Eating Disorder Presentations: A Cross-Sectional Multicenter Analysis Of Pediatric Emergency Department Visits
Vanessa Burd, Kendrin Sonneville, Suzanne Dooley-Hash, James Cranford
University of Michigan, Ann Arbor, MI, United States

The purpose of this study is to characterize the prevalence of secondary medical diagnoses among adolescents with eating disorders presenting to the emergency department utilizing a cross-sectional, multicenter design. Using the Pediatric Health Information System dataset, we measure the overall prevalence of restrictive eating disorders among pediatric patients presenting to the emergency department as well as classifying co-occurring medical diagnoses and stratifying inpatient admission rates by these diagnoses. Notably, our data includes emergency department prevalence of ARFID in our analysis. We also examine factors associated with ICU admissions from the emergency department in the pediatric eating disorder population. Analysis is conducted on a dataset spanning 2023-2025 across approximately 45 pediatric emergency departments in the United States. This cross sectional analysis builds off of previous single center reviews of co-occurring medical diagnoses to better quantify how complexities in patient presentation affect admissions for eating disorders and their associated medical complications to improve system-wide generalizability and to better determine outcomes amongst medically complex patients.

P228

Serum Leptin And Thyroid Levels In Hospitalized Patients With Severe Eating Disorders
Simar Singh¹, Dennis Gibson^2,3, Andrea Garber⁴, Marina Foster², Amy B. Stein², Philip S. Mehler^3,5
¹Department of Psychiatry and Behavioral Sciences University of California, San Francisco, , San Francisco, CA, United States, ²ACUTE Center at Denver Health, Denver, CO, United States, ³Department of Medicine University of Colorado School of Medicine, Denver, CO, United States, ⁴Department of Pediatrics University of California, San Francisco, San Francisco, CA, United States, ⁵Eating Recovery Center, Denver, CO, United States

Introduction: Leptin and thyroid hormones (THs) are interrelated regulators of energy homeostasis, yet their within-subject trajectories during nutritional rehabilitation in severe restrictive eating disorders (EDs) remain poorly understood. Methods: Data from 62 adult inpatients were analyzed. Serial blood draws measuring leptin, T3, T4, and reverse T3 (rT3) were obtained at admission, at each 1.5 kg/m² increase in BMI, and at discharge. Receiver operating characteristic curve analyses identified optimal BMI thresholds for clinically abnormal hormone levels, and multilevel models examined hormonal trajectories over BMI change. Results: At admission, leptin was undetectable in 74.2% of patients, T3 was low in 96.8% of patients, T4 was normal in all patients, and rT3 was low-to-normal in most patients. By discharge, leptin remained undetectable in 24.2% of patients, and T3 normalized in only 22.6%. No BMI thresholds were clinically significant for identifying abnormal lab levels. Leptin increased linearly with BMI gain, while THs demonstrated a biphasic pattern: T3 rose exponentially before plateauing, while T4 and RT3 declined sharply before rebounding, all around +2.0kg/m². Conclusions: THs appear to normalize in quick response refeeding, while leptin recovery is proportional but prolonged. These findings suggest complementary clinical utility: THs may monitor acute refeeding progress, while leptin may better reflect longer-term nutritional rehabilitation in restrictive EDs.

P229

Enhancing The Uptake Of The Canadian Practice Guidelines For Treating Children And Adolescents With Eating Disorders: An Implementation Study
Jennifer Couturier¹, Maria Nicula¹, Ethan Nella¹, Tovah Yanover¹, Tanya Sharma¹, Florence Deng¹, Melissa Kimber¹, Jennifer Coelho², Gina Dimitropoulos³, Gail McVey⁴, Mark Norris⁵, Nicole Obeid⁵, Natasha Johnson¹, Cheryl Webb¹, Melissa Brouwers⁵
¹McMaster University, Hamilton, ON, Canada, ²University of British Columbia, Vancouver, BC, Canada, ³University of Calgary, Calgary, AB, Canada, ⁴University of Toronto, Toronto, ON, Canada, ⁵University of Ottawa, Ottawa, ON, Canada

Introduction: This study engaged partners (healthcare providers, youth with lived experience, and caregivers) to assess awareness, use, and perceived impact of practice guidelines for eating disorders before and after an implementation strategy.
Methods: Online surveys were disseminated to partners across Canada at pre-implementation to assess the awareness, use, and perceived impact of the guidelines. Following dissemination of an implementation strategy (including guideline synopses, a dedicated website, and educational videos), a post-implementation survey was distributed to assess changes in these outcomes.
Results: Ninety-nine participants completed the pre-implementation survey, while 60 of these individuals completed the post-implementation survey. Mean awareness (2.13 to 2.93, p<0.001), use (1.90 to 2.35, p<0.007), and perceived impact (1.95 to 2.33, p<0.037) of the guidelines all increased significantly. A subgroup analysis revealed that these improvements were primarily observed among youth with lived experience, with no significant changes among healthcare providers or caregivers. Qualitative feedback was positive, highlighting accessibility, clarity, and multi-format delivery, alongside suggestions to improve engagement and dissemination.
Conclusions: Guideline awareness, use, and perceived impact improved following our implementation strategy. Multi-format methods may increase guideline uptake, though additional strategies may be needed to enhance engagement across partner groups.

P230

Developing And Testing A Fidelity Tool To Evaluate Early Intervention Implementation In Eating Disorder Services
Lucy Hyam¹, Lucy Gallagher¹, Giulia Di Clemente², Eóin Killackey^3,4,5, Danielle Glennon², Jessica Griffiths², Regan Mills², Jessica Wilkins¹, Muhammad Ahmed², Zoe Tsivos⁶, Sarah Macnab⁷, Ben Kirton⁸, Emily Palmer⁹, Karina Allen^1,2, Ulrike Schmidt^1,2
¹ Centre for Research in Eating and Weight Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom, ² Eating Disorders Outpatients Service, Maudsley Hospital, South London and Maudsley NHS Foundation Trust, London, United Kingdom, ³ Orygen, Melbourne, Australia, ⁴ Centre for Youth Mental Health, The University of Melbourne, Melbourne, Australia, ⁵ Centre for Population Health, Helse-Bergen HF, Haukeland Universitetssjukehus, Bergen, Norway, ⁶The Willows Centre for Health, Greater Manchester Mental Health NHS Foundation Trust, Salford, United Kingdom, ⁷Wiltshire Community Eating Disorders Service, Oxford Health NHS Foundation Trust, Wiltshire, United Kingdom, ⁸Oxfordshire Adult Community Eating Disorders Service, Oxford Health NHS Foundation Trust, Oxford, United Kingdom, ⁹ Sussex Eating Disorder Service, Sussex Partnership NHS Foundation Trust, Worthing, United Kingdom

Introduction: First Episode Rapid Early Intervention for Eating Disorders (FREED) is an early intervention model for young people with recent‐onset eating disorders. We present the development of a FREED/early intervention implementation fidelity tool and its initial evaluation, exploring feasibility and patterns of fidelity in eating disorder services in England. Methods: A 35-item fidelity tool was drafted via an iterative consultation process, covering two components: (1) rapid access to the service and (2) adherence to the early intervention care package. The tool was tested longitudinally in one service and then cross-sectionally in six services, using routine data and staff interviews. Two independent raters scored all items, and interrater reliability was assessed. Results: Across both studies, the tool was feasible and time efficient with high interrater agreement. Rapid access scores, which depend on staffing levels, varied widely across services (20-87%), whereas care package delivery scores showed consistent medium-high fidelity (72-82%). Conclusions: This is the first fidelity measurement tool for early intervention eating disorder services. It shows feasibility, simple administration, and strong interrater agreement. Pilot testing highlights areas of high fidelity and areas requiring support. Future work should refine the tool and test it further. Delivery of rapid access targets depends on appropriate investment into services.

P231

Development Of Recommendations To Improve The Identification And Management Of Binge Eating Disorder And Bulimia Nervosa In Primary Care In The Uk: A Qualitative InvestigatioN
Stella Kozmér^1,2, Jane R. Smith¹, Alex Burns^1,3, Natalia S. Lawrence⁴, Samantha B. van Beurden¹
¹University of Exeter Medical School, University of Exeter, Exeter, UK, Exeter, United Kingdom, ²Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom, ³Three Spires Medical Practice, Truro, Cornwall, United Kingdom, Truro, United Kingdom, ⁴Department of Psychology, University of Exeter, Exeter, UK, Exeter, United Kingdom

Background: Our previous review highlighted that limited knowledge and understanding of Binge Eating Disorder (BED) and Bulimia Nervosa (BN) amongst primary care healthcare professionals (HCPs) may negatively impact their identification and management. Our previous national survey also highlights limited active identification in practice and significant differences in the management of BED/BN. Hence, we aim to identify strategies to improve the identification and management of BED/BN in UK primary care. Methods: Individual interviews and focus groups were conducted in a primary care setting with 26 participants. The sample comprised primary care HCPs and individuals with lived experience (LE) of BED/BN aged 16+ years. Reflective deductive-inductive thematic analysis was used to analyse the data. Findings: To improve the care of BED/BN in primary care, relevant education needs to be provided to HCPs, patients, their families and the public, a suitable and accurate screening tool and functional screening pathways need to be developed, current treatment and referral pathways must be improved by simplifying the referral process and provide interim management options for patient, and that guidelines must be clear, specific, and co-designed to enable the implementation of all the abovementioned suggestions. Conclusion: Understanding good practice for other conditions within the UK and for BED/BN in other countries is important to enhance the feasibility of implementing our recommendations.

P232

Maladaptive Weight-Related Compensatory Behaviors Among Individuals Undergoing Metabolic And Bariatric Surgery
Deborah Lynn Reas¹, Selma Øverland Lie¹, Tom Mala^2,3, Ingela Lundin-Kvalem⁴
¹Regional Department for Eating Disorders, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway, ²Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway, ³Department of Gastrointestinal Surgery and Paediatric Surgery, Oslo University Hospital, Oslo, Norway, ⁴Department of Psychology, Faculty of Social Sciences, University of Oslo, Oslo, Norway

Objectives: Little is known about maladaptive, weight-related compensatory behaviors (CB) among individuals undergoing metabolic and bariatric surgery (MBS). We examined key features of restrictive eating disorders, including fasting (> 8 hours), self-induced vomiting, and misuse of laxatives and diuretics prior to and 10 years following MBS. Methods: 193 participants (76.6% F) aged 44.8 (9.5) years with a BMI of 42.9 (5.4) underwent MBS (94.3% Roux-en-Y). We examined the frequency of weight-related CB at pre-surgery and 10 years after MBS and classified participants as those who had (1) never, (2) continued, 3) remitted, or (4) developed CB. Results: 42% reported at least one weight-related CB prior to surgery. Fasting was the most common method (26.9%), followed by diuretics (17.6%), laxatives (11.9%) and self-induced vomiting (8.3%). At 10 years post-op, 13.3% reported at least one CB. Over the follow-up period, 55.4% had never engaged in any CB, 31.1% remitted, 9.8% continued, and 3.6% reported de novo CB. There were no pre- or post-operative factors associated with remittance, continuance, or development of CB. Conclusions: Self-induced vomiting, diuretic and laxative misuse, and fasting were reported by approximately 40% prior to MBS but declined substantially a decade later. Improved awareness and assessment of maladaptive, weight-related compensatory behaviors are recommended within surgical populations, especially prior to MBS, to increase awareness and knowledge about potential risks.

P233

Momentary Instability Or Dispositional Dysregulation? Predicting Eating Restriction From Ema-Derived Affect Lability And Trait Emotion Dysregulation
Line Wisting¹, Ingrid Funderud¹, Joseph Wonderlich^{2, 3}, Kristin Stedal¹
¹Oslo University Hospital, Regional Dept. for Eating Disorders, Oslo, Norway, ²Sanford Research, Division of Biobehavioral Research, Fargo, ND, United States, ³University of North Dakota School of Medicine and Health Sciences, Department of Psychiatry, Grand Forks, ND, United States

Objective: Emotion dysregulation has been implicated as a potential mechanism of eating disorders (ED), yet it remains unclear how trait dysregulation relates to momentary affect lability and restriction. This study examined convergent and predictive validity of ecological momentary assessment (EMA) indices of affect lability, including mean square successive difference (MSSD) and probability of acute change (PAC), across negative affect, valence, and arousal in ED. Method: N=33 women with ED completed daily EMA ratings of affect and restriction over a 2-week period and baseline self-report emotion dysregulation. Convergent validity was evaluated using correlations, and predictive validity was examined using negative binomial regression models predicting restriction. Results: Negative affect instability was associated with emotion dysregulation (MSSD r = .37; PAC r = .36). Greater negative affect instability was associated with lower restriction. In contrast, emotion dysregulation was positively associated with restriction in the MSSD model but was attenuated in the PAC model. Indices based on arousal and valence were not significant predictors. Conclusions: EMA-derived instability in negative affect shows partial convergence with trait dysregulation. Restriction was not associated with affect lability but coincided with relatively lower momentary variability in negative affect. This highlights the importance of distinguishing trait emotional difficulty from dynamic affective processes in ED.

P234

Does Perception Of Meal Portion Size Normalize Long-Term In Anorexia Nervosa?
Veronica Attanasio, Lisa Guth, Gabriella F. Milos
University Hospital of Zurich, Department of Consultation-Liaison Psychiatry and Psychosomatic Medicine, Zurich, Switzerland

Introduction: An overestimated perception of meal portion size, associated with the uncertainty regarding the food amount that should be consumed, are known features of anorexia nervosa (AN). This study examines whether portion size perception normalizes over the long-term following treatment by assessing changes in estimations of AN patients from admission to inpatient treatment, to discharge and at long-term, and by comparing these changes between patients with a long-term positive and a negative outcome, as well as with healthy individuals. Methods: Meal portion size perception was assessed using a visual analogue scale at admission, discharge and 1-4 years after inpatient treatment at the Center for Eating Disorder of the University Hospital of Zurich. Results: Patients overestimated meal portion size at admission. The overestimation partially improved with treatment and normalized long-term in patients with a positive long-term outcome. Patients with a negative long-term outcome continued to overestimate portion sizes. Conclusion: This study showed that the ability to estimate portion sizes could normalize in the course of treatment and in the long-term outcome, suggesting a normalization of the perception and indicating that uncertainty regarding food amount to be consumed should be addressed as part of treatment.

P235

Associations Between Impulsive Phenotypes And Loss Of Control Eating During Early Pregnancy
Lydia B. Brown¹, Riley J. Jouppi¹, Rebecca L. Emery Tavernier^2,3, Michele D. Levine¹
¹University of Pittsburgh, Pittsburgh, PA, United States, ²Weitzman Institute, Moses Weitzman Health System, Washington, DC, United States, ³University of Minnesota Medical School, Duluth, MN, United States

Introduction: The perinatal period is linked to increased risk for loss of control eating (LOC). Impulsivity is associated with LOC outside of pregnancy, but there is limited research on impulsivity and prenatal LOC. Thus, we examined concurrent associations between impulsive phenotypes and prenatal LOC. Methods: Pregnant individuals (N=312) with prepregnancy BMI≥25 were assessed in early pregnancy (M[SD]_{gestational age}=13.6[2.7] weeks). Impulsivity was measured using trait questionnaires (Barratt Impulsiveness Scale [BIS-11], UPPS-P Negative Urgency) and behavioral tasks (Go/No-Go, Delay Discounting Tasks; Stroop Color-Word, Wisconsin Card Sorting Tests). LOC, measured using the Eating Disorder Examination-Questionnaire, was dichotomized (0=absent, 1=present). Logistic regression models estimated associations between impulsivity and prenatal LOC, controlling for maternal and gestational ages. Results: Questionnaire measures of trait impulsivity (BIS-11: OR=1.71, 95% CI [1.33, 2.22], p<.001) and negative urgency (UPPS-P: OR=1.89, 95% CI [1.47, 2.48], p<.001) were significantly associated with higher odds of prenatal LOC. Behavioral task measures were not significantly associated with prenatal LOC (ps>.40). Conclusions: Impulsivity was associated with increased risk for prenatal LOC, but associations differed according to how impulsivity was operationalized. Trait measures may be more effective at identifying individuals at risk for prenatal LOC, informing perinatal health promotion efforts.

P236

Parents As Role Models: An Experimental Study On The Influence Of Parents&Rsquo; Self-Related Body Talk On Children&Rsquo;S Body Image.
Jolien De Coen, Elisa Boelens, Eva Van Malderen, Ellen Van Moere, Sandra Verbeken, Lien Goossens
Faculty of Psychology and Educational Sciences, Department of Developmental, Personality and Social Psychology, Ghent University, Belgium , Ghent, Belgium , Ghent, Belgium

Introduction. Research suggests that parents may influence the development of body satisfaction and body talk in their children by modelling their own self-related body talk. However, little is known about how parents’ positive body talk affects children’s self-related body talk and body image. This study examined the impact of parents’ functionality‑focused versus appearance‑focused comments on children’s body‑related comments and body satisfaction. Methods. An experimental design was conducted among 61 children (aged 10–12 years) and one of their parents, including 46 daughter–mother and 15 father–son dyads. Children completed an individual mirror exercise, followed by a joint parent–child mirror exercise. In both tasks, they described what they liked or disliked about a specific body part and rated their satisfaction with that body part. Results. When exposed to parents’ positive functionality‑focused comments, children increased their own functionality‑focused comments during the joint exercise compared to the individual exercise. No decrease in appearance‑focused comments or increase in body satisfaction was found. Parents’ appearance‑focused comments did not affect children’s body talk or body satisfaction. Conclusions. These findings indicate that parents may help foster a functionality‑focused view of the body in their children. The results highlight the value of involving parents in body image prevention and intervention programs.

P237

Investigating The Relationship Between Alexithymia And Disordered Eating
Maria Garland^{1, 2}, Julian Baudinet³, Rich Bostwick², Fenella Gill^{1, 2}, Elizabeth Swann¹, David Preece²
¹CAMHS Eating Disorder Service, Perth, Australia, ²Curtin University, Perth, Australia, ³South London and Maudsley Child and Adolescent Eating Disorder Service, London, United Kingdom

Background: Alexithymia is a transdiagnostic risk factor for psychopathology and is characterised by difficulties in emotion identification and processing. The relationship between alexithymia and symptoms of eating disorders, is well known; however, the underlying mechanisms remain unclear. Method: This study examined associations between alexithymia facets and eating disorder symptoms across a university student sample (N = 827) and a general population sample (N = 484) using hierarchical regressions, and latent profile analysis.
Results: Eating disorder symptoms were most consistently associated with difficulties appraising emotions, whereas externally oriented thinking showed weaker and less consistent relationships. Regression analyses revealed valence-specific patterns: difficulties appraising positive emotions were the most consistent predictor in the student sample, whereas difficulties appraising negative emotions were most consistent in the general population sample. Latent profile analysis identified four profiles across both samples characterised by distinct emotional appraisal patterns and differing levels of eating disorder symptoms.
Significance: These findings indicate that disordered eating symptoms are linked to specific emotional appraisal difficulties rather than a single, uniform alexithymia profile, highlighting the potential value of targeting emotional appraisal processes in treatment.

P238

An Implicit Association Test-Like Task For Assessing Self-Objectification In Healthy Young Women
Yumi Hamamoto^1,2,3, Soichiro Kan^4,, Motoaki Sugiura^3,5
¹Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai, Japan, ²Research Institute of Electrical Communication, Tohoku University, Sendai, Japan, ³Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan, ⁴School of Medicine, Sendai, Japan, ⁵International Research Institute of Disaster Science, Tohoku University, Sendai, Japan

Body image dissatisfaction is a risk factor for eating disorders, and self-objectification contributes to it. However, questionnaires to measure self-objectification are susceptible to social desirability bias. Thus, we tested an objective index for self-objectification using a task inspired by the Implicit Association Test. Fifty-four women (21.2 ± 1.98 years) saw a photo (self or object) and a word (human- or object-related) and classified the cued stimulus as human or object. Faster reaction time (RT) were assumed to reflect stronger photo-word associations. Body shape questionnaire (BSQ) assessed body image dissatisfaction. For object photos, RTs were faster with object- than human-related words (p <.05). We therefore used object-photo/object-word RT as a strong anchor and object-photo/human-word RT as a weak anchor, then used Bayesian analyses to evaluate associations between self-photos and both word types. Self-photos were strongly associated with both word types, which were comparable to or stronger than the strong anchor (Pr[μ <35 ms] > .99). RTs were also comparable across word types, or slightly faster for object-related words (Pr[μ <35 ms] > .99). Faster responses to self-photo/object-word than to self-photo/human-word pairs tended to be associated with higher BSQ scores (r = .25, p = .07). These findings suggest this task may provide an objective self-objectification index, and that even healthy women may already strongly associate themselves with objects.

P239

Weight Bias Internalization And Disordered Eating Across The Perinatal Period
Shruti Kinkel-Ram¹, Christine Call¹, Caroline Christian¹, Shannon Donofry², Marquis Hawkins³, Riley Jouppi^1,3, Michele Levine¹
¹University of Pittsburgh School of Medicine, Pittsburgh, PA, United States, ²RAND, Pittsburgh, PA, United States, ³University of Pittsburgh, Department of Psychology, Pittsburgh, PA, United States

Introduction. Pregnant and postpartum individuals frequently encounter weight stigma, yet perinatal populations remain underrepresented in research on weight bias internalization (WBI) and disordered eating. This study examined WBI and disordered eating symptoms longitudinally across pregnancy and postpartum. Methods. Participants (N=312) in a maternal health trial completed the Weight Bias Internalization Scale, Eating Disorder Examination Questionnaire-IV, and demographics surveys at 12–14 and 34–36 weeks’ gestation and 6 and 12 months postpartum. Multiple regressions tested whether WBI predicted later eating, shape, and weight concerns across pregnancy and postpartum, adjusting for gestational/postpartum age, baseline weight, and treatment sequence. A mixed-effects model tested change in WBI over time. Results. WBI in early pregnancy and early postpartum significantly predicted eating, shape, and weight concerns in late pregnancy (βs=0.53–0.72, ps<.001) and late postpartum (βs=0.33–0.74, ps<.02), respectively. WBI also varied significantly over time, F(3,59.81)=3.22, p=.029. Estimated marginal means showed that WBI decreased from early to late pregnancy and increased postpartum; only the early-to-late pregnancy decrease was significant (p=.041). Conclusions. WBI was associated with disordered eating cognitions across pregnancy and postpartum and varied across the perinatal period. These findings highlight WBI as a potentially modifiable intervention target in perinatal care.

P240

Temperament And Character Profiles In Adolescents With Anorexia Nervosa And Their Parents
Dunja Mairhofer, Michael Zeiler, Julia Klang, Stefanie Truttmann, Michalea Mitterer, Gudrun Wagner, Andreas Karwautz
Department of Child and Adolescent Psychiatry, Medical University of Vienna, Vienna, Austria

Temperament and character traits in patients and their parents have been discussed as potential factors in the development and maintenance of anorexia nervosa This study aimed to characterize personality traits in adolescents with anorexia nervosa and their parents, and to examine their associations with ilness severity and treatment outcome. A total of 100 adolescents with anorexia nervosa (aged 11-17 years, 88% restrictive subtype) in inpatient treatment, as well as 85 mothers and 64 fathers, were assessed using the Temperament and Character Inventory (TCI/J-TCI). Eating disorder pathology was evaluated using the Eating Disorder Examination Interview (EDE), the EDE-Q, the EDI-2, and body mass index (BMI). Patients showed higher harm avoidance, cooperativeness, and persistence, and lower novelty seeking and self-directedness. A cluster analysis identified an "unfavorable" personality profile associated with greater severity and longer inpatient stay. Mothers showed lower novelty seeking, fathers higher self-directedness and lower cooperativeness and self-trancendence. Correlations between adolescent and parental traits were weak. Comprehensive personality assessment in adolescents with anorexia nervosa may provide valuable insights into illness severity and expected treatment course. Patients with an "unfavorable" personality profile may benefit from more intensive and individualized therapeutic approaches to reduce the risk of chronicity and relapse.

P241

A Sequential Pathway From Weight Stigma To Eating Disorder Symptoms Via Low Interoceptive Trust And Central Sensitization
Janell L. Mensinger, Maria F. Carriel Sarmiento
Nova Southeastern University, Fort Lauderdale, FL, United States

The association between weight stigma (WS) and eating disorder symptoms (EDS) is well known; however, the mechanisms that underlie this relationship remain unclear. This study tested a preliminary integrative model in which WS relates to EDS sequentially through interoceptive sensibility (MAIA) factors (trusting, not distracting, not worrying) and central sensitization (CS)—an amplification of pain signals in the central nervous system. In a large U.S. census-matched sample (N=2000, 54% women, 52% non-Hispanic White; M_age=44; SD=15.6), we used the Process (v4.2) macro (model 80) to estimate serial indirect effects with percentile bootstrapped 95% confidence intervals. Participants completed measures of WS, EDS, CS, and interoception using the recently validated invariant MAIA-short form. Twenty-seven percent of the total effect (B=0.61, SE=0.03; 95% CI=0.56–0.66) between experiences of WS and EDS was explained by the total indirect effect (TIE) (B=0.16; SE=0.01; 95% CI=0.14–0.19). CS emerged as the predominant indirect pathway, accounting for 35% of the TIE, alongside trusting (30% of TIE). Though all reductions in MAIA factors were linked to increases in CS and EDS (ps<.001), the trusting to CS pathway was primary (13% of TIE). These results identify novel mechanisms linking interoceptive deficits and CS as key mediators through which weight stigma may exacerbate disordered eating, highlighting potential targets for further research and intervention, especially in higher weight EDs.

P242

The Ozempic Era: Weight, Food And Community Storytelling On Reddit
Holly Pedersen^1,2, Courtney P. McLean³, Sharon L. Grant¹, Kathleen de Boer^1,2
¹Department of Psychological Sciences, Melbourne, Australia, ²Centre for Mental Health and Brain Sciences, Melbourne, Australia, ³Monash University, Melbourne, Australia

Introduction: Despite widespread use of glucagon-like peptide-1 receptor agonists (GLP-1), little is known about who is using them in the real-world. Additionally, there is limited insight regarding the experience of weight and diet changes in GLP-1 users. Thus, the aim of this study, was to examine the anthropomorphic profiles and discourse regarding weight and diet on GLP-1 related subreddits.
Methods: We conducted a retrospective analysis of publicly available posts and comments from GLP-1 subreddits. Demographic attributes and weight-related information were extracted using machine learning models. Thematic analysis was used to analyse a subset of posts. Results: Among authors with available data, the median age was 45 years and 71.1% identified as female. Where BMI was available, the median starting BMI was 34.7 kg/m² and median goal BMI was 24.3 kg/m², on average authors aimed to lose 29.9kgs. Preliminary thematic analysis indicates that users experience unwanted weight fluctuations, plateaus and fear weight regain. Analysis regarding dietary patterns is forthcoming.
Conclusions: Our study provides insight into the real-world use of GLP-1s and highlights some of the attitudes and experiences regarding weight and dietary changes during GLP-1 use. Findings support the need for clearer clinical guidance and regulation to manage expectations, and the psychology of weight loss drugs.

P243

Critically Revisiting The Psychometric Properties Of The Eating Disorder Examination Questionnaire And Its Short Forms: Is It Time To Move On?
Rafael M. A. da Rocha^1,2,3, Andrea Phillipou^2,3,4,5, Erica Neill^2,3,4, Stephanie Miles^2,3,5
¹University São Francisco, Campinas, Brazil, ²Orygen, Parkville, Melbourne, Australia, ³Centre for Youth Mental Health, The University of Melbourne, Melbourne, Australia, ⁴Parkville Youth Mental Health & Wellbeing Service, Melbourne, Australia, ⁵Department of Psychological Sciences, Swinburne University of Technology, Melbourne, Australia

The Eating Disorder Examination Questionnaire (EDE-Q) is the most widely used self-report measure of eating disorder symptoms, despite longstanding concerns about factorial instability, construct redundancy, and local item dependence. Brief versions have been proposed to address these limitations, yet it remains unclear whether they represent psychometric advances. We critically re-examined the internal structure and validity evidence of the full EDE-Q and its short forms in 772 Australian women. Dimensionality was investigated using bootstrap Exploratory Graph Analysis (EGA), followed by Confirmatory Factor Analysis. At both latent variable and item levels, we examined discriminant validity through inter-correlations and associations with external variables, and assessed classification accuracy for self-reported anorexia nervosa. Across versions, EGA yielded more parsimonious structures than originally proposed, collapsing highly correlated factors. Original models retaining two-item factors and doublets showed better fit but limited discriminant validity, suggesting that apparent multidimensionality may reflect statistical accommodation of local dependence rather than distinct constructs. Global scores were highly correlated (r>.90) and showed comparable classification accuracy across versions. Although brief forms reduced length, they did not meaningfully resolve core structural weaknesses. We therefore emphasize the need for new measures grounded in contemporary psychometric best practices.

P244

Dietary Restraint And Negative Affect As Potential Proximal Predictors Of Ultra-Processed Food Consumption In Adolescent Girls With Binge Spectrum Eating Disorders
Laura Rubino¹, Laura D'Adamo¹, Stephanie Manasse²
¹Department of Psychological and Brain Sciences, Drexel University , Philadelphia, PA, United States, ²Center for Healthcare Delivery Science, Nemours Children’s Health, Wilmington, DE, United States

Ultra-processed foods (UPFs) may uniquely contribute to the maintenance of loss-of-control eating (LOC) in adolescents due to their impact on reward dysregulation. Examining momentary drivers of UPF intake among those with LOC may inform interventions to reduce UPF intake, which in turn could reduce LOC. We examined dietary restraint and negative affect (NA) as proximal predictors of UPF intake in an ecological momentary assessment (EMA) study of adolescent girls (N=58) with binge spectrum eating disorders. Dietary restraint, NA, and UPF intake were assessed 5x/day for 21 days. We conducted generalized mixed-effect models to test if mean prior-day, same-day, and momentary dietary restraint and NA predicted UPF intake (binary variable), with random intercepts for participants. Higher daily within-person (OR=1.52, p=.016) and between-person restraint (OR=1.56, p=.026) were associated with greater same-day odds of UPF intake, but effects became non-significant after adjusting for LOC presence. Higher daily within-person NA (OR=1.21, p<.001) was associated with greater same-day odds of UPF. Higher momentary within-person NA was associated with increased odds of UPF consumption at the next survey (OR=1.39, p=.036). No other tests were significant. Future research should investigate the potential affect regulating role of UPF intake and how NA and dietary restraint differentially impact food choice (e.g., UPF or non-UPF) versus the type of eating episode (e.g., LOC versus not).

P245

Within-Person Links Between Exercise And Momentary Emotion Regulation Strategies In Anorexia Nervosa: Preliminary Results Of An Ecological Momentary Assessment
Johann P. Summ¹, Michael Hollauf², Alexander Heimbeck², Sandra Schlegl^2,3, Ulrich Voderholzer^2,3,4, David R. Kolar¹
¹Department of Psychology, University of Regensburg, Regensburg, Germany, ²Schoen Clinic Roseneck, Prien am Chiemsee, Germany, ³Department of Psychiatry and Psychotherapy, LMU University Medicine , Munich, Germany, ⁴Department of Psychiatry and Psychotherapy, Albert-Ludwigs-University Freiburg, Freiburg, Germany

Compulsive exercise is highly prevalent in anorexia nervosa (AN) and linked to short-term affective benefits. It remains unclear whether everyday exercise merely provides short-term affective improvement within a maladaptive regulation cycle or if exercise is also associated with a momentary shift in emotion regulation (ER) strategies. Sixteen patients with AN completed a smartphone-based ecological momentary assessment for one week. At each beep, participants reported whether they had exercised since the previous beep and rated momentary ER strategies; when exercise was reported, they additionally rated exercise compulsiveness. Adaptive and maladaptive ER composites were computed. Linear mixed models (N = 448 beep-level observations) separated within- and between-person effects of exercise and accounted for autocorrelation. At the within-person level, exercise intervals were associated with slightly higher adaptive ER (b = 2.74, SE = 1.55, p = .079) and showed no clear association with maladaptive ER. In exploratory follow-up analyses restricted to exercise intervals, higher exercise compulsiveness was associated with lower adaptive (b = -4.31, SE = 1.62, p = .008) and higher maladaptive ER (b = 3.37, SE = 1.63, p = .040). These preliminary results provide no robust evidence that everyday exercise per se is associated with more adaptive or less maladaptive momentary ER in AN; however, more compulsive exercise may be linked to less adaptive and more maladaptive momentary ER.

P246

Alexithymia And Emotion Regulation In Parents Of Patients With Anorexia Nervosa: Results From A Longitudinal Intervention Study
Stefanie Truttmann¹, Jessica Jerabek³, Julia Klang¹, Helene Krauss¹, Konstantin Kopp¹, Veronica Seitl², Gudrun Wagner¹, Andreas Karwautz¹, Michael Zeiler¹
¹Department for Child and Adolescent Psychiatry, Eating Disorders Unit, Medical University of Vienna, Vienna, Austria, ²Medical University of Vienna, Vienna, Austria, ³Department for Child and Adolescent Psychiatry, Eating Disorders Unit,, Vienna, Austria

Objectives: Parents play a crucial role in the treatment of anorexia nervosa (AN), as their ability to perceive, understand, and regulate emotions can influence the family climate and the recovery process of affected children. This study explored changes in parental alexithymia and emotion regulation following a parental skills training program, as well as differences between mothers and fathers. Methods: To date, 77 parents (47 mothers, 30 fathers) of patients with AN have been recruited and participated in an eight-week skills training program based on the Maudsley model approach. Participants completed standardized questionnaires assessing alexithymia, emotion regulation, caregiver skills, and expressed emotion at baseline and post-intervention. Results: Preliminary findings indicate higher levels of alexithymia and greater difficulties in specific aspects of emotion regulation among fathers compared to mothers. No significant changes in alexithymia or emotion regulation were observed over the course of the intervention. However, higher baseline alexithymia predicted less improvement in parental skills. Moreover, higher maternal alexithymia was associated with increased parental emotional overinvolvement and criticism toward the patient Conclusions: Future interventions should more specifically address parents’ emotional competencies, as limited access to one’s own emotions and inadequate emotion regulation strategies may negatively affect parents’ ability to support their child’s recovery.

P247

Self-Esteem And Positive And Negative Affect Moderate The Association Between Positive Rumination And Eating Disorder Symptoms
Valerie Wong¹, Ann Haynos², Edward Selby¹
¹Rutgers, The State University of New Jersey, New Brunswick, NJ, United States, ²Virginia Commonwealth University, Richmond, VA, United States

Introduction: Positive rumination about eating disorder (ED) behaviors (i.e., repetitive focus on thoughts such as, “I feel powerful when I suppress my appetite”) is an understudied cognitive mechanism that may reinforce engagement in ED behaviors. Little is known about how and under what conditions positive rumination contributes to the maintenance of these behaviors. Methods: Undergraduate participants (N=431) completed self-report measures of the Positive Rumination In Disordered Eating Questionnaire (PRIDE), ED Examination Questionnaire, State Self Esteem Scale, and Positive and Negative Affect Schedule. Linear regression models tested moderation. Results: PRIDE was a significant positive predictor of ED symptoms across models. Self-esteem and positive affect significantly buffered this association, such that higher self-esteem (β = −.17, p <.001) and higher positive affect (β = −.08, p = .013) weakened the relationship between positive rumination and ED symptoms. Negative affect significantly amplified this association, such that higher levels of negative affect strengthened this relationship (β = .11, p <.001). Conclusions: The relationship between positive rumination and ED symptoms varies by self-evaluative and affective context. High self-esteem and positive affect weaken this relationship, whereas negative affect strengthens it. Positive rumination about ED behaviors may function to bolster self-esteem and positive affect and reduce negative affect.

P248

Prevalence And Characteristics Of Sexual Traumatic Events In Patients With Eating Disorders
Gry Kjaersdam Telléus^1,2, Kristine Kahr Nilsson²
¹Unit for Psychiatric Research, Aalborg University Hospital, Aalborg, Denmark, ²Institute of Communication and Psychology, Psychology, Aalborg University, Aalborg, Denmark

Introduction: Sexual traumatic events (STE) may show a stronger association with ED than other trauma types, potentially influenced by severity and victim–perpetrator relationship. However, gaps remain regarding trauma characteristics and timing relative to ED onset. The aim was to examine prevalence and characteristics of STE in a clinical ED sample and associations with age and perpetrator relationship. Methods: This cohort study included 1,373 patients. The assessment included EDE-16 and a semi-structured trauma interview. Among patients, 263 (19.2%) reported STE. Associations with age at exposure, age at ED assessment, and perpetrator relationship were analysed using chi-square tests. Results: Among those with STE, 32.7% reported negative sexual experiences, 34.2% sexual assault, and 33.1% extreme sexual assault (6.3%, 6.6%, and 6.3% of total ED sample). Most STE cases were single events (83.6%). Extreme STE was more frequent in adults than children/adolescents (45.3% vs. 9.9%, p<0.001), whereas negative sexual experiences were significantly more prevalent among juveniles. The higher prevalence of extreme sexual assault in adults could potentially be attributed to the increased duration of exposure. Conclusions: STE severity was significantly associated with age, with adults reporting more extreme sexual assault and children/adolescents more negative sexual experiences, while no association was found between STE severity and victim–perpetrator relationship.

P249

The Maudsley Model Anorexia Nervosa Treatment For Adolescents And Young Adults (Mantra): Applicability In The View Of Patients
Carina Aichinger¹, Michael Zeiler¹, Petra Sackl-Pammer¹, Susanne Ohmann¹, Sonja Werneck-Rohrer¹, Stefanie Truttmann¹, Julia Klang¹, Konstantin Kopp¹, Helene Krauss¹, Ulrike Schmidt², Andreas Karwautz¹, Gudrun Wagner¹
¹Medical University of Vienna, Vienna, Austria, ²King's College London , London, United Kingdom

Objectives:
This study explores patients’ perspectives on the manualized psychotherapeutic Maudsley Model Anorexia Nervosa Treatment (MANTRa) for adolescents and young adults with anorexia nervosa (AN).

Methods:
Semi-structured qualitative interviews were conducted with 15 patients who received MANTRa. The interview guide included expectations towards the MANTRa treatment prior to its start, positive and helpful aspects as well as negative aspects of the treatment and the workbook including suggestions for improvements, experiences with developing the case formulation and therapist letters. The interviews were transcribed verbatim, and an inductive reflexive thematic analysis approach according to Braun and Clarke was used to explore patterns of meaning. Data coding and analysis was conducted by two independent researchers who were not involved in delivering MANTRa.

Results:
Motivation letters with pro and cons of AN as well as identity formation without AN were identified as particularly beneficial in the treatment course. In contrast, the big volume of the workbook and the lack of less severe case examples included in the workbook were mentioned as negative aspects. Overall, findings provide insights into patients’ perspectives on the applicability, acceptability, therapeutic effects, and underlying mechanisms of MANTRa.

Conclusions:
The findings will inform further refinement of MANTRa to enhance acceptability and optimize therapeutic impact.

P250

 A Randomised Controlled Trial (Rct) Of Juniver Versus Wait-List Control: Support For A Digital Intervention Based On Neuroscience And Cognitive-Behavioural Therapy
Karina L Allen¹, Lu Qi¹, Emilie Faure²
¹King's College London, London, United Kingdom, ²King's College London, London, United Kingdom, ³Juniver, London, United Kingdom

Introduction: Juniver is an app-based program for eating disorders (EDs) based on neuroscience, CBT and ‘just in time’ interventions. It incorporates moderated peer support and AI-led support. We present RCT results comparing Juniver to a wait-list control condition. Methods: The study was registered at ClinicalTrials. Participants were ≥16-years and based in the UK or US. Participants self-identified as having an ED (any diagnosis, BMI ≥15) and completed measures of ED symptoms (EDE-Q), depression (PHQ-9), anxiety (GAD-7), psychosocial impairment (CIA) and stress at baseline and weeks 4, 8, 12, 16, 20 and 24. The primary outcome was changes in Global EDE-Q scores to week 12. Analyses used baseline-adjusted mixed models for repeated measures, with restricted maximum likelihood. Results: 357 participants were randomised to Juniver (n=179) or control (n=178). Most were female (90%) and white (70%). 38% provided outcome data to week 12. Juniver participants showed significantly greater reductions than control participants on the Global EDE-Q (primary outcome) (-0.61 [95% CI, -0.94, -0.29]) by week 12. They also showed significantly greater reductions in binge eating (-2.84), clinical impairment (-6.04), depression (-2.26) and anxiety (-2.03). No significant between-group changes were observed for BMI, purging or stress. There were no serious adverse events. Conclusions: Results support the efficacy of Juniver. We will discuss next steps for evaluation and implementation.

P251

Parents&Rsquo; And Guardians&Rsquo; Experiences Of Follow-Up Of Maladaptive Movement During Pediatric Treatment Of Eating Disorders: A Cross-Sectional Survey From Norway.
Solfrid Bratland-Sanda¹, Anne Kari Heggestad², Kristin Sarmon³, Hedda Ø Lia¹, Linda Madsen¹, Ingeborg Nordbø¹
¹University of South-Eastern Norway, Bo Telemark, Norway, ²University of Oslo, Oslo, Norway, ³Horten municipality, Horten, Norway

Introduction. Parents and guardians are core to the treatment of eating disorders in youth. This study aims to examine how they experience the management and follow-up of maladaptive movement, a core symptom of eating disorders symptoms in youth. Methods. An ongoing, cross-sectional online survey is distributed to parents and guardians of children and adolescents admitted to treatment for eating disorders in the past five years. The survey closes June 30^th 2026, hence final data analysis will be conducted in August/September 2026. Results. Preliminary results show 372 respondents per 19.04.26. Maladaptive movement contributed to eating disorders concerns among 30% of the children and adolescents, of which 75% participated in organized sport prior to onset of the illness. Treatment teams with competencies in physiotherapy and/or exercise were reported in 1-2% of the cases depending on type of health care service. For respondents with experiences from family-based treatment in outpatient settings, 63% reported the task of managing maladaptive movement as demanding. The guidance and support for managing maladaptive movement was reported as satisfactory by 23%, dissatisfactory by 40%, and neither satisfactory nor dissatisfactory by 37% of the respondents. Conclusions. Maladaptive movement was a concern in eating disorders identification in 30% of the reported cases, yet there are limitations with how this symptom was managed, guided and followed up by the health care services.

P252

Designing A Virtual Reality CafÉ To Support People With Eating Disorders
Laura Chapman¹, Lydia Shackshaft^1,2, Angela Attwood^3,4, Lucy Biddle^1,4, Gillian Combe⁵, James Downs⁶, Tamsin Ford⁷, Trinisha Govender⁸, Alys Grant⁹, Annabelle Hook^1,5, Paul Moran^1,2, Ian Penton-Voak^3,4, Emily Rothwell¹⁰, Anne Stewart¹¹, Lucy Yardley^3,12, Helen Bould^1,4,8
¹Bristol Medical School, University of Bristol, Bristol, United Kingdom, ²University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, United Kingdom, ³School of Psychological Science, University of Bristol, Bristol, United Kingdom, ⁴NIHR Biomedical Research Centre, University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, Bristol, United Kingdom, ⁵Oxford Health NHS Foundation Trust, Oxford, United Kingdom, ⁶Expert by Experience, Cardiff, Wales, United Kingdom, ⁷Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom, ⁸Gloucestershire Health and Care NHS Foundation Trust, Gloucestershire, United Kingdom, ⁹Expert by Experience, Canterbury, United Kingdom, ¹⁰Greater Manchester Mental Health Foundation Trust, Manchester, United Kingdom, ¹¹Department of Psychiatry, University of Oxford, Oxford, United Kingdom, ¹²School of Psychology, University of Southampton, Southampton, United Kingdom

Introduction: Many people with eating disorders (ED) find social eating difficult, and being able to eat socially can be important for recovery. Previous research has identified that a virtual reality (VR) café environment could be a useful ED treatment adjunct for practicing social eating. Methods: We used the Person-Based Approach to develop a VR café intervention for people with ED who find social eating challenging. In Study 1 we conducted qualitative work with people with ED (n=15), parents/carers (n=4), and clinicians (n=6), to inform the café’s design. In Study 2, the café was refined via co-design activities and interviews with people with ED (n=12). Results: Study 1 identified a range of café-related challenges (e.g. busyness; interactions with staff; choosing and ordering food/drink) which were incorporated into the initial build of the VR café by our industry partners, Kiin. Study 2 participants contributed to scripts for café staff; food and drink menus; intervention outcome measures; and guidance for clinicians. They also identified areas for improvement to the VR café. Conclusions: Using the Person-Based Approach has enabled us to co-design scenarios within a VR café where people with ED can practice a variety of challenges, supported by a clinician. The intervention aims to reduce anxiety and increase confidence in social eating settings, and is being offered to young people accessing ED treatment in two NHS trusts in the UK, via a mixed methods feasibility trial.

P253

Dissonance-Based Eating Disorder Prevention For Young Women In Portugal: Examining The Body Project&Rsquo;S Efficacy, Delivery Modality, And Preference Match
Carol Coelho, Rita Ramos, Tânia Rodrigues, Sónia Gonçalves, Paulo PP Machado
Psychology Research Centre (CIPsi), School of Psychology, University of Minho, Braga, Portugal

The current study evaluated the efficacy and feasibility of the Body Project in Portugal and explored long-term modality differences in efficacy and whether matching participants to their preferred modality moderates intervention outcomes. A total of 147 female university students with body concerns, aged 18 to 30 years, were randomly assigned to one of the peer-led Body Project interventions –in-person or virtual – or to a waitlist control. Three separate linear mixed-effects models were used for each outcome. Participants in the in-person and virtual Body Project reported high satisfaction with the intervention and showed significant improvements from pre- to posttest across outcomes compared to the waitlist, except for self-esteem in the virtual group. Improvements remained significant at 6- and 12-month follow-ups, except for negative affect and dieting behaviors at 12-month follow-up in the in-person group. While both interventions produced comparable outcomes, the in-person group showed larger immediate gains, whereas the virtual group showed delayed gains. Matching participants to their preferred modality significantly moderated the effect of delivery modality on changes from pre- to posttest in thin-ideal internalization, dieting behaviors, eating disorder symptomatology, and body appreciation. Exploratory analyses suggested that matched participants tended to show larger gains in the in-person intervention, whereas unmatched participants showed larger gains in the virtual intervention.

P255

Digital Cognitive Behavioral Therapy For Children With Avoidant/Restrictive Food Intake Disorder And Their Caregivers: Preliminary Findings Of A Pilot Feasibility Trial
Julia E. Engelkamp¹, Lara-Marie Koeder¹, Jennifer J. Thomas^2,3, Kamryn T. Eddy^2,3,4, Andrea S. Hartmann¹
¹Department of Psychology, Clinical Psychology and Psychotherapy of Childhood and Adolescence, Konstanz University, Konstanz, Germany, ²Eating Disorders Clinical and Research Program, Massachusetts General Hospital, Boston, MA, United States, ³Department of Psychiatry, Harvard Medical School, Boston, MA, United States, ⁴Division of Child and Adolescent Psychiatry, AMC Department of Psychiatry, Massachusetts General Brigham, Boston, MA, United States

Introduction: Cognitive behavioral therapy (CBT-AR) for avoidant/restrictive food intake disorder (ARFID) shows promising findings, yet many individuals face barriers to accessing specialized therapy. Digital interventions may enhance accessibility by providing flexibility in time and location. This pilot study examined the feasibility and acceptability of digital CBT-AR for children with ARFID. Method: In a single-arm pilot study (German Clinical Trials Registry: DRKS00034963), ten German-speaking children aged 8–14 years with ARFID and their caregivers received 12-sessions of digital CBT-AR, combining therapist-guided video sessions and self-guided modules. Recruitment and dropout rates were assessed as feasibility indicators. Participant feedback and self-reported ARFID symptoms were measured pre-, during, post-intervention, and at 4-week follow-up. Results: Participants had a mean age of 10.7 (SD = 2.31) and 50% were female. The recruitment rate was 2.5 patients per month with 20% drop-out. Preliminary descriptive findings indicate good to excellent satisfaction (Client Satisfaction Questionnaire parents: M = 27.12, SD = 2.17) and a modest reduction in symptoms (Nine-Item ARFID Screen: pre M = 32.90, SD = 5.78; post M = 27.50, SD = 4.31; follow-up M = 28.88, SD = 4.42). Conclusion: These preliminary findings suggest that the digital intervention is feasible and well accepted, supporting further investigation in larger-scale efficacy trials.

P256

Body U Teens: Implementation Of An Eating Disorders Screening And Early Intervention Program In Missouri Schools
Marie-Laure Firebaugh¹, Ellen E. Fitzsimmons-Craft¹, Carli P. Howe¹, Laura D'Adamo², Annie Seal³, Marge Cole³, Patricia A. Cavazos-Rehg¹, Denise E. Wilfley¹
¹Washington University in St. Louis, St. Louis, MO, United States, ²Drexel University, Philadelphia, PA, United States, ³Missouri Eating Disorders Council, Jefferson City, MO, United States

Introduction: Adolescence is the peak period of onset for eating disorders (EDs), yet EDs are greatly under-identified and treated. To address this gap and prevent progression to more severe illness, we created Body U Teens to screen, prevent, and treat EDs in middle and high schools. Method: The Stanford-Washington University EDs Screen for youth was implemented in Missouri (MO) schools to match teens (ages 12-17 years) with evidence-based digital programs based on risk level: 1) a guided self-help intervention for clinical/subclinical binge-type EDs; 2) a self-help prevention program for teens at high risk for EDs; 3) and a self-help program to maintain healthy habits for those at low risk. Teens who screened for anorexia nervosa received community treatment resources. Results: Body U Teens was successfully implemented in 3 private schools and 4 school districts. We screened 2,921 students of which 12.8% screened positive for a possible ED, consistent with national prevalence estimates. Among those screened with a possible ED, 70.6% were girls and 29.4% were boys. We trained 481 school professionals including teachers, nurses, and counselors to identify risks associated with EDs. Stakeholder qualitative data will be presented at the meeting. Conclusion: Body U Teens leverages statewide partnerships (e.g., MO EDs Council) and internal champions (e.g., school nurses, counselors) to reduce barriers to care and significantly improve ED identification, prevention, and intervention for teens.

P257

Interventions For Eating Disorders And Disordered Eating In Autism Spectrum Disorder: A Scoping Review
Alice Garrood¹, Alison Bethel¹, Tamsin Newlove-Delgado¹, Sophie Blummers², Vashti Berry¹
¹University of Exeter Medical School , Exeter, United Kingdom, ²Torbay and South Devon National Health Service Foundation Trust, Torbay, United Kingdom

Introduction Autism Spectrum Disorder is associated with disordered eating (DE) and eating disorders (ED), yet evidence-based autism-adapted interventions are lacking. This scoping review maps the intervention landscape and identifies translational gaps. Methods A scoping review was conducted using JBI methodology and PRISMA-ScR guidelines. Eight databases were searched from inception. Studies of any design evaluating interventions for DE/ED in autistic individuals were included. Data on intervention characteristics, adaptations, outcomes, and delivery were extracted and synthesised. Results Twenty-two studies (2009-2025), mainly US/UK, were included. Evidence was narrow, biased toward early childhood, with limited adolescent/adult representation. Interventions were mainly behavioural, with little autism-specific adaptation or sensory/cognitive integration. Parent-mediated approaches were uncommon. Designs were observational or service evaluations, with few controlled trials. ASD and eating-related definitions were inconsistent and often non-diagnostic (e.g., "food selectivity"), limiting comparability. Outcomes were heterogeneous across behavioural, psychological, clinician, and service domains. Conclusions The evidence base is underdeveloped and methodologically limited. Few studies evaluate autism-adapted ED interventions, particularly beyond childhood. Standardised diagnostic and outcome frameworks and co-produced autism-informed interventions are urgently needed.

P258

Specialized Post-Inpatient Psychotherapy For Sustained Recovery In Anorexia Nervosa Via Videoconference &Ndash;An Update On The Sustain Trial
Katrin Giel^1,2, Florian Junne³, Peter Martus⁴, Martin Diers⁵, Tobias Hofmann⁶, Bernd Löwe⁷, Georgios Paslakis⁵, Martin Teufel⁸, Ulrich Voderholzer⁹, Jörn von Wietersheim¹⁰, Beate Wild¹¹, Almut Zeeck¹², Wolfgang Bethge¹³, Ulrike Schmidt¹⁴, Stephan Zipfel^1,2, Kathrin Schag^1,2
¹Medical University Hospital , Tübingen, Germany, ²Center of Excellence in Eating Disorders, Tübingen, Germany, ³University Hospital, Magdeburg, Germany, ⁴Medical Faculty, Tübingen, Germany, ⁵LWL-University Hospital , Bochum, Germany, ⁶Charité - Universitätsmedizin, Berlin, Germany, ⁷University Hospital , Hamburg, Germany, ⁸LVR University-Hospital, Essen, Germany, ⁹Schoen Clinic Roseneck, Prien, Germany, ¹⁰University Medical Center, UIm, Germany, ¹¹University Hospital , Heidelberg, Germany, ¹²University Hospital , Freiburg, Germany, ¹³Center for Clinical Trials, Tübingen, Germany, ¹⁴King’s College , London, United Kingdom

Background: Relapse after inpatient treatment is a major clinical challenge in the treatment of anorexia nervosa (AN). There is an urgent need for specialized care approaches offering effective aftercare and relapse prevention to improve long-term outcomes for patients with AN. Methods: SUSTAIN is a multicenter, prospective, randomized controlled trial investigating the effectiveness of a novel aftercare intervention for patients with AN compared to optimized standard treatment (TAU-O). The SUSTAIN intervention is based on Schmidt & Treasure's cognitive-interpersonal maintenance model of AN. It comprises 20 treatment sessions over eight months and is primarily conducted via videoconference to avoid interruptions in care. TAU-O refers to outpatient psychotherapy as offered in the German healthcare system. The minimum body mass index (BMI) at the start of the study is 15 kg/m². The primary efficacy endpoint is the change in BMI between the start of the study (T0) and end of treatment (T2). Results: The recruitment target of 190 patients was achieved in 2025. The recruitment period showed that the disorder severity in patients with AN receiving inpatient treatment has increased. Data collection is currently ongoing and will be completed in autumn 2026. We will share first experiences with trial conduct and qualitative feedback from patients who completed SUSTAIN treatment. Discussion: The results of the SUSTAIN study will contribute to the further development of aftercare interventions for AN.

P259

Food Noise Decreases During Cognitive Behavioral Therapy For Eating Disorders And Predicts Binge-Eating Outcomes
Haley Graver^1,2, Shahad Salman², Adarsh Javvaji², Adrienne Juarascio³, Stephanie Manasse¹
¹Department of Psychological and Brain Sciences, Drexel University, Philadelphia, PA, United States, ²Center for Healthcare Delivery Science, Nemours Children’s Health, Wilmington, DE, United States, ³Oregon Research Institute, Eugene, OR, United States

Food noise, i.e. persistent preoccupation with food, may interfere with treatment response for binge-spectrum eating disorders (BSEDs) via cravings to binge eat (BE), yet no research has examined this question. We examined if food noise decreases during cognitive behavioral therapy for BE (CBT-E) and if change in food noise is associated with BE outcomes. Methods: N=192 adults with BSEDs received CBT-E, focused version. Food noise was measured using the Eating Disorder Examination Eating Concern subscale item assessing the number of days thoughts about food/eating/calories interfered with concentration. Regression models tested whether change in food noise predicted post-treatment BE frequency, controlling for baseline BE frequency and baseline food noise. Sensitivity analyses tested whether results persisted when controlling for change in the other Eating Concern subscale items. Results: Food noise decreased from baseline to post-treatment (∆=-8.98, 95% CI [-10.52, -7.44], p<.001). Greater improvement in food noise predicted lower post-treatment binge frequency (b=-0.62, 95% CI [-0.77, -0.48], p<.001). Food noise remained predictive when change scores in the other Eating Concern items were included. Conclusions: Food noise decreased substantially during CBT-E and greater reductions in food noise were associated with lower binge frequency at post-treatment. Results suggest that CBT-E may reduce food noise and that food noise may be an important marker of CBT-E response.

P260

Systematic Review Of Implementation Strategies In The Treatment Of Anorexia Nervosa
Hazal Y Gurcan¹, Ha Li Boyce², Brittany Matheson²
¹Dartmouth College, Hanover, NH, United States, ²Stanford University School of Medicine, Stanford, CA, United States

Introduction: Despite the existence of evidence-based treatments (EBTs) for eating disorders, these treatments are not broadly available. Existing implementation science research in eating disorders has focused on identifying barriers and facilitators through interviews with key stakeholders. However, minimal research has examined which implementation strategies have been used to address barriers or facilitators. This systematic review will examine strategies used to address the research-practice gap in the treatment of anorexia nervosa (AN). Methods: This systematic review will be prospectively registered with the PROSPERO database. Two independent reviewers will screen articles through MEDLINE, Cochrane Reviews, Cochrane Trials, PsycINFO, and SCOPUS. Inclusion criteria include: published articles, written in English, evaluating EBTs for AN using experimental or quasi-experimental study designs. Articles on other eating disorders or using non-EBTs will be excluded. Implementation strategies will be identified using the Expert Recommendations for Implementing Change (ERIC), and implementation outcomes will be measured using the Reach, Effectiveness, Adoption, Implementation and Maintenance Framework (RE-AIM). Results: Article identification and analyses are in progress, and will be completed by June 2026. Conclusions: The findings of this review will promote the scaling of AN treatments by identifying implementation strategies that have successfully supported treatment scaling across settings.

P261

Targeting Eating Disorder Symptoms In Severe Obesity Through Smartphone-Supported Behavioral Weight Loss Treatment: An Exploratory Randomized Controlled Trial (Smartbwl)
Anja Hilbert¹, Lisa-Marie Okhof¹, Christiane Prettin², David Petroff², Adrienne Juarascio³, Claudia Huebner¹
¹Department of Psychosomatic Medicine and Psychotherapy, University of Leipzig Medical Center, Leipzig, Germany, ²Clinical Trial Center Leipzig, University of Leipzig, Leipzig, Germany, ³Oregon Research Institute, Eugene, OR, United States

Introduction: Behavioral weight loss treatment (BWL), the standard intervention for severe obesity (SO; BMI ≥40 kg/m² or ≥35 kg/m² with comorbidity), often results in moderate but unsustained weight loss and insufficient improvement in eating disorder symptoms. This exploratory randomized controlled trial (RCT) evaluated a personalized cognitive-behavioral ecological momentary intervention app adjunctive to BWL (SmartBWL) to support daily weight management and eating regulation skills. Methods: In this assessor-blind RCT, 100 adults with SO (74% female) were randomized to standard group-based BWL or SmartBWL delivered over 6 months (DRKS00026018). Assessments at baseline, midtreatment, posttreatment, and 6-month follow-up were analyzed intent-to-treat. Results: At posttreatment, SmartBWL showed a small additional weight loss compared to BWL (0.3 kg; 95% CI −2.4 to 3.0). Feasibility and acceptability were high, reflected by extensive app engagement (98%), implementation of 97% of just-in-time adaptive interventions and higher patient-rated utility, usability, and satisfaction (small to medium effects). Dropout amounted to 20% for each arm. Very small to small improvements favored SmartBWL regarding binge eating, eating disorder psychopathology, craving, depressive symptoms, quality of life, and skill use. Conclusions: Personalized smartphone-supported BWL may enhance outcomes relevant to eating disorder symptoms in SO, suggesting evaluation in a fully powered confirmatory trial.

P262

Additional Benefits Of Neurofeedback In The Treatment Of Patients With Anorexia Nervosa &Ndash; A Novel Treatment Approach
Jana Karry, Anna Winkeler, Daniela Dumat, Sandra Zara, Hartmut Imgart
Competence Center for Eating Disorders, Parkland Clinic, Im Kreuzfeld 6, 34537, Bad Wildungen, Germany, Bad Wildungen, Germany

Introduction. In our previous pilot study, we observed improved symptoms of anorexia nervosa in patients with anorexia nervosa and post-traumatic stress disorder treated with infra-low frequency neurofeedback (NFB). At the neural level, individuals with anorexia nervosa exhibit alterations in both the inter- and intraconnectivity of large neural networks as well as impairments in the functionality of reward and anxiety networks. These networks are often associated with symptoms of anorexia nervosa, such as obsessive thoughts and impaired emotional regulation as well as general hyperarousal of the central nervous system. Electroencephalography-NFB can influence these processes through neural plasticity and the brain’s capacity for self-regulation and -correction. We assume that NFB has a direct positive effect on eating disorder symptoms. Methods. A randomized controlled double-blind study (intervention n=30 and active control n=30) is conducted in a psychosomatic clinic and aims to compare symptoms of anorexia nervosa in pre- to post-treatment and 6-month follow-up. Ethics approval was received by the Medical Association of Hesse. Results. Data collection began in March 2025. We will present preliminary analyses based on n=20 pre- and post-test and n=10 follow-up values. Conclusion. The present study aims to provide initial insights into the role of NFB in the treatment of eating disorders. Our study adds to the evidence of NFB improving symptoms of anorexia nervosa.

P263

An Updated Systematic Review And Meta-Analysis Of A 10-Session Cognitive Behavioural Therapy For Non-Underweight Eating Disorders.
Gabe Krason-Smith, Talar Moukhtarian, Glenn Waller, Caroline Meyer
University of Warwick, Coventry, United Kingdom

This study aims to provide an updated meta-analysis of the effects of cognitive behavioural therapy – ten sessions (CBT-T) on eating disorder outcomes. Since Keegan et al., (2022), the corpus of published papers involving CBT-T has more than doubled, warranting a re-evaluation. The primary outcomes include eating disorder psychopathology, weekly objective bingeing and vomiting frequencies, clinical impairment, depression, and anxiety. Secondary objectives include examining categorical changes in clinical presentation and maintenance of treatment effects beyond the end of treatment. It will also incorporate novel subgroup analyses (e.g., diagnosis, early change) and meta-regressions (e.g., age, comorbidity, and study characteristics). Finally, the review will assess effects of early change as a predictor of overall outcomes, and report on participant dropout rates. The meta-analysis will use a random-effects model and will include assessments of heterogeneity, risk of bias of included studies, and an assessment of publication bias. The project protocol has been registered with the International Prospective Register of Systematic reviews (PROSPERO). 20 papers have been identified for inclusion, with data extraction ongoing. Although final results are pending, the meta-analysis and related manuscript will be completed by July 2026. This review will provide the most comprehensive evaluation of CBT-T to date, and inform clinical practice and future research.

P264

Comparative Efficacy Of Pharmacological Interventions For Anorexia Nervosa In Adolescents And Adults: A Systematic Review And Meta-Analysis
Kristina T Kumpf¹, Emily Behling², Harriet Isherwood³, Tara Ramsay-Patel⁴, Kelsey Hagan¹, Michael Bloch², Rebecca Kamody²
¹Virginia Commonwealth University, Richmond, VA, United States, ²Yale School of Medicine, New Haven, CT, United States, ³Independent Researcher, London, United Kingdom, ⁴University College London, London, United Kingdom

Objective: Anorexia nervosa (AN) is a difficult-to-treat condition with limited evidence-based treatments relative to other eating disorders (EDs). While various medications are used off-label for the treatment of AN, it remains unclear whether these treatments aid in weight restoration and ED symptom reduction. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) of psychiatric medication for the treatment of adolescent and adult AN. Methods: MEDLINE(R) ALL, Embase, PsycINFO, Web of Science, and CENTRAL were searched with the terms “Anorexia Nervosa AND Randomized Control Trial” to identify RCTs. Data were pooled through random-effects meta-analysis. Results: 23 RCTs reporting body weight or BMI outcomes were included, with 9 reporting ED symptoms. Only olanzapine was associated with a significant increase in body weight or BMI relative to placebo (SMD=.33; 95%CI =.09-.58; p=.008). Likewise, no medication demonstrated significant effects on ED symptoms; fluoxetine showed no effect (SMD=-.03; 95%CI=-.50-.44; p=.90) and olanzapine showed non-significant worsening of symptoms (SMD=.26; 95%CI =-.02-.53; p=.07). Conclusions: Despite modest weight improvement, there is limited evidence for use of olanzapine for AN, and few additional candidates among traditional pharmacotherapy. With growing interest in adapting interventional psychiatric modalities for the treatment of AN, further study is needed to establish the efficacy of these emerging treatments.

P265

Open Versus Blind Weighing And Children'S Portioning Autonomy As Predictors Of Weight Gain In Adolescent Anorexia Nervosa: Evidence From An Outpatient Setting
Corina Lendfers¹, Michael Berndonner ^{1, 2}
¹Kompetenzzentrum FiT Anorexie , Chur, Switzerland, ²Martin-Luther-Universität Halle-Wittenberg, Halle, Germany

Introduction: Adolescent anorexia nervosa is associated with high relapse rates. While clinical and psychological predictors of outpatient weight gain have been studied, the role of specific parental behaviors on sustained weight gain in the outpatient setting remains largely unexplored. This study investigates two modifiable predictors: weighing method (open vs. blind) and children's portioning autonomy.
Methods: Data from a standardized, anonymous parent-reported online questionnaire (target n ≥ 200; preliminary n = 135) from Germany, Austria, and Switzerland were analyzed using chi-squared tests.
Results: Preliminary analyses reveal a moderate-to-strong association between blind weighing and higher weight gain rates compared to open weighing (77.8% vs. 35.3%; X² = 9.062, p = .003, V = .414). Children served portions by their parents showed significantly higher weight gain rates than those who portioned independently (X² = 11.20, p = .004, V = .543), indicating a strong effect. A clinically meaningful symptom reduction was consistently observed when weight approached the premorbid BMI percentile.
Conclusions: These preliminary findings suggest that blind weighing and restricted portioning autonomy are associated with better weight outcomes in adolescent anorexia nervosa. The premorbid BMI percentile emerges as a relevant clinical target for symptom remission. Final analyses will be presented at the congress, with direct implications for outpatient treatment protocols.

P266

Acceptability And Feasibility Of A Single-Session Online Parent-Focused Intervention Targeting Body Image Development In Young Children
Anna Love, Sarah Domoff, Julia Hormes
University at Albany, Albany, NY, United States

Objective: Body image concerns are linked longitudinally to disordered eating and can emerge as early as ages 3-9; yet, few parent-focused interventions target these concerns in young children. This study examines the acceptability and feasibility of a single-session parent training intervention targeting early risk factors for eating disorders. Methods: Intervention development was informed by a needs assessment in which parents expressed a need for guidance on conversations about weight, health, and appearance, as well as a preference for an online modular format. The intervention includes four modules: Body Image Development, Food Talk, Mealtime and Picky Eating, and Media Usage. 24 parents were randomized to complete one module and provide qualitative feedback. Then, 100 parents (50 mothers, 50 fathers) completed the entire intervention, along with measures of acceptability and feasibility (ClinicalTrials.gov, NCT07179068). Results: 86 % of parents completed the full intervention and all assessments. Parents rated it as logical (M = 8/10), helpful (M= 7.91/10), and indicated that they would recommend it to a friend (M = 8.21/10). 98 % of parents supported integration of the intervention into pediatric care. Discussion: Findings support the acceptability and the feasibility of the intervention. A future full-scale efficacy trial is required to ensure that the intervention is effective in targeting body image development in young children through parent education.

P267

A Holistic Investigation Of Early Change And Baseline Predictors Of Multiple Treatment Outcomes For People With Anorexia Nervosa (An) And Atypical An.
Haider Mannan¹, Janet Conti¹, Joon Bae¹, Sinead Day², Deborah Mitchison², Phillipa J Hay¹
¹Western Sydney University, Campbelltown, Australia, ²University of Technology Sydney, Ultimo, Australia

Objective: There are few investigations of early response across a bread range of clinically relevant outcomes in ED treatments. This paper sought to assess early change and baseline predictors of holistic treatment outcomes (ED symptoms, body weight and quality of life (QoL)) in ED residential care. Methods: The sample consisted predominantlyof women diagnosed with Anorexia Nervosa (AN) or Atypical AN (n = 85). Multiple linear regression assessed the predictive power of early response and baseline variables for ED symptoms, body weight and QoL. Weighted multiple linear regression was used when heteroscedasticity was detected. Multiple imputation using chained equations was used to account for missing data. Results: Early treatment predictors of higher ED symptoms at discharge in order of importance were improvements in ED symptoms, and in mental and physical health related QoL but higher BMI was not significant. Early improvement in physical health related QoL predicted higher BMI at discharge. Regarding baseline measures, lower ED symptoms and higher mental-health (MH) related QoL predicted better both symptomatic and MHQoL treatment outcomes. Conclusions: Expanding upon and consistent with previous research, this study demonstrates the prognostic significance of early response and baseline characteristics more broadly in eating disorder care. Findings highlight the clinical relevance of early change in QoL as well as ED symptoms for outcomes and treatment targets.

P268

Adolescents With Atypical Anorexia Nervosa In Family-Based Treatment (Fbt)
Brittany Matheson¹, Qianheng Ma¹, Ainsley Cogburn¹, Jennifer Couturier², James Lock¹
¹Stanford University School of Medicine, Stanford, CA, United States, ²McMaster University, Hamilton, ON, Canada

Introduction: Previous randomized clinical trials of family-based treatment (FBT) for adolescents with anorexia nervosa (AN) excluded participants above the 88^th%tile for expected body weight (%EBW). Thus, the weight trajectories and clinical outcomes of adolescents with atypical AN (AAN) have yet to be explored. Methods: Participants were adolescents 12-18 years old with AAN (defined as at or above 88% EBW at baseline) enrolled in a randomized clinical trial comparing FBT to guided self-help FBT. Weight and height were collected at baseline to calculate %EBW. Weight was collected weekly throughout treatment and at end-of-treatment. Results: As a group, adolescents with AAN (n=74; 14.24±1.43 y; 88.19% female; 59.53% White/Non-Hispanic) gained on average 1.96 kg (SD: 2.74) by session 4. By EOT, adolescents with AAN gained an average of 3.91 kg (SD: 4.45). Compared to adolescents with AN (n=53), adolescents with AAN (n=74) were less likely to drop out of treatment (7.09% vs 16.54%, x²test p<.01). Conclusions: These preliminary data suggest that FBT regardless of format is effective at promoting weight gain for adolescents with AAN, who may be less likely to discontinue treatment than adolescents with AN. Future studies should explore what differences, if any, exist in cognitive and behavioral outcomes for adolescents with AAN compared to AN and should consider inclusion of adolescents with AN across the weight-spectrum to enhance generalizability of clinical findings.

P269

Template-Guided Multimodal Inpatient Therapy For Anorexia Nervosa. A Naturalistic Study.
Yoan Mihov^1,2, Lisa Guth¹, Tugce Aras¹, Lisa-Katrin Kaufmann^1,3, Stephen A. Wonderlich^4,5, Gabriella Milos¹
¹University Hospital Zurich, Department of Consultation-Liaison Psychiatry and Psychosomatic Medicine, Zurich, Switzerland, ²Department of Psychology, Clinical Psychology and Psychotherapy, Freiburg, Switzerland, ³University of Zurich, Department of Psychology, Zurich, Switzerland, ⁴Sanford Center for Biobehavioral Research, Fargo, ND, United States, ⁵University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, United States

1. Introduction Anorexia nervosa (AN) is a severe eating disorder with low recovery, high relapse rates, and high mortality. There is an urgent need for improvement of available treatment, especially in inpatient settings where persons with the most severe AN are treated. 2. Methods Inpatient program-templates were developed as tools to structure and coordinate a consistent, yet flexible interdisciplinary inpatient treatment for AN. Their feasibility was tested at a specialized eating disorder unit of the Psychiatric University Hospital Zürich: clinical outcomes of template-guided treatment were longitudinally assessed in a single-arm naturalistic study, comprising admission, discharge, and follow-up. 3. Results Analysis was carried out in 92 individuals (87 female) with AN who provided data at both admission and discharge. Data attrition did not allow for adequate testing of follow-up outcome. There was a significant increase in BMI and a significant decrease in self-reported eating disorder psychopathology, depressive, obsessive-compulsive, anxiety, and alexithymia symptoms. Participants with lower BMI at admission and longer inpatient treatment duration gained more weight. 4. Conclusions The present study supports the efficacy and feasibility of a template-based treatment procedure for AN. The major limitations are the single-arm design and limited sample size. Template-based programs provide clarity and guidance, allowing a consistent yet individually tailored treatment.

P270

A Feasibility Study Of A Digital Self-Led Nature Connectedness Intervention For People Experiencing Disordered Eating
Mia L Morgan^{1, 2}, Brenda Caldwell Phillips¹, Charlotte Scott¹, Miles Richardson¹
¹University of Derby, Derby, United Kingdom, ²University of Bath, Bath, United Kingdom

Introduction
Providing novel, accessible and scalable interventions for disordered eating (DE) is essential given treatment barriers and modest recovery rates. Nature connectedness (NC) supports those experiencing DE by improving factors such as body appreciation, emotion regulation and identity. This study assessed the feasibility of Appreciating Nature, the first NC intervention for this population. The 4‑week, self-led digital intervention was co-designed with target users and DE clinicians. Methods
A mixed-methods, single-arm feasibility study was conducted with people with DE (N = 46). Acceptability (e.g., enjoyment, satisfaction, perceived benefits) was assessed with Likert-scale and open-ended survey items, post-intervention and at 4‑week follow-up. Preliminary efficacy across outcomes (N = 5; e.g., body image, life meaning), recruitment, retention and acceptability of the study design were also evaluated. Results
Intervention completers (n = 13) reported high acceptability. Benefits centred around subjective improvements in body image, emotion regulation and NC. Most outcomes showed small, predicted improvements. Recruitment was successful, but retention was low (24% completed all measures). Some dropouts faced practical difficulties with the study platform. Conclusions
Appreciating Nature shows promise as a novel intervention for people with DE. Refinements to enhance engagement and efficacy, including professional check-ins, are recommended before pilot testing.

P271

Adolescents&Rsquo; And Parents&Rsquo; Experiences Of Family-Based Treatment For Anorexia Nervosa In A Scandinavian Context
Signe Holm Pedersen¹, Mette Bentz¹, Stine Bay², Julie Midtgaard^3,4
¹Child and Adolescent Mental Health Center, Copenhagen University Hospital – Bispebjerg and Frederiksberg, Copenhagen, Denmark, Copenhagen, Denmark, ²Danish National Association for Eating Disorders and Self-Harm, Valby, Denmark, Copenhagen, Denmark, ³Mental Health Center Glostrup, CARMEN (Centre for Applied Research in Mental Health Care), Copenhagen University Hospital – Amager and Hvidovre Hospital, Hvidovre, Denmark, Copenhagen, Denmark, ⁴Dept of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark, Copenhagen, Denmark

Introduction: Family-Based Treatment (FBT) for Anorexia Nervosa (AN) in Young People (YP), mobilises parents to restore weight and normalise eating but has been criticised for being emotionally demanding and challenging family relationships, particularly in autonomy-oriented cultures such as in Scandinavia. Methods: Semi-structured interviews with 15 YP and 20 parents explored experiences of FBT in Denmark, analysed with thematic and narrative approaches. Results: YPs described a progression from distress over parental control to increased freedom from AN, alongside challenges with trust and a shift from conflict to improved communication and closeness. Parents’ experiences followed three trajectories: strong alignment with FBT and strengthened relationships (Straight Road), negotiated collaboration with relational gains (Bumpy Road), or misalignment with unmet support and ongoing strain (Detoured Road). Conclusions: Findings emphasise that alignment with FBT principles shapes parental experience, while YP benefit from trust, safe clinical spaces, and active parental involvement. Despite initial distress, both groups reported long-term gains in autonomy, communication, and family closeness. Results underscore the importance of culturally sensitive adaptations and targeted support for older adolescents to optimise outcomes, highlighting how treatment experience interacts with parenting norms and family dynamics.

P272

Development And Proof-Of-Concept Testing Of A Single-Session Personalized Feedback Intervention Based On Ecological Momentary Assessment Data For People With Eating Disorders
Sarah E. Racine¹, Elizabeth Hales¹, Laura Lapadat¹, Devyn R. Riddle¹, Samantha Wilson², Maureen Plante³
¹McGill University, Montreal, QC, Canada, ²University of Saskatchewan, Saskatoon, SK, Canada, ³University of Alberta, Edmonton, AB, Canada

Despite significant public health burden, treatment for eating disorders (EDs) is unavailable or does not reach most people who need it. Single-session interventions (SSIs) can be widely disseminated, and personalizing an SSI will better ensure its relevance. In collaboration with a Research Advisory Board consisting of eight people with lived ED experience, we developed a personalized feedback SSI based on ecological momentary assessment (EMA). After two weeks of EMA, participants complete a 1-hour feedback session about their symptoms and connections between symptoms, emotions, and daily activities visualized via an interactive website. They are also given self-management infographics based on their data. A proof-of-concept study included post-intervention quantitative and qualitative assessment. We enrolled 12 participants (5 cisgender women), with two dropping out (one during EMA and one before post-intervention assessment). Survey completion rates (M[SD] = 71.5%[24.5]) and feedback session attendance (92%) support feasibility. Acceptability of the assessment (M[SD] = 6.6/10[2.2]) and intervention (M[SD] = 7.1/10[2.3]) were rated highly by most participants. Qualitative feedback was generally positive, although those with longstanding EDs stated they were already familiar with their symptom patterns and the self-management strategies. We will now complete a randomized waitlist-controlled pilot and feasibility trial with 50 participants.

P273

Key Components Of Effective Nutrition Counseling In Eating Disorder Treatment: A Qualitative Study
Meg Salvia¹, Jaimie Winkler^2,3, Jodi Galin⁴, Lisa Pearl^5,6
¹Boston University, Boston, MA, United States, ²McLean Hospital, Belmont, MA, United States, ³Navigate Nutrition, Arlington, MA, United States, ⁴Private practice, Lexington, MA, United States, ⁵CNC 360, Lexington, MA, United States, ⁶Simmons University, Boston, MA, United States

Registered Dietitian Nutritionists (RDNs) are consistently recognized as key members of multidisciplinary eating disorder (ED) treatment teams, but research on the impact of nutrition counseling as a component of nutrition rehabilitation and longer-term recovery is sparse. This qualitative study aimed to understand patients’ perceptions of and experiences with nutrition counseling provided by RDNs during ED treatment. We conducted semi-structured interviews with 21 individuals who self-identified as recovered or in recovery from an ED about their experiences in treatment settings with RDNs. Data were analyzed using reflexive thematic analysis. Two central themes emerged: (1) characteristics of the patient-RDN therapeutic relationship and (2) nutrition counseling approaches perceived as supportive to recovery. Participants described RDNs as integral during acute renourishment through implementation and monitoring of nutrition prescriptions and instrumental in longer-term nutrition counseling to resolve anxieties and maladaptive behaviors around food and body image. This research highlights strategies and approaches above and beyond meal plans and monitoring that RDNs can employ in ED treatment. By centering participants' lived experiences, these data clarify how nutrition counseling can be optimized in real-world settings to elevate care, enhance treatment effectiveness, and support sustained recovery.

P274

Co-Designing A Framework To Implement Eating Disorder Care Transition Guidelines For Youth And Young Adults
Sela Scott¹, Maria Nicula², Jayden Lee³, Taqwa Hossain¹, Cheryl Webb², Muhammad Farooq², Tovah Yanover², Ethan Nella², Manya Singh³, Jennifer Couturier^2,4, Gina Dimitropoulos^1,3
¹Faculty of Social Work, University of Calgary, Calgary, AB, Canada, ²Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada, ³Department of Psychiatry, Mathison Centre for Mental Health Research and Education, University of Calgary, Calgary, AB, Canada, ⁴Offord Centre for Child Studies, McMaster University, Hamilton, ON, Canada

Introduction: New guidelines recommending best practices for transitioning youth and young adults (YYAs) from pediatric to adult eating disorder (ED) care have been published, but no framework for implementing these recommendations exists. This study aimed to co-design this framework with various interest holders (IHs). Methods: Two virtual workshops were held with IHs, including YYAs, caregivers, ED specialists, and community organizations. The objective of Workshop 1 was to identify factors impacting ED care transitions. Following the development of a prototype framework by the research team, Workshop 2 aimed to refine this framework with IHs. Workshops were audio-recorded, transcribed verbatim, and analyzed with the Framework Method. Results: 51 IHs participated. Workshop 1 highlighted lack of understanding and fear of adult programs, communication between programs, and more, as aspects impacting transitions. These key outcomes informed a prototype framework that included a resource hub, peer support, planning workbooks, and other tools. Overall, IHs valued the use of these elements in the prototype but raised various concerns about the feasibility of implementing various pieces depending on the context. Conclusion: This work advances understanding of this population by developing and receiving feedback on a framework that can provide developmentally appropriate and collaborative care during the transition. Implementation of the prototype at two Canadian sites is underway.

P275

Naturalistic Evaluation Of The Project Body Neutrality Single-Session Intervention
Arielle C. Smith¹, Robert R. Morris², Kallie O’Harra², Mallory L. Dobias¹, Shivani Dutt³, Jessica Scheer³, Andrea K. Graham¹, Jessica L. Schleider¹
¹Department of Medical Social Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, ²Koko, San Francisco, CA, United States, ³National Eating Disorders Association, White Plains, NY, United States

Introduction: Digital single-session interventions (SSIs) can address body image and eating concerns at-scale. Project Body Neutrality (PBN) is an SSI that was effective in an RCT and is now widely available. Methods: In partnership with social media platforms, a mental health nonprofit Koko identifies at-risk individuals and routes them to PBN. The National Eating Disorders Association (NEDA) hosts PBN on their website. PBN is available to anyone ≥13 years old. Users self-report demographics, clinical characteristics, and proximal outcomes. Results: Over 4 months, 1,074 users accessed PBN (886 via Koko, 188 via NEDA), of which 52.14% completed PBN and 34.45% finished the questionnaires. Of the questionnaire completers, 51.89% selected a gender identity other than cisgender woman/girl, 61.08% identified with a non-white racial/ethnic background, and 62.43% identified as non-heterosexual. In this sample, 73.24% endorsed often or always experiencing weight/shape concerns in the last 3 months, and about half endorsed binge eating, engaging in compensatory behaviors, and/or restricting in the past month. Users reported significant within-person pre-post improvement in hopefulness (d_z=0.52, 95% CI=0.41, 0.63), functionality appreciation (d_z=0.68, 95% CI=0.57, 0.80), and body appreciation (d_z=1.08, 95% CI=0.95, 1.21). Conclusions: PBN appears to reach and benefit diverse individuals engaging in real-world help-seeking. Future research will seek to increase uptake and completion.

P276

A Randomized Effectiveness Trial Of A Dissonance-Based Dual Obesity And Eating Disorder Prevention Program
Eric Stice¹, Paul Rhode², Jeff Gau², Heather Shaw¹, Jasmine Lopez¹
¹Stanford University, Stanford, CA, United States, ²Oregon Research Institute, Springfield, OR, United States

Aims: Evaluate the effectiveness of Project Health, a dual obesity and eating disorder prevention program, relative to a video control condition and conduct an exploratory test of whether adding evaluative conditioning to the response/attention training component enhances intervention effects. Materials and Methods: 138 young adults (M age = 19.4; 76% female; 58% White) were randomized to Project Health groups or a video control condition. Results: Participants randomized to Project Health showed greater decreases in body fat at posttest (d = -0.23) and 6-month follow-up (d = -0.53) than controls. Intervention effects on change in eating disorder symptoms were nonsignificant at posttest (d = -0.14) but significant at 6-month follow-up (d = -0.33). Adding evaluative conditioning to the food response/attention training significantly enhanced the body fat loss effects at posttest (d = -0.36), but not at 6-month follow-up (d = -0.13); there were significant eating disorder symptom reduction effects at posttest (d = -0.37), but not at 6-month follow-up (d = 0.18). Conclusions: Project Health produced greater body fat loss/weight gain prevention effects than controls. However, it only produced marginally greater reductions in eating disorder symptoms, in contrast to past trials. Evaluative conditioning enhanced the body fat loss effects of the food response/attention training element of Project Health.

P277

Protocol For A Non-Inferiority Trial Comparing An Online Guided Intervention For Binge Eating Disorder Associated With Morbid Obesity Vs. Treatment As Usual
Sanne van Luenen, Tessa Meijers, Petra Poelstra, Mignon van Bruggen, Margo de Jonge
Novarum Centre for Eating Disorders and Obesity, Amstelveen, Netherlands

Introduction: Obesity is an enormous public health problem at the moment and it can be related to binge eating and binge eating disorder (BED). Treatments for BED based on CBT-E were found to be effective but have important disadvantages, such as travel time and travel costs to treatment facilities. Guided online interventions may improve accessibility while maintaining effectiveness. The objective of this study is to evaluate the effectiveness of an online intervention for people with BED and morbid obesity. Methods: The study is a non‑inferiority trial in which the guided online intervention is compared with standard face-to-face treatment. The aim is to include 222 participants with BED and morbid obesity in the study. Assessments will be administered at baseline, mid-treatment, post-treatment, and 20- and 40-week follow-up. Outcomes include, among others, binge eating episodes, eating disorder symptoms, clinical impairment, and client satisfaction. The online intervention is based on CBT‑E and incorporates other elements such as psychomotor therapy. Weekly guidance will be provided by psychologists via video calling. Data collection will start in 2027. Conclusions: This new online intervention may improve the care for people with morbid obesity and BED by making it more accessible.

P278

Qualitative Evaluation Of A Novel Serious Game Intervention For Parents Of Adolescents With Anorexia Nervosa
Dorthe Waage¹, Mette Bentz², Signe Holm Pedersen², Anne Bryde¹, Elisa Rafn², Nadia Micali^1,3
¹Center for Eating and feeding Disorders Research (CEDaR), Copenhagen University Hospital – Mental Health Services CPH, Copenhagen, Denmark, ²Child and Adolescent Mental Health Center, Copenhagen University Hospital – Mental Health Services CPH, Copenhagen, Denmark, ³Great Ormond Street Institute of Child Health, University College London, London, United Kingdom

Introduction:
Support for parents of adolescents with anorexia nervosa remains limited. This study evaluates parents’ experiences with a novel serious game intervention designed to enhance carer skills during family treatment, exploring experiences of use as well as perceived barriers and facilitators to engagement.

Methods:
Semi-structured parent interviews (15 pre- and 15 post-intervention, providing longitudinal insights), are conducted and analyzed within a reflective thematic framework.

Results:
Preliminary findings suggest variability in perceived usefulness, influenced by treatment needs, usability, and relevance to individual family contexts. Prior to the intervention, caregivers’ wishes include: (a) providing concrete advice, (b) helping translate and clarify the adolescents’ emotional experiences, and (c) being accessible and easy to use. However, Reported concerns included limited reflection of family complexity and potential challenges in navigating the intervention. While parents were generally positive toward digital support, they emphasized the importance of clear information about serious games due to their novelty. Data collection and analysis are ongoing and will be finalized by October 2026.

Conclusion:
Parents view serious games as a promising digital support; however, they emphasized that interventions must be easy to use while capturing the complexity of family experiences to ensure engagement, particularly given limited time and existing burden.

P279

Spanish Language Pilot Of Multifamily Guided Self-Help Family Based Treatment Groups For Anorexia Nervosa (Mf-Gsh-Fbt)
Aileen Whyte, Brittany Matheson, Ainsley Cogburn, Josephine Sanchez, Natalie Saba, James Lock
Stanford University School of Medicine, Palo Alto, CA, United States

1. Introduction Family-Based Treatment (FBT) is the gold standard treatment for adolescent anorexia nervosa (AN). Our team developed a guided self-help version of FBT and piloted a multifamily group format (MF-GSH-FBT) to enhance scalability and peer support. We extended this model to Spanish-speaking families to address gaps in treatment access and linguistic equity. 2. Methods Intervention materials, including the GSH-FBT educational videos and the FBT parent book, were translated into Spanish. We are conducting semi-structured interviews to assess the acceptability of the group format and gather feedback about the GSH materials. 3. Results 34 families participated in the Spanish-MF-GSH-FBT. Emerging themes suggest that the multifamily format fosters a sense of community that mitigates isolation. Early feedback indicates that Spanish-language GSH educational videos help address barriers to specialized care. We will use thematic analysis to identify and present key themes from participant responses. 4. Conclusions Piloting MF-GSH-FBT for Spanish-speaking families is essential for diversifying evidence-based eating disorder treatments. Findings will inform the implementation of scalable, culturally sensitive interventions for diverse communities.

P280

Trajectories Of Blood Parameters And Body Weight During Inpatient Treatment Of Anorexia Nervosa With Extreme Underweight
Eva P. Wuttke^1,2,3, Adrian Meule^3,4, Ulrich Cuntz^2,5, Ulrich Voderholzer^1,2,6
¹Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Munich, Germany, ²Schoen Clinic Roseneck, Prien am Chiemsee, Germany, ³Department of Psychology, University of Regensburg, Regensburg, Germany, ⁴Department of Medicine, HMU Health and Medical University, Düsseldorf, Germany, ⁵PMU, Paracelsus Medical University Salzburg, Salzburg, Germany, ⁶Department of Psychiatry and Psychotherapy, University Hospital of Freiburg, Freiburg, Germany

Introduction: Laboratory parameters and body weight are key markers of physical stability in patients with severe and extreme anorexia nervosa. However, systematic analyses of trajectories during inpatient treatment with high-calorie refeeding remain limited in extremely underweight patients. Methods: Retrospective data from 519 female inpatients with anorexia nervosa (mean body mass index at admission: 12.6 ± 1.35) treated in a specialized unit (admission body mass index <15 kg/m²) were analyzed over six weeks. Laboratory parameters and body weight were assessed weekly. Results: More than one third of patients showed leukopenia or hypertransaminasemia at admission. Most laboratory parameters and body mass index improved during the six-week treatment period. Lower body mass index and longer illness duration were associated with more rapid changes in body mass index and several laboratory parameters (e.g., hemoglobin and aspartate aminotransferase). Conclusions: These findings underscore the importance of close laboratory monitoring during refeeding in extremely underweight patients with anorexia nervosa. The observed stabilization of laboratory parameters highlights the effectiveness and safety of inpatient refeeding protocols in patients with low baseline body mass index.

9:30

Associations Between Glp-1Ra Use And Lifetime Eating Disorders
Liv Hog¹, Lisa Dinkler¹, Lu Yi¹, Cynthia M. Bulik^{1, 2, 3}, Andreas Birgegård¹, Emma Forsén Mantilla^{1, 4}
¹Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden, ²Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ³Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ⁴Gymnastik- och idrottshögskola, Stockholm, Sweden

Introduction: GLP-1 receptor agonists (GLP-1RAs) have transformed type-2 diabetes and obesity treatment, but concerns exist regarding their use in individuals with eating disorders (EDs). While potentially beneficial in binge eating, they may be harmful in restrictive EDs. This study examined self-reported GLP-1RA use in individuals with lifetime EDs. Methods: Using 5015 cases and 1262 controls from the Eating Disorders Genetics Initiative-2 (EDGI2), we applied multiple logistic regressions to explore the association of lifetime ED diagnosis and GLP-1RA use (prescribed, unprescribed, unsuccessful attempts to obtain the medication) for weight loss or binge eating, in the full sample and by highest lifetime BMI (hltBMI >/≤ 30 kg/m²). Results: In the full sample and the hltBMI>30 kg/m² group, prescribed use was elevated across most EDs (ORs: 1.40–2.62), while anorexia nervosa (AN) showed the opposite pattern (ORs: 0.39–0.71). Unprescribed use was elevated in atypical AN (AAN) and binge-eating disorder (BED) (ORs: 1.47–2.19) in the full sample, and in those with AN and AAN in the hltBMI<30 kg/m² group (ORs: 3.54–6.31). Unsuccessful attempts to obtain the medication were more common in EDs in the full sample and in both BMI groups (ORs: 1.28–2.15). Conclusions: GLP-1RA use and attempts to obtain them were broadly elevated in individuals with lifetime EDs compared to controls. Notably, those with AN and AAN more often used GLP‑1RAs without prescription and outside clinical indication.

10:00

Prevalence Of Eating Disorders And Body Image Dissatisfaction In Africa: A Systematic Review And Meta-Analysis Of Risk And Symptom Levels
Musa Jemal Nagesh, Shemsu Kedir, Isabel Krug
The University of Melbourne, Melbourne, Australia

Eating disorders (EDs), their risk, and body image dissatisfaction (BID) have long been framed as problems of Western, high-income countries. However, growing evidence points to their presence across diverse populations, including Africa. This systematic review and meta-analysis synthesised studies on EDs, ED risk, and BID in Africa; estimated pooled prevalence; examined moderators (e.g., region, age, sex, assessment tools); and assessed study quality. Five databases (MEDLINE, Scopus, Web of Science, ProQuest, PsycINFO) were searched to January 2026. Seventy-five studies (96 data points: 22 EDs, 57 ED risk, 17 BID) were included. Random-effects meta-analyses, subgroup, and meta-regression analyses were conducted. Point prevalence of EDs was 1.1% (95% CI: 0.5–2.4), with binge eating disorder most prevalent (2.1%) and anorexia nervosa least (0.4%). ED risk was 16.0% (95% CI: 12.1–20.8) and BID 59.3% (95% CI: 52.1–66.1). Substantial heterogeneity was observed. Meta-regression indicated regional variation, with higher rates in Northern Africa and lower rates in Eastern and Western regions. Estimates also varied by assessment tool. Three-quarters of studies were rated high quality. These findings highlight a substantial and under-recognised burden of EDs, ED risk, and BID in Africa, underscoring the need for contextually appropriate prevention and intervention strategies.

10:30

Neural Mechanisms Of Exposure Therapy For Avoidant/Restrictive Food Intake Disorder: A Randomized Controlled Trial
Jennifer J Thomas^1,2, Kendra R Becker^1,2, Mark Vangel^1,2, Stefania L Yee,1,2 Jonathan Xiang^1,2, Kelly Armstrong,1,2 Arjun Shreekumar^1,2, P Evelyna Kambanis^1,2, Kathryn G Pasquariello^1,2, Ashley Dunford^1,2, Tara M Holmes^1,2, Brittani Martino^1,2, Elisa Asanza^1,2, Lauren Breithaupt^1,2, Meghan Slattery,1,2 Kathryn S Brigham^1,2, Laura M Holsen^1,2,3, Elizabeth A Lawson^1,2,3, Kamryn T Eddy^1,2,3
¹Massachusetts General Hospital , Boston, MA, United States, ²Harvard Medical School, Boston, MA, United States, ³Denotes shared senior authorship, Boston, MA, United States

INTRODUCTION: Exposure therapy may work by reducing activation in the brain’s salience network (comprising the anterior cingulate cortex, orbitofrontal cortex, and amygdala) to disorder-relevant cues. We conducted a randomized controlled trial (RCT) comparing cognitive-behavioral therapy (CBT-AR, which uses food exposure as the primary intervention) to nutrition counseling (NC, a plausible but non-exposure-based treatment) for avoidant/restrictive food intake disorder (ARFID). METHOD: We randomized 50 non-underweight youth with ARFID (72% male; M [SD] age = 14.3 [2.4] years) to either CBT-AR (n=25) or NC (n=25). At pre- and post-treatment, they completed an fMRI scan with a visual food cue task, with 84% providing usable data across both timepoints. RESULTS: Patients randomized to CBT-AR (vs. NC) showed significantly greater decreases in activation to food cues in both the anterior cingulate cortex (p=.02, between-groups d= 1.09) and orbitofrontal cortex (p=.02, between-groups d=1.01) from pre- to post-treatment, both with large effect sizes. Pre- to post-treatment changes in the amygdala were qualitatively greater in CBT-AR vs. NC, but between-group differences were non-significant. CONCLUSIONS: CBT-AR (but not NC) may work in part by reducing neural activation to food cues in the salience network. A larger RCT exploring whether early reductions in salience network activation to food cues mediate later reductions in ARFID symptoms in CBT-AR vs. NC is currently underway.

10:15

Randomized Controlled Trial Of Cognitive-Behavioral Therapy Vs. Nutrition Counseling For Youth With Avoidant/Restrictive Food Intake Disorder
Kamryn T Eddy^1,2, Laura M Holsen^1,2, Mark Vangel^1,2, Stefania L Yee,1,2 Jonathan Xiang^1,2, Kelly Armstrong,1,2 Arjun Shreekumar^1,2, Kendra R Becker^1.2, P Evelyna Kambanis^1,2, Kathryn G Pasquariello^1,2, Ashley Dunford^1,2, Tara M Holmes^1,2, Brittani Martino^1,2, Elisa Asanza^1,2, Lauren Breithaupt^1,2, Meghan Slattery,1,2 Kathryn S Brigham^1,2, Elizabeth A Lawson^1,2, Jennifer J Thomas^1,2
¹Massachusetts General Hospital, Boston, MA, United States, ²Harvard Medical School, Boston, MA, United States, ³Denotes shared senior authorship, Boston, MA, United States

INTRODUCTION: Cognitive-behavioral therapy for avoidant/restrictive food intake disorder (ARFID) has shown preliminary promise in several open trials but has yet to be evaluated in a randomized controlled trial (RCT). We therefore conducted the first RCT of CBT-AR, comparing it to nutrition counseling (NC), a plausible comparison treatment widely available in the community. METHOD: We randomized 50 non-underweight youth with ARFID (72% male; M [SD] age = 14.3 [2.4] years) to either CBT-AR (n=25) or NC (n=25). At both pre- and post-treatment, patients completed the Food Neophobia Scale (the putative mechanism of CBT-AR); General Nutritional Knowledge Questionnaire (the putative mechanism of NC); and Pica, ARFID, and Rumination Disorder Interview severity scale (the clinical outcome). RESULTS: As predicted, patients randomized to CBT-AR (vs. NC) showed significantly greater decreases in food neophobia (p<.05); patients randomized to NC (vs. CBT-AR) increased more in nutritional knowledge but this between-group difference was non-significant. The CBT-AR group showed significantly greater decreases in ARFID severity (p=.02). CONCLUSIONS: Although both treatments led to improvements in their hypothesized mechanisms, CBT-AR led to significantly greater symptom reduction. This first RCT bolsters the evidence base for CBT-AR and highlights the possible mechanistic value of food neophobia. A larger RCT to evaluate mediators of symptom change in both treatments is currently underway.

9:00

Digital Transdiagnostic Early Intervention For Youth With Disordered Eating: A Randomised Controlled Trial Of 9 Single Session Interventions
Tracey Wade, Mia Pellizzer, Marcela Radunz, Jamie-Lee Pennesi, Yuan Zhou
Flinders University, Adelaide, Australia

Evidence for use of Single Session Interventions (SSIs) to improve disordered eating for young people is promising but sparse. This study used participatory action research to develop nine transdiagnostic SSIs in the NourishED Mind app, which were then evaluated. We will randomise 640 participants, aged 14 to 25, at risk of an eating disorder (≥ 47 on the Weight Concern Scale), to one of 9 unguided SSIs or a control (DOI: 10.1016/j.bodyim.2025.101945). Trait measures of disordered eating, depression, anxiety, self-injury and SSI-specific constructs were collected at pre-intervention and 1-month post-randomisation. State measures were collected at 3 times points, including 1-week post-randomisation. Over the first 14 weeks of data collection 414 participants completed baseline; 325 (79%) accessed their app, higher than engagement in similar digital interventions (59%). Completion of the first half of the SSI (“Learn”) ranged from 15-64%, with behavioural activation being the most engaging topic, followed by social media (49%) and life transitions (42%). Post-intervention assessment completion (67%) is commensurate with digital interventions for disordered eating. Follow-up retention (61%) is commensurate with other youth mental health SSIs. Data collection ceases at the end of April, and full results will be reported. This trial has potential to significantly expand our knowledge of the efficacy of transdiagnostic SSIs in early intervention.

9:45

Nutritional State-Dependent Changes In Subcortical Limbic Structures In Anorexia Nervosa Are Linked To Leptin, Ghrelin, And Neurofilament Light
Marie-Louis Wronski¹, Klaas Bahnsen¹, Fabio Bernardoni¹, Maria Seidel¹, Arne Doose¹, Johanna L. Keeler², Veit Roessner³, Joseph A. King¹, Stefan Ehrlich¹
¹Translational Developmental Neuroscience Section, Division of Psychological and Social Medicine and Developmental Neurosciences, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany, ²Klinik für Psychiatrie, Psychosomatik und Psychotherapie, LVR-Universitätsklinik Essen, Essen, Germany, ³Department of Child and Adolescent Psychiatry, Faculty of Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany

Anorexia nervosa (AN) involves limbic dysfunction, but its neurobiology remains unclear. We examined subcortical limbic morphology across AN nutritional states and tested links to leptin, ghrelin, neurofilament light (NFL), and brain-derived neurotrophic factor (BDNF). We hypothesized reduced volumes in acute AN, partial normalization after short-term weight restoration, and full normalization after long-term recovery. We studied 547 females aged 12-30 years: 168 acute AN, 113 reassessed after ~3 months of weight restoration (>14% BMI increase), 80 weight-recovered individuals, and 299 controls. Ten limbic structures were segmented using FreeSurfer; biomarkers were measured in blood. Group differences, marker associations, and mediation effects were tested with mixed-effects and regression models. Most limbic volumes were reduced in AN (mean=-5.3%; d=0.24-0.76) but normalized after short-term weight restoration (mean change=+5.8%; d=0.30-0.56), except hypothalamic reductions. Rising leptin mediated weight gain-related increases in the left inferior tubular hypothalamus and the left and right nucleus accumbens. Declining ghrelin mediated right nucleus accumbens increase. Decreasing NFL predicted increases in two hypothalamic subunits, the fornix, and the right nucleus accumbens (d=0.56-0.98). Subcortical limbic alterations in AN show marked neuroplasticity. Neuroendocrine recovery may reverse structural changes, and declines in NFL may signal restoration in homeostatic and reward-related regions.

9:15

Foodseq As A Novel Stool-Based Dietary Biomarker In Anorexia Nervosa: A Multivariate Analysis Of Dietary Patterns And Clinical Recovery
Kylie R. Jeffrey^1,2, Nolan W. Ives¹, Sharon Jiang¹, Cynthia M. Bulik^1,3, Ian M. Carroll², Lawrence A. David¹
¹Duke University, Durham, NC, United States, ²University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ³Karolinska Institutet, Stockholm, Sweden

Dietary self-report is unreliable in anorexia nervosa (AN), constraining efforts to link diet to clinical course. FoodSeq, a stool-based DNA metabarcoding approach, offers an objective alternative. Fecal samples were collected from 104 individuals with AN (restricting [ANR] and binge eating/purging [ANBP]) at admission and discharge from inpatient renourishment, and 127 non-eating disorder controls (non-ED). Food taxa were identified via metabarcoding of residual food DNA in stool. Partial least squares-discriminant analysis (PLS-DA), bootstrap validation, and linear regression characterized dietary differences and clinical associations. PLS-DA identified a dietary axis (PLS1) separating non-ED from AN (balanced accuracy ≈70%; permutation null ≈52%; PERMANOVA R²=0.024, p=0.011), forming a non-ED to ANBP to ANR gradient as expected clinically. Non-ED-associated foods included grains and red meat; AN-associated foods included soybean and lean fish. Discharge samples shifted modestly toward non-ED dietary patterns. ΔPLS1 was positively associated with weight gain (p=0.006) but attenuated after adjusting for treatment duration (p=0.458), suggesting dietary changes reflect treatment exposure rather than independently driving weight recovery. FoodSeq captures a biologically interpretable, clinically relevant dietary signature in AN that tracks treatment exposure and response, supporting its utility as a biomarker for treatment monitoring and precision nutrition interventions.

10:45

Interpersonal Synchrony In The Transmission Of Psychopathology: Mechanisms, Risks, And Clinical Opportunities
Kerstin Konrad
Aachen University and Forschungszentrum J�lich

P300

A Person-Centred And Data-Driven Approach To Phenotyping Anorexia Nervosa
Charlotte Bovenberg^{1, 2}, Johanna L. Keeler^{2, 1}, Valentina Cardi^{3, 1}, Suman Ambwani⁴, Rebecca Morris¹, Katie Rowlands¹, Janet Treasure^{1, 5}
¹Centre for Research in Eating and Weight Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, London, United Kingdom, ²Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, LVR University Hospital Essen, Essen, Germany, ³Department of Psychology, University of Padova, Padova, Italy, ⁴DIS Study Abroad in Scandinavia (DK), Copenhagen, Denmark, ⁵South London and Maudsley NHS Foundation Trust, Bethlem Royal Hospital, London, United Kingdom

Introduction Anorexia nervosa (AN) is a severe eating disorder (ED) with high mortality, marked impairment, and substantial heterogeneity. Despite extensive research, outcomes remain poor, and it is unclear why some individuals improve while others develop more persistent and severe courses. Current subtypes poorly predict illness trajectory or treatment response. This study examined phenotypic subgroups and their response to treatment. Methods Data were drawn from the TRIANGLE study, from King’s College London, of adults with AN or atypical AN receiving day- or inpatient care (n=382). Latent profile analysis identified subgroups based on anthropometric and clinical variables. Linear mixed models (n=370) assessed group differences and 18-month change in depression, anxiety, stress, work and social impairment, body mass index (BMI), and ED psychopathology. Results A four-profile solution emerged: two long-duration groups (9±7 years, highest severity; 21±11 years, moderate severity) and two short-duration groups (4±3 and 5±3 years; high vs. lower severity). The high-severity, short-duration group improved across all outcomes. The highest-severity, long-duration group improved on all except ED psychopathology. Lower-severity groups showed smaller improvements, limited to BMI and work and social functioning. Conclusions AN prognosis reflects interacting clinical, psychological, and functional factors. Subtyping should move beyond single indicators to better inform treatment planning.

P301

The Diagnostic Accuracy Of Eating Disorder Questionnaires In Adolescents And Adults Living With Higher Weight: An Updated Systematic Review
Eve T House^1,2, Caitlin M McMaster^3,4,5,6, Natalie B Lister^1,2, Isabelle R Jardine¹, Sasha J Lorien¹, Anna Lene Seidler^7,8, Hiba Jebeile^1,2
¹Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Westmead, Australia, ²Charles Perkins Centre, The University of Sydney, Camperdown, Australia, ³Sydney School of Health Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia, ⁴South Western Sydney Local Health District, Liverpool, Australia, ⁵Ingham Institute for Applied Medical Research, Liverpool, Australia, ⁶Eating Disorder and Nutrition Research Group (ENRG), Translational Health Research Institute, Faculty of Medicine, Western Sydney University, Campbelltown, Australia, ⁷Department of Child and Adolescent Psychiatry, University Medical Centre Rostock, Rostock, Germany, ⁸German Centre for Child and Adolescent Health (DZKJ), partner site Greifswald/Rostock, Rostock, Germany

Introduction: Eating disorders (EDs) and higher weight often co-occur, yet EDs may be under-recognised in people with higher weight. This review examined the diagnostic accuracy of ED questionnaires in people with higher weight. Methods: Update to a systematic review of studies published to September 2020. Five electronic databases were searched from 2020 to November 2025. Included studies reported the diagnostic accuracy of self-report ED questionnaires against a clinical interview to identify EDs and disordered eating behaviours in adolescents (≥10y) and adults with higher weight. Narrative synthesis was conducted. Results: Studies (n=32, 5 new) reported on the diagnostic accuracy of 18 questionnaires (13 in adults, 5 in adolescents). Questionnaires (8 adult, 5 adolescent) most commonly assessed binge-eating disorder. Five questionnaires in adults and none in adolescents assessed any ED. Questionnaires also assessed binge-eating/disordered eating (4 adult, 1 adolescent), loss-of-control eating (1 adult, 2 adolescent), bulimia nervosa, atypical anorexia nervosa, purging disorder, and night eating syndrome (each n=1 adult, 0 adolescent). Conclusions: There has been little progress in the validation of ED questionnaires to identify the full spectrum of EDs in people with higher weight, with particularly limited evidence for adolescents. This critical research gap must be addressed to improve early identification of ED in people with higher weight.

P302

Individual Variability For Change In Eating Disorder Symptoms Following Behavioural Weight Management Interventions Conducted With Adolescents And Adults: Findings From The Edit Collaboration
Hiba Jebeile^1,2, Sol Libesman³, Louise A Baur^1,4, Sarah P Garnett¹, Kylie E Hunter³, Isabelle R Jardine¹, Jie Kang², Rabia Khalid^1,2, Sasha J Lorien¹, Hannah Melville^1,2, David Nguyen³, Anna Lene Seidler^5,6, Natalie B Lister^1,2, on behalf of the EDIT Collaboration¹
¹Sydney Medical School, The University of Sydney, Westmead, Australia, ²Charles Perkins Centre, The University of Sydney, Camperdown, Australia, ³National Health and Medical Research Council Clinical Trials Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, Australia, ⁴Weight Management Services, The Children’s Hospital at Westmead, Westmead, Australia, ⁵Department of Child and Adolescent Psychiatry, University Medical Centre Rostock, Rostock, Germany, ⁶German Center for Child and Adolescent Health (DZKJ), partner site Greifswald/Rostock, Rostock, Germany

Introduction: Individual change in eating disorder (ED) symptoms after behavioral weight management interventions may vary. We describe change in Eating Disorder Examination Questionnaire (EDE-Q) and Binge Eating Scale (BES) scores after behavioural interventions.
Methods: Individual-level data from RCTs of behavioural interventions for adolescents and adults using EDE-Q or BES were included. We describe proportions of participants moving across cut-points between baseline and latest timepoint. Reliable Change Index was used to analyse estimated change beyond measurement error.
Results: Six adolescent (n=555, 14y, 58%F) and 15 adult (n=1,457, 46y, 78%F) trials used EDE-Q. Most remained within the same risk category (77% below cut-point; 6·6% above), 12·0% moved from above to below the cut-point, and 5·1% moved from below to above. Reliable decreases were observed for 11·4% and increases for 2·7% of participants.
Four adolescent (n=406, 15y, 60%F) and 10 adult (n=1,204, 43y, 85%F) trials used BES. Most remained within the same category (64% below cut-point; 13% above), 19% moved below the cut-point, and 3·8% moved above. Reliable decreases were observed for 10.3% and increases for 0·9% of participants.
Conclusion: Most participants remained below risk thresholds, but one in five presented above a cut-point requiring further assessment. Some participants had a reliable reduction or increase in scores. Early identification of those with increasing ED symptoms is needed.

P303

Identifying Binge Eating Disorder In Obesity Treatment: Prevalence And Screening Instruments
Malin M. Kleppe^1,2, Sigurd W. Hystad³, Hanna G. Skjåkødegård^4,5, Øyvind Rø^6,7, Paal Methlie^1,2, Yngvild S. Danielsen^8,9
¹Department of Medicine, Haukeland University Hospital, Bergen, Norway, ²Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway, ³Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Bergen, Norway, ⁴Children and Youth Clinic, Haukeland University Hospital, Bergen, Norway, ⁵Norwegian Resource Center for Eating Disorders, Bergen, Norway, ⁶Regional Department for Eating Disorders, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway, ⁷Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway, Oslo, Norway, ⁸Regional Department of Eating Disorders, Division of Psychiatry, Haukeland University Hospital, Bergen, Norway, ⁹Department of Clinical and Biological Psychology, University of Bergen, Bergen, Norway

Objective: To assess prevalence of Binge Eating Disorder (BED) in obesity care and to evaluate the validity of three patient-reported questionnaires as screening instruments. Method: Cross‑sectional study of consecutive patients referred for specialist obesity treatment (n = 276). Participants underwent a semi‑structured diagnostic interview (Eating Disorder Examination, EDE) and completed Norwegian‑translated patient‑reported questionnaires: Binge Eating Scale (BES), Eating Disorder Examination Questionnaire (EDE‑Q), and Eating Disorder Diagnostic Scale (EDDS). Sensitivity and specificity for predefined cut‑off scores were calculated using the EDE as reference standard. Results: BED prevalence was 21%, with no gender differences. Mean age was 40.2 ± 12.5 in patients with BED vs. 44.5 ± 12.5 (p = .02) in patients without BED, while BMI was 43.5 ± 6.0 vs. 42.3 ± 5.3 (p = .17). Sensitivity was 89.4% for BES (total score ≥ 18), 95.5% for EDE-Q (global score ≥ 2.5), and 20.5% for EDDS (BED DSM-5 diagnostic criteria); whereas specificity was 76.6%, 60.2%, and 95.8%, respectively. For the EDE-Q, a novel approach combining an EDE-Q global cut-off score of 2.5 with the presence of binge eating yielded a sensitivity of 90.7% and specificity of 76.6%. Conclusion: BED is common in specialist obesity care. The BES and EDE-Q showed good screening ability to rule out BED and outperformed the EDDS. However, positive screens should be followed by a diagnostic interview.

P304

Long-Term Cognitive Outcomes After Treatment Of Anorexia Nervosa: Preliminary Results
Kristin Kragh^1,3, Odin Hjemdal³, Katrine K. Fjukstad^2,3, Siri Weider^1,3
¹Eating Disorder Unit, Department of Psychiatry, Levanger Hospital, Health Trust Nord-Trøndelag, Levanger, Norway, ²Local security unit, Department of Psychiatry, Levanger Hospital, Health Trust Nord-Trøndelag, Levanger, Norway, ³Department of Psychology, the Norwegian University of Science and Technology, Trondheim, Norway

Introduction: Research has found that patients with anorexia nervosa (AN) exhibit at range of cognitive difficulties in the acute stage of the illness. There is also some evidence indicating that these difficulties are maintained after weight stabilization. However, long-term studies of cognitive function in patients with AN are scarce and it is necessary to gain konwledge about the trajectories and the characteristics of these cognitive difficulties. The current study aims to explore the trajectories of cognitive function from baseline to follow-up 6- 25 years post-admission. Methods: This study includes individuals who were previously treated for anorexia nervosa (AN) at the in- and outpatient unit of the Specialized Eating Disorder Unit at Levanger Hospital in Norway, and who have previously undergone neuropsychological assessments during the acute phase of the illness. Participants are evaluated using a comprehensive neuropsychological test battery, along with a series of self-report questionnaires measuring executive functioning, eating disorder symptoms, depression, anxiety, and quality of life. Results: Data collection is currently ongoing and preliminary results will be presented. Conclusions: This study will make a valuable contribution to the existing knowledge base on cognitive functioning in individuals with anorexia nervosa (AN), the developmental trajectories of these functions, and the predictors of cognitive outcomes.

P305

Comparative Properties Of Two Self-Report Measures Of Avoidant/Restrictive Food Intake Disorder: Psychometric And Clinical Utility
Rebecca Nicholls-Clow¹, Arianna Prudenzi¹, Glenn Waller^1,2
¹School of Psychology, University of Sheffield, Sheffield, United Kingdom, ²Department of Psychology, University of Warwick, Coventry, United Kingdom

Introduction. There is no leading self-report ARFID measure. This study compares the NIAS and the PARDI-AR-Q, to determine which demonstrates better psychometric and clinical utility. Methods. Participants (N = 156; BMI > 18.5; aged 18+) were recruited via Prolific. Data quality was screened using a short-written task. Eligible participants were invited to complete a second survey including the NIAS, the PARDI-AR-Q and other clinical measures. Exploratory factor analyses (EFAs) were conducted on each measure and combined items. Pearson’s correlations examined associations within and across measures. Clinical utility was assessed via categorical agreement between measures and correlations with clinical outcomes. Multiple regression analyses examined whether ARFID subscales predicted clinical outcomes. Results. All NIAS and PARDI-AR-Q subscales were positively correlated. The weakest association was between the NIAS Picky Eating and the PARDI-AR-Q Sensory Sensitivity subscales, supported by a four-factor solution in the combined EFA. The two measures showed moderate case agreement. NIAS subscales did not predict anxiety, depression, functional impairment, or broader eating disorder pathology. PARDI-AR-Q dimensions were consistent predictors of clinical impairment. Conclusions. The weak association between Picky Eating and Sensory Sensitivity suggests that these measures capture distinct ARFID components. The PARDI-AR-Q demonstrated greater clinical validity than the NIAS.

P306

Differences In Eating Pathology Among Transgender And Gender Diverse Adults Based On Salience Of Gender Dysphoria
Bek Urban
Virginia Commonwealth University, Richmond, VA, United States

Introduction.Gender dysphoria and shape/weight concerns are potentially overlapping influences on eating pathology among trans and gender diverse (TGD) individuals. The goal of this study was to test if the extent to which body dissatisfaction is driven by gender dysphoria or shape/weight concerns differentially impacts eating pathology in this population. Methods.TGD adults (N=908) completed the 12-item Eating Disorder Examination Questionnaire (EDE-QS) and the Trans Disordered Eating Scale (TDES). Three groups (Gender Dysphoria, Shape/Weight, and Combo) were created based on the source of participant body dissatisfaction. ANOVAs tested group differences in EDE-QS and TDES scores; logistic regression tested the influence of group on TDES ability to predict the presence of an eating disorder. Results.Group scores on EDE-QS (F(2,905)=38.95,p<.001) and TDES (F(2,905)=21.06,p<.001) were significantly different; the Combo group had the highest scores. The interaction between TDES score and group membership in the logistic regression was significant, indicating association between TDES score and the presence of an eating disorder also varies based on salience of gender dysphoria. Conclusions.The source of body dissatisfaction among TGD individuals impacts symptom severity and measurement. More research is needed to fully understand how the salience of gender dysphoria in body dissatisfaction may influence treatment and clinical outcomes.

P307

Intermittent Fasting And Eating Disorder Psychopathology: A Systematic Review
Lina Amor¹, Chloe Wong², Dasha Nicholls², Victoria Burmester²
¹Division of Psychiatry, University College, London, United Kingdom, ²Division of Psychiatry, Imperial College, London, United Kingdom

Background Intermittent fasting (IF) has gained popularity due to its physiological benefits, including weight management, immunological and metabolic health improvements. However, its association with eating disorder (ED) psychopathologies remains under-investigated. Understanding this relationship is needed to inform safe dietary practices and identify at-risk individuals. Methods The PRISMA guidance was followed. MEDLINE, Embase, and PsycInfo were searched for studies published from January 2000 to March 2025 and 7 studies identified. The CASP Systematic Review Checklist evaluated the quality of studies. Results Across 2,567 participants (~18–30 years), IF was associated with greater ED psychopathology, including higher EDE‑Q scores, binge eating, food cravings, cognitive restraint, orthorexia symptoms, and reduced intuitive eating. Six studies reported positive associations across cross‑sectional, experimental, and longitudinal designs. Samples were predominantly from Western countries. One study of fasting‑naïve individuals found no increase in ED symptoms, suggesting context and motivation may be moderators. Conclusions
IF is associated with elevated ED psychopathology. Conclusions are limited by reliance on self‑report, heterogeneous IF definitions, young female samples, and limited causal inference. Future research should use longitudinal designs, objective fasting measures, and compare health‑motivated IF with non‑weight‑motivated practices, e.g. religious fasting.

P308

Social Rejection Predicts Eating Disorder Psychopathology In Nonclinical Adolescent Females
Victoria Burmester, Chloe Wong, Dasha Nicholls
Division of Psychiatry, Imperial College, London, United Kingdom

Introduction: Social rejection is a significant stressor, particularly during adolescence, the period of peak eating disorder (ED) onset. Whether self-assessed rejection sensitivity translates into affective responses to induced ostracism, and whether social rejection predicts ED symptoms in non-clinical female adolescents is not known. Methods: 52 females aged 13-16 completed Cyberball Needs Threat Scale (NTS), the Online Offline Social Sensitivity Scale (O²S³), the Eating Disorder Diagnostic Scale-5 (EDDS-5), and the Autism Quotient-10 (AQ-10). Partial correlation and multiple linear regression were conducted, controlling for autism traits. Results: Correlations, with AQ-10 partialled out, revealed positive associations between total NTS and total O²S³(r=.37, p=.009), online (r=.38, p=.007), and offline (r=.34, p=.019) scores. Multiple regression showed NTS, O²S³and AQ-10 predicted EDDS scores (R² = .32, p <.001). Total O²S³was an independent predictor (B=.518, p=.003), whereas total NTS (B=.230, p=.104) was not. Conclusions: Self-assessed rejection sensitivity predicted ED psychopathology in non-clinical adolescent females, while induced implicit rejection did not, suggesting that subjective appraisal of rejection in everyday social contexts is more relevant to ED risk than acute responses to experimentally induced ostracism. These findings highlight rejection sensitivity as a potential target area for secondary prevention/early intervention in female adolescents.

P309

Rewiring Reward Circuits In Binge‑Eating Disorder With Combined Mdma And Glp‑1 Agonist Therapy
Vlera Fonda^1,2,3, Andrew Pospisilik⁴, Katharina Timper^1,2,5,6, Tim Gruber^1,2,3
¹Institute for Translational Metabolism Research, Helmholtz Munich, Neuherberg, Germany, ²Institute for Clinical Nutritional Medicine, Technical University of Munich, Munich, Germany, ³German Center for Diabetes Research , Neuherberg, Germany, ⁴Van Andel Institute, Grand Rapids, MI, United States, ⁵Else Kröner-Fresenius-Center for Nutritional Medicine, Technical University of Munich,, Friesing, Germany, ⁶Department Biomedicine Basel, University Hospital of Basel and University of Basel, Basel, Switzerland

Binge‑eating disorder (BED) involves recurrent intake of abnormally large amounts of palatable food with a subjective loss of control. Current treatments, including GLP‑1 receptor agonists, mainly suppress eating via satiety during dosing rather than reshaping addiction-like changes in reward circuits. Here, we show in mice that a single dose of 3,4‑methylenedioxymethamphetamine (MDMA) shift reward behaviour from binge-eating toward social interaction, an effect abolished by chemogenetic inhibition of hypothalamic oxytocin (OXT) neurons. Notably, behavioural expression of MDMA-induced social preference was strongly correlated with neuronal activation in the lateral septum, a reward-related brain region enriched for both GLP1- and OXT receptors. Guided by this anatomical evidence, we then treated binge-eating mice with a one-time injection of Semaglutide (a GLP1 analogue), MDMA+Semaglutide combination, or vehicle while being exposed to a social stimulus (conspecific); only MDMA+semaglutide produced a sustained reduction in binge-eating on re‑test two weeks later. Spatial transcriptomics of the forebrain revealed gene expression changes in Glp1r‑positive LS neurons consistent with altered synaptic and peptide signalling. MDMA+semaglutide, paired with social experience, thus recruits an oxytocin‑dependent LS circuit and lastingly reduces binge‑like eating beyond acute GLP‑1 action.

P310

Midbrain Tet1 Dosage Defines Inter-Individual Binge-Eating Susceptibility
Tim Gruber^1,2,3,4, Robert Chesters⁵, Luca Fagnocchi¹, Xinyang Yu⁶, Zhen Fu¹, Kristin Gallik¹, Heiko Backes^3,7, Robert Vaughan¹, Melanie Huber^3,8, Katharina Timper^2,3,4,9, Sylvane Desrivieres⁶, Rachel Lippert^3,5, Andrew Pospisilik¹
¹Van Andel Institute, Grand Rapids, MI, United States, ²Institute for Translational Metabolism Research, Helmholz Munich, Munich, Germany, ³German Center for Diabetes Research (DZD), Munich, Germany, ⁴Institute for Clinical Nutritional Medicine, TU Munich University Hospital, Munich, Germany, ⁵German Institute for Nutrition (DIfE), Potsdam, Germany, ⁶King's College London, London, United Kingdom, ⁷Max Planck for Metabolism Research, Cologne, Germany, ⁸Institute for Diabetes and Obesity, Helmholtz Munich, Munich, Germany, ⁹Else Kroener-Fresenius-Center for Nutritional Medicine, TU Munich, Munich, Germany

Binge-eating disorder (BED) is the most common eating disorder and carries life-altering comorbidities. While genetic and environmental risk factors have been identified, the mechanisms that determine inter-individual susceptibility remain largely unknown. Here, we demonstrate that developmental dosage of the DNA hydroxymethylase Tet1 defines inter-individual differences in binge-eating susceptibility. In mice, midbrain dopamine neurons of the ventral tegmental area (VTA) are essential for the induction of binge-eating behavior, express high levels of Tet1, and undergo rapid and widespread DNA hydroxymethylation remodeling upon experimental binge-eating. Strikingly, Tet1 haploinsufficiency creates pronounced inter-individual variation in binge-susceptibility even among genetically identical mice, which we trace to reduced connectivity between the prelimbic medial prefrontal cortex (mPFC^PL) and the VTA. Chemogenetic inhibition of mPFC^PL→VTA projections reduces binge-eating susceptibility, whereas EGR1-guided re-activation of TET1 in VTA dopaminergic neurons restores susceptibility, supporting a causal role for this axis. Importantly, TET1 promoter methylation in patients associates with binge-eating and reward-circuit function, suggesting conservation of this regulatory network in humans. Collectively, these findings identify Tet1 dosage as a novel regulator of binge-eating susceptibility and provide a mechanistic basis for how inter-individual differences in behavior are established.

P311

Targeting Dorsolateral Striatum Activity Reduces Binge-Like Eating: Pre-Clinical Evidence For A Circuit-Based Treatment Approach
Britny A. Hildebrandt, Elizabeth Crummy, Alexandra Vargas-Elvira, Susanne E. Ahmari
University of Pittsburgh School of Medicine, Pittsburgh, PA, United States

Pre-clinical approaches are essential for identifying neural mechanisms underlying binge eating (BE). The dorsolateral striatum (DLS), a key region involved in habitual behavior, is a promising target for understanding BE persistence. We investigated DLS neural activity during binge-like eating in a mouse model recapitulating core features of human BE to inform circuit-based treatment targets. Adult female mice were randomized to intermittent (2 hr/day; BE) or continuous (24 hr; control) palatable food (PF) access for 4 weeks. Single photon calcium imaging, a method for tracking in vivo neural activity in freely moving animals, was used to assess DLS activity at feeding bout onset/offset. In separate experiments, the DLS was manipulated via sustained activation (DREADDs) or closed-loop optogenetic stimulation (real-time, light-triggered neural activation) precisely at feeding bout onset. Total PF intake and feeding microstructure (licks/bouts) were assessed. Results showed that DLS neural activity was reduced at feeding bout onset in BE mice (F(60,55500) = 1.58, p= .002). Sustained DLS activation via DREADDs led to a significant reduction in total PF consumed (F (3,19) = 5.4, p = .007). Closed-loop optogenetic stimulation of the DLS at feeding bout onset significantly reduced total licks in BE mice (F(3,23) = 7.25, p = .001). Findings highlight the DLS as a driver of BE and a compelling circuit-based treatment target, showing that precise, reversible manipulation of DLS activity can reduce BE.

P312

&Ldquo;It [Eating Disorder] Makes You Less Lonely, But It Makes You Way More Lonely In The Big World&Rdquo;: A Qualitative Exploration Of The Relationship Between Loneliness And Eating Disorders In Young People
Basak Ince¹, Rosie Tatham¹, Delia Fuhrmann², Helen Sharpe³, Ulrike Schmidt^1,4
¹Centre for Research in Eating and Weight Disorders, Institute of Psychiatry, Psychology, and Neuroscience, King's College London,, London, United Kingdom, ²Department of Psychology, King’s College London, London, United Kingdom, ³School of Health in Social Science, University of Edinburgh, Edinburgh, United Kingdom, ⁴South London and Maudsley NHS Foundation Trust, London, United Kingdom

Introduction: Loneliness is common among young people and linked to poorer clinical outcomes in eating disorders (EDs). However, little is known about how loneliness and ED behaviours interact in daily life or influence recovery. This study explores young people’s experiences of this relationship and perceived support needs. Methods: Semi-structured interviews were conducted with 18 young people from the UK (aged 16–25 years) with current or past EDs. Data were analysed using thematic analysis. Results: Most participants reported loneliness preceding ED onset, often linked to identity-related factors (e.g., ethnicity, sexual orientation) and difficulties in family relationships. Participants described a self-reinforcing cycle between loneliness and ED behaviours: ED behaviours temporarily alleviated loneliness through distraction and control, while exacerbating it via withdrawal and isolation. Social withdrawal and lack of meaningful relationships enabled ED symptoms. Despite this connection, loneliness was rarely addressed in treatment. Participants valued peer support and community-based activities but cautioned that ED-focused peer support could trigger competition or distress. Conclusions: Loneliness is closely intertwined with ED experiences yet remains insufficiently addressed in care. Addressing loneliness within ED care alongside community-based peer support may facilitate recovery.

P313

Patterns Of Food Insecurity, Self-Conscious Emotions, And Eating Pathology: An Exploratory Latent Profile Analysis Among Multinational College Students
Kristina T Kumpf, Kelsey Hagan, Cate Morales
Virginia Commonwealth University, Richmond, VA, United States

Objective: Food insecurity (FI) and negative self-conscious emotions are implicated in the onset and maintenance of eating pathology. However, research on their differential contributions is limited, particularly outside of the US. Methods: Latent profile analysis identified profiles based on FI, self-conscious emotions, and self-reported EPSI Binge Eating, Purging, Cognitive Restraint, and Body Dissatisfaction in a multinational college sample (N=3,184). Profiles were compared on country and self-reported gender. Results: A 3-profile solution was identified based on AIC, BIC, entropy, and parsimony. Profile 1 (n=2118) was characterized by high pride. Profile 2 (n=649) featured high guilt, shame, and Body Dissatisfaction. Profile 3 (n=417) showed high guilt, shame, FI, and eating pathology, especially Purging. Significant differences emerged for gender and country: cisgender men and German respondents were overrepresented in Profile 1, while non-cisgender respondents were overrepresented in Profile 2. Profile 3 saw overrepresentation of cisgender women and Iranians, and underrepresentation of cisgender men, Germans, and Turkish respondents. Conclusion: FI may moderate the effect of negative self-conscious emotions on eating pathology, suggesting this relationship is not exclusive to the US food assistance system. Culture and gender differentially influence FI-related risk. Future studies are needed to investigate structural and cultural risk factors in non-Western settings, such as Iran.

P314

Neurotransmitter Concentrations In Anorexia Nervosa: Implications For Treatment
Andrea Phillipou^1,2,3, Chao Suo⁴, Caroline Rae⁵, Shawna Farquharson⁶, Susan Rossell⁷, Larry Abel⁸, Caroline Gurvich⁹, David Castle¹⁰, Tamara Simpson⁷
¹Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Australia, ²Centre for Youth Mental Health, The University of Melbourne, Melbourne, Australia, ³Parkville Youth Mental Health & Wellbeing Service, Melbourne, Australia, ⁴QIMR Berghofer, Herston, Australia, ⁵Neuroscience Research Australia, Sydney, Australia, ⁶Sydney Imaging Core Research Facility, The University of Sydney, Sydney, Australia, ⁷Centre for Mental Health & Brain Sciences, Swinburne University of Technology, Melbourne, Australia, ⁸School of Medicine, Deakin University, Geelong, Australia, ⁹HER Centre Australia, Monash University, Melbourne, Australia, ¹⁰Centre for Mental Health Service Innovation, University of Tasmania, Hobart, Australia

Introduction: The neurobiological underpinnings of anorexia nervosa (AN) remain unclear, limiting treatment options. Findings from our recent research identified square wave jerks (SWJ), a type of atypical eye movement, as a promising biomarker/endophenotype for AN. The presence of SWJs suggests differences in gamma-aminobutyric acid (GABA) and glutamate (Glu) concentrations in individuals with AN; and the aim of this study was to investigate these differences in relevant brain regions. Methods: Data from 75 female participants, including 19 current anorexia nervosa (c-AN), 19 weight-restored from anorexia nervosa (wr-AN), 17 biological sisters of people with anorexia nervosa (AN-sis), and 20 aged matched healthy controls (HCs), underwent magnetic resonance spectroscopy of the superior colliculus and supramarginal gyrus. Results: c-AN were found to have higher GABA levels in the superior colliculus compared to wr-AN and AN-sis, and the supramarginal gyrus compared to AN-sis (Cohen’s d’s = 0.5-0.6). Glu levels were lower in the supramarginal gyrus in c-AN compared to wr-AN and HC, and lower in AN-sis relative to HC (Cohen’s d’s = 0.7-0.9). Conclusions: The findings suggest that differences in GABA and Glu concentrations in the superior colliculus and supramarginal gyrus may relate to the atypical eye movements observed in AN, and provide support of the neurobiological basis of this biomarker/endophenotype that can be targeted in future treatment trials.

P315

Characterizing The Prodromal Phase Of Anorexia Nervosa Through Laboratory Data
Manchu U. Thangavelu¹, Ole S. Schwartz¹, Sara Schwartz^1,2, Janne T. Larsen¹, Loa Clausen^1,2, Liselotte V. Petersen¹, Zeynep Yilmaz^1,3
¹Aarhus University, Aarhus, Denmark, ²Aarhus University Hospital , Aarhus, Denmark, ³University of North Carolina , Chapel Hill, NC, United States

Introduction: Anorexia nervosa (AN) is a severe psychiatric disorder with profound multisystem complications and high mortality. Diagnosis relies largely on overt behavioural and anthropometric features, while biological changes preceding diagnosis remain poorly understood. Laboratory data may offer insights into the prodromal phase of AN. Methods: Using Danish Registers, 3930 AN cases aged 10 years or older between 2013-2022 were identified and matched with controls on age, sex, and region of residence. Laboratory tests from the two years preceding diagnosis were extracted from the LABKA database, where analyses were restricted to GP-requested tests to reduce indication bias. Testing patterns and trajectories were assessed using mixed-effect models and inflection point analysis. Results: Preliminary analyses showed a higher testing burden in cases than controls and a steeper increase in testing over time (IRR: 1.09, p<2e-16). Both the testing intensity and overall testing burden increased before AN diagnosis (~6 months and ~4 months prior, respectively), suggesting a potential escalation phase. Notably, only ~50% of cases underwent testing in the month preceding diagnosis, indicating heterogeneous healthcare contact prior to diagnosis. Conclusion: AN diagnosis was preceded by increased laboratory testing, suggesting a pre-diagnostic shift in healthcare utilization. Characterizing such trajectories may improve understanding of symptom evolution and inform future strategies for earlier detection.

P316

Getting Worse, Before Getting Better? &Lsquo;Recovery&Rsquo; As A Risk Period For Suicide In Eating Disorders
Rachel E. Whyte, Una M. Foye, Tom D. Jewell, Moritz P. Herle
King's College London, London, United Kingdom

Introduction: People with eating disorders (EDs) are at increased risk of suicide. Recent qualitative research suggests that ED recovery may involve heightened suicide risk, despite the assumption it represents clinical improvement. As such, there is limited evidence-based guidance to reduce suicide risk during recovery. This study aims to understand the relationship between ED recovery and suicidality in UK adults. Methods: This mixed methods online survey is currently open to recruitment, with a final target sample size of 200. Participants are eligible if they are 18+, reside in the UK and have experience of ED recovery. The online survey explores experiences of suicidality during an active ED and phases of recovery (e.g. first 3 months, 3-6 months etc). Quantitative data will be analysed using group comparisons and predictive models to quantify associations between different phases of ED recovery and suicidality. Exploratory analyses will investigate associations with participant characteristics such as ED diagnosis. Qualitative data will be analysed using reflexive thematic analysis. Results: The results will integrate quantitative and qualitative data to provide insight into experiences of suicidality across the ED recovery journey. Conclusions: This study can inform clinical care and future research by identifying periods of heightened risk for suicidality across ED recovery and offer insight into the mechanisms underpinning low long-term recovery and high relapse rates.

P317

Adapting Eating Disorder Focused Family Therapy For Autistic Children And Young People With Anorexia: A Delphi Study To Support Development Of Evidence Informed, Co-Produced Clinical Guidelines.
Fiona Duffy^1,2,3, Saffron Baldoza³, Julian Baudinet^4,5, Ian Birch³, Emma Broadhurst³, Gina Dimitropoulos^6,7, Clare Ellison⁸, Karri Gillespie Smith^1,3, Rachel Loomes^4,9, Umairah Malik¹⁰, Ellen Maloney^1,3, Lorraine Small², Kate Tchanturia^3,5,11, Iona Thomas-Yates¹, Freya Nash¹, Amelia Austin^1,3,12
¹Department of Clinical Psychology, University of Edinburgh, Edinburgh, United Kingdom, ²NHS Lothian CAMHS, Edinburgh, United Kingdom, ³Eating Disorder and Autism Collaborative, Edinburgh, United Kingdom, ⁴Maudsley Centre for Child and Adolescent Eating Disorders, South London and Maudsley NHS Trust, London, United Kingdom, ⁵Department of Psychology Medicine, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom, ⁶Faculty of Social Work, University of Calgary, Calgary, AB, Canada, ⁷Mathison Centre of Mental Health Research and Education, University of Calgary, Calgary, AB, Canada, ⁸Cumbria. Northumbria, Tynne and Wear NHS Foundation Trust, England, United Kingdom, ⁹Department of Clinical, Educational and Health Psychology, Kings College London, London, United Kingdom, ¹⁰Beat eating disorders, Norwich, United Kingdom, ¹¹Department of Psychology, Ilia State Unviersity, Tbilisi, Ghana, ¹²Department of Psychology, Glasgow Caledonia University, Glasgow, United Kingdom

Introduction: Autistic children and young people with anorexia nervosa (AN) receiving eating disorder focused family therapy (FT-ED) have poorer treatment outcomes than non-autistic peers (Nimbley et al., 2025; Bentz et al., 2022, Stewart et al, 2017). Alongside parents/carers, they report treatment experiences that are inflexible and mis-attuned to autistic needs (Nimbley et al., 2026; Alford et al., 2025). The study aimed to produce clinical guidelines to support FT-ED clinicians in the adaptation of care for Autistic children and young people. Methods: Evidence-informed, co-produced clinical guidelines were developed through workshops with Autistic individuals with lived experience, parents/carers, clinicians, researchers, and third sector representatives. An embedded Delphi process was used to establish consensus. Results: Guidelines recommended a strengths based, collaborative approach; early screening for autism; developing a shared understanding of autism and the ED; education on how autistic profiles interact with disordered eating; adapting the physical environment, food/meal plans, and communication; sensitive use externalisation; flexibility in treatment pace and format; advanced notice of change/endings; and reflective practice to balance fidelity and adaptation. Conclusion: These guidelines support clinicians in confidently adaptating FT-ED for Autistic young people with AN and their families. They may also help families advocate for autism-affirming care.

P318

Time To Notice Neurodiversity In Eating Disorder Services: A Three-Year Real-World Analysis Of Autism, Adhd, And Audhd
Lauren Makin^1,2, Karina Allen^1,3, Kate Tchanturia^1,3,4
¹King's College London, London, United Kingdom, ²NIHR Maudsley Biomedical Research Centre, London, United Kingdom, ³South London and Maudsley NHS Foundation Trust, London, United Kingdom, ⁴Ilia State University, Tbilisi, United Kingdom

Introduction: Autism and ADHD frequently co-occur and are overrepresented in eating disorder (ED) services, where they are linked to poorer treatment experiences and outcomes. Autistic and ADHD patients with EDs also present with greater ED psychopathology and psychological distress, and Autistic patients report greater functional difficulties. However, no study has directly compared patients with EDs who are both Autistic and ADHD (AuDHD) with Autistic-only, ADHD-only, or ‘Neither’ patients. Methods: This cross-sectional observational study analysed three years of routinely collected intake data from a specialist adult ED service. ED psychopathology (EDE-Q), psychological distress (CORE-10), and work and social functioning (WSAS) were compared across patients reporting suspected or known Autism, ADHD (or ADHD medication use), both, or neither. No hypotheses were specified. Results: Of 1,252 patients, 32 (2.6%) were AuDHD, 45 (3.5%) Autistic-only, and 81 (6.5%) ADHD-only. Differences were small but consistent. EDE-Q scores were highest in ADHD-only (M=4.24), and CORE10 and WSAS scores were highest in AuDHD (M=24.16 and 26.56). All three measures were lowest in Neither (M=3.85, 20.10, and 20.06). Conclusion: Autistic and/or ADHD patients with EDs show greater psychological distress and poorer functioning, particularly when both are present. ED psychopathology is also higher, especially in ADHD patients. Early identification and person-centred care may help improve outcomes.

P319

Lived Experience Perspectives Of Various Self-Damaging Behaviors: A Thematic Analysis Of The Co-Occurrence Of Non-Suicidal Self-Injury And Disordered Eating.
Bernou Melisse^1,2,3,4, Mirthe Luijsmans^1,5, Janske van Eersel^5,6, Glenn Kiekens^1,7
¹Department of Medical and Clinical Psychology, University of Tilburg, Tilburg, Netherlands, ²Co-eur, Utrecht, Netherlands, ³Department of Clinical Psychology, Utrecht University, Utrecht, Netherlands, ⁴American Center for Psychiatryand Neurology, Abu Dhabi, United Arab Emirates, ⁵Center for Contextual Psychiatry, Faculty of Biomedical Sciences, KU Leuven, Leuven, Belgium, ⁶Department of Human Resources Studies, Faculty of Social and Behavioural Sciences, Tilburg, Netherlands

Background. Non-suicidal self-injury (NSSI) and disordered eating (DE) frequently co-occur, creating clinical challenges as reductions in one behavior may mirror the other. We aim to understand the perspectives of individuals with lived experience on the meaning of these comorbid self-damaging behaviors. Methods. Interviews with twenty individuals with lived experience focused on perceived similarities and differences between NSSI and DE were thematically analyzed. Results. Three themes were identified. First, ‘a secret identity built on self-depreciative beliefs’ captured how NSSI and DE were viewed as private, identity-defining behaviors grounded in deserved pain and inadequacy. Second, ‘a search for control and regulation on different timescales’ described how restrictive eating functioned as a sustained strategy offering a permanent sense of structure and control. NSSI, binge eating, and vomiting served acute in-the-moment regulation offering temporary control. Third, ‘micro and macro influences’ captured how intra- and interpersonal micro-level factors linked to both behaviors, with social comparison and body-image ideals being more pronounced for DE. At the macro-level, restrictive eating was framed as culturally acceptable, whereas NSSI, binge, eating, and vomiting were described as stigmatized. Implications. A transdiagnostic focus and shared understanding of NSSI and DE to address underlying needs and inform prevention and intervention are important.

P320

Unravelling The Association Between Polycystic Ovary Syndrome And Eating Disorders
Marie-Christine Opitz, Michelle Carrol, Fiona Duffy, Katie Marwick, Helen Sharpe
University of Edinburgh, Edinburgh, United Kingdom

Introduction: Polycystic Ovary Syndrome (PCOS) can impact the onset, maintenance, and recovery of Eating Disorder (ED) symptoms through dysregulated food intake (i.e., hormonal imbalances), visible bodily differences (i.e., weight/shape, excess hair, acne), and treatment approaches (i.e., weight management). However, no study so far has qualitatively investigated how co-occurring PCOS and ED symptoms impact each other and clinical outcomes in both conditions. Methods: One-on-one interviews were combined with subsequent focus group discussions to explore the lived experiences of N=15 UK-based adults with PCOS and EDs/disordered eating. Interpretative Phenomenological Analysis was used to investigate individual experiences and contextual factors. Follow-up focus group discussions allowed for the exploration of common themes. Results: Co-occurring PCOS and ED symptoms were seen as directly linked (especially in regards to weight and treatment approaches), as complicating symptom management, and/or influencing diagnoses. A lack of health education and support for both PCOS and ED symptoms were perceived as reinforcing stigma and negative (mental) health outcomes. Conclusion: Screening for and adapting treatment approaches in co-occurring PCOS and ED symptoms could help identify treatment barriers for both conditions and improve overall wellbeing. Evidence-based support resources for health professionals and patients are needed to enhance health communication and health outcomes.

P321

Articulating Distinctions In Distribution Of Eating Disorder Diagnoses And Disordered Eating Behaviors Among Individuals With Neurodiverse Identities
Meg Salvia
Boston University, Boston, MA, United States

Eating disorders (EDs) are increasingly recognized among neurodivergent individuals, yet research often silos specific overlaps (e.g., autism/ARFID, ADHD/binge eating) and overlooks broader, heterogeneous presentations. This study describes the prevalence of co-occurring EDs and neurodevelopmental conditions and evaluates associations between ED behaviors, weight concerns, and neurodivergence. We analyzed 8 years (2017–2025) of cross-sectional data from the Healthy Minds Study. The sample included 719,237 U.S.-based university students with self-reported mental health diagnoses, of which, a subset (n=15,966) also completed a module with questions specific to disordered eating and weight concern. In preliminary results, overall neurodevelopmental diagnoses prevalence was 6.3% ADD, 1.3% autism, and 0.3% intellectual disability (ID). While AN was the most frequent ED diagnosis (2.1% vs. ~1% for BN, BED, ARFID), binge eating was the most common behavior (3% weekly). Co-occurrence was high across all EDs: among students with ARFID (n=8,440), 23% reported ADD, 8% autism, and 2% ID. Similar overlaps were observed for BED (24% ADD, 5% autism, 2% ID), AN (19% ADD, 5% autism, 2% ID), and BN (19% ADD, 4% autism, 2% ID). Neurodevelopmental diagnoses co-occur at high, comparable rates across the full spectrum of EDs . These findings underscore the critical need for inclusive ED screening and treatments adapted for diverse executive functioning, communication, and learning profiles.

P322

The Prevalence Of Comorbidity Of Avoidant/Restrictive Food Intake Disorder And Intellectual Disability In Children: A Systematic Review And Meta-Analysis
Elisabet Wentz^{1, 2}, Selman Yildirim³
¹Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg,, Gothenburg, Sweden, ²Region Vastra Gotaland, Department of Neuropsychiatry, Sahlgrenska University Hospital,, Gothenburg, Sweden, ³Department of Clinical Science, Umeå University, Umeå, Sweden

Objectives: Empirical evidence indicates comorbidity between avoidant/restrictive food intake disorder (ARFID) and intellectual disability (ID), yet data remain limited. This systematic review and meta-analysis aimed to determine the prevalence of ID among children with ARFID and the prevalence of ARFID among those with ID. Methods: The review was conducted in accordance with the PRISMA guidelines. Studies were identified from PsycINFO, MEDLINE, and Google Scholar published between 2010 and 2025 using predefined search terms. Meta-analyses of proportions were conducted using a random-effects model with restricted maximum likelihood estimation. Results: Nine eligible studies were identified comprising 1,378 children and adolescents diagnosed with ARFID. Seven studies were conducted in clinical settings, 2 in community samples. The 7 clinical studies included 1,306 participants, with an ID prevalence of 4.2-29.1%. Two community-based studies identified lower rates, 0.0 - 4.1%. ARFID patients with comorbid ID were predominately males (66.6-81.8%). The pooled prevalence of ID among ARFID cases was 9%. No studies reported the prevalence of ARFID in children with ID. Conclusions: This systematic review and meta-analysis demonstrates that the relationship between ARFID and ID is an understudied topic in the literature. The findings indicate that ID is significantly co-occurring with ARFID, particularly in clinical samples. Boys are overrepresented among those with ARFID and comorbid ID.

P323

A Latent Profile Analysis Of Within-Person Nightly Sleep Profiles In Adolescent Girls With Binge-Spectrum Eating Disorders
Stephanie Manasse¹, Madeline Navea¹, Jannah Moussaoui², Laura D'Adamo^1,3
¹Center for Healthcare Delivery Science, Nemours Children's Health, Wilmington, DE, United States, ²Washington University at St. Louis, St Louis, MO, United States, ³Drexel University, Philadelphia, PA, United States

Introduction. Sleep disturbance is increasingly linked with binge eating (BE). An examination of nightly sleep types in adolescents with BE would lend critical information to the types of sleep interventions that may impact BE. Method. We conducted a 3-week ecological momentary assessment (EMA) study in which adolescent girls with at least once-weekly BE (ages 14-19, n=58) completed a daily sleep diary. We conducted a latent profile analysis on nightly within-person sleep (sleep duration, efficiency and self-reported sleep quality and tiredness). Results. A 4-class latent solution was selected based on fit indices (AIC, BIC) to classify profiles of nightly sleep. Class 1 (“great sleep;” 33.5% of nights) was characterized by high sleep duration, efficiency, quality and low tiredness; Class 2 (“poor sleep;” 10.6% of nights) was characterized by low duration, efficiency, and quality, and high tiredness; Class 3 (“subjectively sleepy;” 30.6% of nights) was characterized by average duration and efficiency but high tiredness and low quality; and Class 4 (“positive perceptions;” 25.3% of nights) was characterized by average duration and efficiency but low tiredness and high quality. On average, participants experienced 3.47 (SD=0.71) sleep profiles. Conclusion. Nightly sleep in adolescents with BE is highly heterogeneous. Investigations into relations between nightly sleep patterns and subsequent BE (and vice versa) are needed to inform interventions.

P324

The Overlap Between Self-Reported Disordered Eating In A Uk Longitudinal Cohort And Eating Disorder Diagnoses In Electronic Health Records
Benjamin Geers¹, Tamsin Newlove-Delgado¹, Ilaria Costantini², Francesca Solmi², Helen Bould^3,4
¹Children and Young People's Mental Health Research Collaboration (ChYMe), Department of Public Health and Sports Sciences, University of Exeter Medical School, Exeter, United Kingdom, ²Division of Psychiatry, University College London, London, United Kingdom, ³NIHR Bristol Biomedical Research Centre, University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, Bristol, United Kingdom, ⁴Gloucestershire Health and Care NHS Foundation Trust, Gloucestershire, United Kingdom

Introduction. It is unclear how many adolescents with disordered eating receive a clinical diagnosis. We used the Avon Longitudinal Study of Parents and Children (ALSPAC), linked to primary and secondary care records, to examine overlap between questionnaire-derived disordered eating, self-reported diagnosis/treatment, and linked eating-disorder clinical events. Methods. Questionnaire data at ages 14, 16, 18 and 24 were used to derive Diagnostic and Statistical Manual (DSM) severity disordered eating behaviours from fasting, purging, binge eating and excessive exercise. Linked eating-disorder clinical events were identified between ages 13 and 24 from primary care, Hospital Episode Statistics, and Mental Health Services Data Set records. Wave-specific prevalence and overlap were described. Results. Among responders, 5,843 at age 14 and 4,228 at age 24 had sufficient data. From ages 14 to 24, DSM-severity disordered eating behaviour increased from 4.8% to 11.1%, self-reported diagnosis from 0.5% to 4.0%, and treatment from 0.6% to 6.5%. Ninety-nine participants had ≥1 eating-disorder clinical event in linked healthcare records. Linked clinical events were more common in those with disordered eating behaviours across waves; at age 16 this was 5.8% vs 0.9%, with greater overlap for self-reported diagnosis and treatment. Conclusions. Structured healthcare records captured few adolescents with DSM-severity disordered eating behaviours, suggesting under-ascertainment in healthcare records.

P325

Health Services Utilization Of Individuals With Eating Disorders In Primary And Specialized Care In Norway
Anne Martina Kraus¹, Deborah Lynn Reas², Hege Marie Gjefsen¹, Øyvind Rø^2,3,, Katrine Damgaard Skyrud¹
¹Division for Health Services, Norwegian Institute of Public Health , Oslo, Norway, ²Regional Department for Eating Disorders, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway, ³Insitute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway

Objective: This register-linkage study investigated primary and specialized healthcare utilization among individuals with an eating disorders (ED). Method: Data were retrieved from the Norwegian Patient Registry and the Control and Payment of Health Reimbursements. Individuals aged 6-69 years registered with a primary ED diagnosis (ICD-10) between 2015 and 2020 were included. Treatment cycles were defined as a sequence of specialist contacts preceded by and followed by a 48-month lag period. Treatment duration from diagnosis to end-of-treatment was assessed using time-to-event analysis. Results: 10,782 had a primary ED diagnosis; 91.8% female and 8.2% male. Nearly half (48.3%) were diagnosed with AN (F50.0-50.1), 28.7% other EDs (F50.4-50.9), and 23% BN (F50.2-50.3). Overall, 53% of patients had a comorbid psychiatric diagnosis, most frequently mood (29.7%) and anxiety (29.2%). Median treatment duration was 3.1 yrs for AN, 1.6 yrs for BN and 1.3 yrs for other ED. Within two years of the ED diagnosis, 29.7% had received inpatient care (md 56 days), while 3.5% received day treatment. The median number of annual GP consultations was 9.5 visits, and 67% were coded as somatic-related. Patients under 18 yrs accounted for 32.3% of treatment cycles, mostly for AN (67.9%); adult treatment was distributed across diagnoses (38.7% AN, 30.7% BN and 30.5% other ED). Conclusion: Individuals with EDs exhibited substantial utilization of primary and specialized care, with notable variable by age and diagnosis.

P326

The Role Of Age Of Onset On Medication Use In Anorexia Nervosa
Birgitte D. Semark^1,2, Loa Clausen^3,4, Esben Agerbo¹, Liselotte V. Petersen¹, Zeynep Yilmaz¹
¹National Centre for Register-based Research, Department of Public Health, Aarhus University, Aarhus, Denmark, ²Centre for Integrated Register-based Research, CIRRAU, Aarhus University, Aarhus, Denmark, ³Department of Child and Adolescent Psychiatry Aarhus University Hospital, Aarhus, Denmark, ⁴Department of Clinical Medicine, Aarhus University, Aarhus, Denmark

Introduction: Anorexia nervosa (AN) is usually diagnosed during teenage years or into early adulthood, but neither earlier nor later onset is rare. Although pharmacotherapy is not the first-line treatment, previous research has shown higher medication use in individuals with AN compared to matched controls, with and without comorbidities. This project aims to describe the medication use patterns before and after time of diagnosis in individuals with AN depending on age at first diagnosis.
Methods: Our sample includes all individuals diagnosed with AN between 1998 and 2018 using the Danish registers. To describe the general patterns, we used generalized linear mixed models on age groups (early-, typical- and late-onset) and year to see any changes over time. To examine trends of specific medications, the PRE2DUP method and group-based trajectory modelling were used to evaluate differences between age groups.
Results: We identified 11.150 individuals diagnosed with AN, 76% were diagnosed in the typical age range (13-25 years), whereas 3% had an earlier (<13 years) and 20% a later onset (>25 years). Analyses are ongoing, but preliminary results suggest a significant increase in psychotropic medications after AN diagnosis in all age of onset groups.
Conclusion: We anticipate that our findings will further the understanding of how and why pharmacotherapy is used in AN at the current rate, which could have important clinical implications on the management of AN and comorbidities.

P327

Prevalence Of Disordered Eating And Eating Disorders In Midlife Men And Women: Findings From A Finnish Twin Study
Mark T. Turunen¹, Sari S. Aaltonen^2,3, Anna Keski-Rahkonen¹, Pyry N. Sipilä¹
¹Department of Public Health, University of Helsinki,, Helsinki, Finland, ²Institute for Molecular Medicine Finland FIMM, University of Helsinki, Helsinki, Finland, ³Department of Psychiatry, University of Helsinki, Helsinki, Finland

Introduction: Disordered eating and eating disorders are prevalent across the lifespan, but research has focused mainly on adolescence and young adulthood. This study aimed to determine the prevalence of disordered eating and eating disorders among midlife men and women in the general population in Finland. Methods: FinnTwin16 is a population-based longitudinal study of twins born in 1974–1979 The midlife dataset contains 2529 individuals (60% female) with a mean age of 47.2 (range 44.5–50.0) who self-reported eating disorder diagnoses and disordered eating behaviours. Results: Altogether, 2.8% of participants, 4.2% of women and 0.6% of men, self-reported a medically diagnosed eating disorder. In contrast, disordered eating was far more prevalent: overeating was reported by 24.1% of women and 22.2% of men, restrictive eating by 6.9% of women and 2.9% of men, and alternating overeating and restricting by 3.0% of women and 1.4% of men, respectively. Conclusions: Although medical eating disorder diagnoses were relatively rare, a significant proportion of both men and women self-reported disordered eating behaviours in midlife, with overeating being particularly common. Improved recognition of eating disorders and access to services is important also beyond adolescence.

P328

What About Menopause In Seed?
Barbara Mangweth-Matzek¹, Karin Mautner¹, Hannah Weponer², Katharina Feil²
¹Psychiatry II, Department of Psychiatry, Psychotherapy, Psychosomatic and Medical Psychology, Innsbruck, Austria, ²Gynecological Endocrinology and Reproduction Medicine, Medical University Innsbruck, Innsbruck, Austria

Object: Little is known about chronic eating disorders (ED) and menopause.This study aimed to assess menopausal symptoms in women with SEED compared to women in remission and healthy controls. Method: The index-group included 95 patients with anorexia nervosa or bulimia nervosa with an average illness duration of 14 years and middle age (18-68). Questionnaires and a structural interview were used to assess demography, health, eating behavior including eating disorders, menstruation and menopausal symptoms. Results: Patients with ED were on average 35 years, mostly high educated and without children similar to both comparing groups. With regard to menstruation-/ menopausal-status 33% of them reported long enduring amenorrhea which differed significantly from the remitted (8%) and the control women (2%). Focusing on menopausal symptoms, women with SEED reported significantly higher frequencies of every menopausal symptom as both comparing groups. Further, there were no differences within the age-groups regarding the symptoms of sweating/hot flashes, vaginal dryness, bladder problems and sexual problems as most specific menopausal symptoms. Conclusion: Our results suggest that women with SEED frequently present with menopause-like symptoms that are not caused by chronological ovarian aging but rather by functional hypothalamic hypogonadism and estrogen deficiency related to the eating disorder. This condition does not represent true menopause but a reversible hypoestrogenic state.

P329

Barriers And Challenges In Eating Disorder Care: A Qualitative Study Of Brazilian Psychiatrists&Rsquo; Perspectives
Mireille C. Almeida^1,2, Maria A. Pedrosa^1,3,4, João C. Hiluy^1,5,6, Patrícia P. Lemos ^1,7, Márcia Assunção⁸, Maria A. Peres⁸, Maria A. Nunes^1,9, Táki Cordas^1,4, Adriano Segal^1,10,11, Denise Cardoso¹, Antônio Geraldo¹, José C. Appolinario^1,5,11
¹Eating Disorders Committee of the Brazilian Psychiatric Association (ABP), Rio de Janeiro, Brazil, ²Department of Mental Health, Faculdade de Ciências Médicas da Santa Casa de São Paulo (FCMSCSP), São Paulo, Brazil, ³Department of Alcohol and Drugs at Instituto Perdizes - Universidade de São Paulo (USP), São Paulo, Brazil, ⁴Eating Disorders Program AMBULIM, Universidade de São Paulo (USP), São Paulo, Brazil, ⁵Obesity and Eating Disorders Group (GOTA), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil, ⁶Unichristus University Center, Fortaleza, Brazil, ⁷Departamento de Psiquiatria, Faculdade Zarns, Salvador, Brazil, ⁸Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil, ⁹Programa de Pós-Graduação em Epidemiologia, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil, ¹⁰Obesity and Metabolic Syndrome Outpatient Service, Endocrinology and Metabolism Department, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil, ¹¹Psychiatry and Eating Disorders Department at the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO), São Paulo, Brazil

Objective: Despite the rising prevalence of eating disorders (ED), specialized care remains scarce, particularly in low- and middle-income countries. This study examines the perspectives and challenges faced by Brazilian psychiatrists in ED treatment, highlighting both systemic and individual barriers. Method: A qualitative, descriptive, and exploratory study was conducted using an online survey distributed to members of the Brazilian Psychiatric Association (ABP). Open-ended responses from 191 psychiatrists were analyzed using ALCESTE software. Textual data underwent Descending Hierarchical Classification (DHC) to identify stable lexical classes and thematic axes. Results: Three stable classes emerged, organized into two axes: (1) Lack of experience and necessity of referral to specialists; and (2) Barriers and limitations in ED treatment, highlighting insufficient training and unavailability of multidisciplinary teams. Participants reported a lack of specialized services within the Brazilian public health system (SUS) and expressed significant insecurity in managing ED. Discussion: These findings underscore a critical gap between the rising demand for ED treatment and the professional readiness of psychiatrists in Brazil. Concentrated specialized units in urban centers and a lack of specific public policies drive healthcare disparities. Urgent improvements in medical education regarding EDs and the expansion of structured, multidisciplinary networks are essential for better patient outcomes.

P330

Expereinces Of Access And Use Of Glp-1 In Uk Adults With Eating Disorders
Fiona Duffy^1,2,, Emy Nimbley^1,3, Abi Pickard¹, Michelle Caroll¹, Sukrayie Akar¹, Lauren Bruha¹
¹Department of Clinical Psychology, University of Edinburgh, Edinburgh, United Kingdom, ²NHS Lothian CAMHS, Edinburgh, United Kingdom, ³ School of Health and Wellbeing University of Glasgow, Glasgow, United Kingdom

GLP-1s are increasingly used for weight management in health and general population settings, raising concerns about potential misuse among individuals with disordered eating or negative impact. Equally there has been interest raised in the potential role of GLP-1 in binge eating. This study aims to explore experiences and perceived impact of GLP-1 use, and examine routes to accessing GLP-1 in a mixed eating disorder population in the UK. Thirteen adult participants (76% female, 92% white) were recruited via social media for an online semi-structured interview. Participants identified with a range of eating disorders (BED: 38%, AN: 23%, BN: 15%, EDNOS: 7%, mixed presentation 15%). Data was analysed using Reflexive Thematic Analysis. Analysis is still being conducted but provisional themes surround 1) Motivational conflict between medical and eating disorder needs, 2) Double Edged Sword (benefit and risk), 3) Care vs Commerce 4) Stigma and Public Perception. The study highlights critical areas of concern around commercialisation, regulation and follow up care via private GLP-1 prescribers in the UK. It also navigates a balance of positive impact on ED symptoms for some individuals and potential misuse or reinforcement of overevaluation of weight and shape-based cognitions for others. Finally it highlights the impact of normalisation of GLP-1 use in our culture on eating disorder presentations.

P331

Identification And Management Of Binge-Eating Disorder And Bulimia Nervosa In Primary Care Settings: A Qualitative Systematic Review Of Healthcare Professionals' And Patients' Perceptions
Stella Kozmér^1,2, Christopher O'Rouke³, Natalia S. Lawrence⁴, Jane R. Smith¹, Samantha B. van Beurden¹
¹University of Exeter Medical School, University of Exeter, Exeter, UK, Exeter, United Kingdom, ²Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom, ³Dorset Healthcare NHS University Foundation Trust, Bournemouth, UK, Bournemouth, United Kingdom, ⁴Department of Psychology, University of Exeter, Exeter, UK, Exeter,

Objective: To understand perceptions of patients and healthcare professionals (HCPs) on the identification and management of binge-eating disorder (BED) and bulimia nervosa (BN) in primary care settings, and how rates of identification and referral for support may be improved. Methods: A systematic review of qualitative studies was conducted. Eight databases were searched in August 2025. Studies were excluded if they focused on secondary or tertiary care, patients under the age of 16, or anorexia nervosa. Data on sample, type of eating disorder, and country were extracted, and thematic synthesis was used to synthesise the data. Results: Twenty-five studies were included. Four articles were of high quality; the rest (N=21) were medium with a moderate risk of bias. Most studies were from the UK (N=9), with 14 focusing on HCPs' and 13 on patients' perspectives. The main factors influencing the identification and management of BED/BN were identified to be knowledge and understanding of the conditions, healthcare professional–patient interactions, attitudes and emotions toward BED/BN and the healthcare system, and the existence and accessibility of treatment and referral pathways. Discussion: The interaction of these factors is discussed in relation to the literature, and gaps in research and clinical practice are identified, such as a limited separation of eating disorder categories, which could help inform the development of strategies to improve the identification and management of BED/ BN.

P332

Lived Experience, Carer, And Clinician Perspectives On The Development, Maintenance, And Recovery From Eating Disorders
Stephanie Miles^1,2, Kathleen de Boer³, Courtney P. McLean⁴, Genevieve Pepin⁵, Kamryn T. Eddy^6-7, Shannon Calvert⁸, Dominic Dwyer^1,2, Caroline Gao^1,2,10, Erica Neill^1,2,9, Andrea Phillipou^1,2,9
¹Orygen, The National Centre of Excellence in Youth Mental Health, Melbourne, Australia, ²Centre for Youth Mental Health, The University of Melbourne, Melbourne, Australia, ³Department of Psychological Sciences, Swinburne University of Technology, Melbourne, Australia, ⁴School of Psychological Sciences, Monash University, Melbourne, Australia, ⁵School of Health and Social Development, Deakin University, Geelong, Australia, ⁶Eating Disorders Clinical and Research Program, Massachusetts General Hospital, Boston, MA, United States, ⁷Department of Psychiatry, Harvard Medical School, Boston, MA, United States, ⁸National Eating Disorders Collaboration, Melbourne, Australia, ⁹Parkville Youth Mental Health & Wellbeing Service, Melbourne, Australia, ¹⁰School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia

Introduction: Developing a holistic understanding of eating disorders (EDs) requires attention to multiple perspectives. This study explored how individuals with lived experience of an ED, carers, and clinicians understand factors influencing development, maintenance, and recovery from EDs. Methods: Twelve adults with lived experience, nine carers, and twelve clinicians participated in one of six focus groups (two focus groups run per participant group). Data were analysed using reflective thematic analysis. Results: Common themes identified across the groups related to the development and maintenance of EDs (e.g. EDs acting as a coping mechanism, personality characteristics (such as perfectionism) increasing vulnerability) and factors promoting recovery (e.g. connection to others and building a meaningful life beyond the ED). Differences also emerged between groups: genetics were identified as a contributing factor by lived experience and clinician groups, whereas carers and clinicians emphasised barriers to accessing appropriate, timely care as contributing to ongoing illness. Conclusions: Findings highlight both shared and distinct perspectives on EDs and provide direction for future research aiming to better understand what contributes to the development, maintenance, and recovery from EDs. Incorporating these insights may strengthen prevention and care approaches by supporting more responsive, person-centred, and context-aware interventions.

P333

Comparative Effects Of Bmi And Body Fat Percentage On Disordered Eating Symptoms In Adolescent Boys And Girls
Ronan Scott, Kristen M. Culbert, S. Alexandra Burt, Kelly L. Klump
Michigan State University, East Lansing, MI, United States

Introduction. Higher body mass index (BMI) is associated with disordered eating (DE); however, BMI imprecisely measures body composition by indexing body size without distinguishing fat from lean mass. Body fat percentage (BF%) is a more specific index of adiposity and, within sociocultural contexts that idealize leanness, may better predict DE. This study examined the overlapping and distinct associations of BMI and BF% with DE in adolescents. Methods. Participants were 280 boys and 1,313 girls (N=1,593) from the Michigan State University Twin Registry. In-lab height and weight measurements were used to calculate age/sex-adjusted BMI percentiles. BF% was assessed via bioelectrical impedance analysis. DE symptoms (body dissatisfaction, binge eating, dietary restraint, weight preoccupation) were assessed with validated self-report questionnaires. Analyses adjusted for age and pubertal status. Results. BMI and BF% had similar associations with all DE variables in both sexes. Accounting for shared variance, BMI remained significantly and moderately associated with body dissatisfaction, dietary restraint, and weight preoccupation, whereas BF% showed only modest associations with body dissatisfaction. Conclusion. Because BMI was most uniquely predictive of DE in both sexes, adolescents’ awareness of BMI labels (e.g., overweight, obese) may heighten DE. Adolescents generally lack awareness of their BF%, which may be protective in social contexts that narrowly define appearance ideals.

P334

Associations Between Sexual Minority And Intraminority Stressors And Thinness- And Muscularity-Oriented Eating And Body Image Disturbances In Sexual Minoritized Men: Variable-Centered, Person-Centered, And Network Analysis
Wesley Barnhart¹, Kathryn Pasquariello¹, Nathalie Gullo^1,2, Urvashi Dixit³, Rachel Henderson³, Reza Sahlan⁴, Souradeep Chakraborty⁵, Xiaoyin Liu⁶, Cheri Levinson⁷, Jinbo He⁸, Abby Braden⁹
¹Suffolk University, Boston, MA, United States, ²Washington University in St. Louis, St. Louis, MO, United States, ³University of South Alabama, Mobile, AL, United States, ⁴University at Buffalo-State University of New York, Buffalo, NY, United States, ⁵Tata Institute of Social Sciences, Mumbai, India, ⁶Auburn University, Auburn, AL, United States, ⁷University of Louisville, Louisville, KY, United States, ⁸Xi'an Jiaotong-Liverpool University, Suzhou, China, ⁹Bowling Green State University, Bowling Green, OH, United States

Sexual minoritized men (SMM) are at higher risk for eating and body image disturbances than heterosexual men. Sexual minority and intraminority stress may contribute to these health disparities. Research in this area has overwhelmingly applied correlational approaches, precluding understanding of within-group heterogeneity and unique symptom contributions. We applied variable-, person-, and network-centered analyses to investigate the associations between sexual minority and intraminority stress and eating and body image disturbances in SMM. We recruited 255 cisgender SMM (M_age = 25.79) living in the US. Participants self-reported sociodemographic information and completed measures on sexual minority and intraminority stress and eating and body image disturbances. Across each analytic application, sexual minority and intraminority stressors were uniquely associated with higher levels of thinness- and muscularity-oriented eating and body image disturbances. Intraminority body stigma consistently emerged with high salience in these associations. Our findings support the role of sexual minority and intraminority stress in eating and body image disturbances among SMM. Clinicians should consider these risk factors in identifying and treating patients with appearance and eating concerns and explore the role of both distal and proximal stress. Future research can use longitudinal and ecological methods to investigate the temporal directionality of these relationships.

P335

Different Predictive Pathways To Sexual Desire In Women With Eating Disorders: The Role Of Body Trusting And Need For Approval
Eugenia Barone¹, Emanuele Cassioli², Giovanni Castellini², Alessio Maria Monteleone¹
¹Department of Psychiatry, University of Campania "Luigi Vanvitelli", Napoli, Italy, ²Psychiatry Unit, Department of Health Sciences, University of Florence, Firenze, Italy

Introduction: Sexual dysfunction in eating disorders (EDs) shows substantial variability, but the psychological mechanisms underlying this heterogeneity are not well understood. This study examined whether body trusting and need for approval, two key features of ED psychopathology, predict sexual desire differently across subgroups of women with EDs. Methods: A cross-sectional sample of 348 women with anorexia nervosa (AN), bulimia nervosa (BN), or binge-eating disorder (BED) completed measures of sexual functioning (FSFI), interoceptive awareness (MAIA), and attachment (ASQ). Mixture regression was used to identify clusters based on how body trusting and need for approval predicted sexual desire. Multigroup structural equation modeling (SEM) was then applied to test differences in these associations across clusters. Results: Two clusters emerged. In one cluster, both body trusting and need for approval were negatively associated with sexual desire, whereas in the other cluster both showed positive associations. SEM analyses confirmed that these predictive patterns differed between clusters. Conclusions: Women with EDs show distinct patterns in how interoceptive and attachment-related dimensions relate to sexual desire. These findings support the importance of considering individual differences and suggest that targeting interoception and approval-related processes may be relevant for improving sexual well-being in ED populations.

P336

Arfid Traits In A Portuguese Community Sample: Association With Autism Spectrum Traits And Distress Tolerance
Eva Conceição, Célia Ferreira, Dévora Barreira
University of Porto, Faculty of Psychology and Education Sciences, Porto, Portugal

Objectives: This study explored the frequency of ARFID traits in a Portuguese adult community sample and investigated their relationship with potentially associated factors: autistic traits and distress tolerance. Method: A sample of 365 participants responded to an online set of self-report measures disseminated in an academic campus and by snowball procedure in the community, including sociodemographic data, the Nine Item ARFID Scale (NIAS), the Comprehensive Autistic Trait Inventory (CATI), and the Distress Tolerance Scale (DTS). Results: 49(10.1%), 14(2.7%), 37(7.7%) participants scored above the clinical cut-off of the subscales picky eating, fear of negative consequences, and lack of appetite, respectively, and 5(1.4%) scored above the cut-off in all subscales. Multiple linear regression [F(6,359)=7.10,p<.001,R²_adj=.09] investigated which CATI subscales were most associated with NIAS total score, with only sensory sensitivity being significantly associated (b=.19, t=2.82, p=.009). Moderation model tested DTS as a moderator between CATI sensory sensitivity and ARFID total score [F(3,362)=14.35,p<.001,R²=.11]. A significant main effect for CATI sensory sensitivity (b=.66,t=2.68,p=.008), but non-significant main effect for DTS (b=.95, t=.59, p=.56), and non-significant interaction effect (b=-.1,t=-1.41,p=.16) were found. Conclusion: Increased ARFID traits were associated with increased autistic traits, specifically sensory sensitivity, independently of the degree of distress tolerance.

P337

Scrolling For Self-Love: How Body-Positive Content Shapes Body Image In Eating Disorder Populations
Alexandra E. Dingemans^1,2, Jolanda Veldhuis ³
¹GGZ Rivierduinen Eating Disorders Ursula, Leiden, Netherlands, ²Leiden University Medical Center, Leiden, Netherlands, ³Vrije Universiteit, Amsterdam, Netherlands

Introduction: In response to unrealistic, edited appearance-focused content, body positivity has emerged on visual social media, promoting self-acceptance and diverse body representations. However, its impact on individuals with eating disorder (ED) symptoms remains unclear and may depend on social comparison tendencies. This study examined whether body positivity content improved body image among individuals with ED symptomatology. Methods: In an online experiment, 153 adult women with clinical ED symptomatology (Mage = 25.03, SD = 7.89) were randomized to view body positivity (n = 54), thin-ideal (n = 48), or neutral imagery (n = 51). Body appreciation and body dissatisfaction were assessed before and after exposure. Upward appearance-based social comparison and self-esteem were examined as moderators. Results: Body positivity was rated as less beautiful and less thin than thin-ideal, but as more promoting body acceptance (all p’s <.001). A significant condition effect was found for changes in body dissatisfaction (F(2,148) = 4.37, p = .014). Body positivity reduced body dissatisfaction compared to thin-ideal imagery and showed similar effects to neutral imagery). Higher upward social comparison was associated with higher body dissatisfaction, whereas self-esteem showed the opposite pattern (all p’s <.05). No moderation effects were found. Conclusions: Exposure to body positivity content may promote a more positive body image among individuals with eating disorder symptoms.

P338

Self-Reported Versus Objectively Logged Social Media Use: Implications For Measurement In Eating Disorder Research
Scott Griffiths¹, Emma Halliwell¹, Harish Kannan¹, Ben Stone^1,2, Wesley Grey¹, Noa Brittain¹, Eden Shaveet³, Emily Harris¹
¹Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, Australia, ²Unforgettable.Me, Melbourne, Australia, ³Bowers College of Computing and Information Science, Cornell University , New York, NY, United States

Introduction: Self-reported frequency measures of social media use are convenient, yet their criterion validity against objective behavioural data remains largely untested in eating disorder research. We compared self-reports of TikTok use with objective data extracted from TikTok datafiles. Methods: Participants (N = 103) including individuals with diagnosed eating disorders (n = 42) completed a Likert-type self-report measure of TikTok use frequency over the past month. Objective data included the total number of TikTok videos delivered, total number of videos “liked”, number of sessions, and number of “binge scroll” sessions. Associations were tested using Spearman correlations and negative binomial regressions. Results: Self-reports were moderately to strongly correlated with objective indicators: videos delivered (ρ = .55), videos liked (ρ = .59), sessions (ρ = .65), and binge scroll sessions (ρ = .47). Objective use varied substantially within each self-report response category. For example, among participants reporting they “sometimes” used TikTok over the past month, one was delivered 99 videos and another 19,526 videos, representing nearly a 200-fold difference. Conclusions: Self-report frequency measures of social media are meaningfully correlated with objective indicators but compress substantial behavioural variability. Clinicians and researchers should interpret self-reports cautiously, considering objective data whenever possible.

P339

Crossing The Mud: From The (In)-Secure Island To Life &Ndash; A Life-Oriented Therapeutic Framework For Long And Severe Eating Disorders With Chronic Suicidality
Michal Hason Rozestein
Ma'ale HaCarmel mental health center, Haifa region, Israel

Introduction: Women with Severe and Enduring Eating Disorders (SEED) and complex trauma often face chronic suicidality. Symptoms function as an "(In)-secure Island"—a survival defense against traumatic "Mud" (pain). These behaviors provide temporary relief but block access to "Life" (values). Methods: EMDR-SEED is a staged framework integrating: 1) "Island–Mud–Life" mapping; 2) Resource "Raft" building using external anchors; 3) EMDR-inspired processing. Implemented in inpatient SEED groups, the presentation includes case illustrations and the "8-square" protocol. Results: Preliminary case studies show the framework is feasible and well-tolerated. Participants improved resource access and translated distress into life-oriented actions. Currently, findings are limited to clinical case reports. Conclusions: This framework is promising for SEED by framing symptoms as survival attempts. Systematic empirical research is warranted. Keywords: SEED, suicidality, life-oriented, EMDR-inspired, trauma. Learning Objectives: Conceptualize SEED/suicidality within a life-oriented framework. Apply resource mapping to enhance distress tolerance. Demonstrate EMDR-inspired interventions for clinical practice.

P340

Touching Grass: Real-Time Effects Of Nature Exposure On Cognition, Mood, And Body Image
Mariam Huda Mian, Ying Qing Won, Isabel Krug
The University of Melbourne, Melbourne, Australia

Attention Restoration Theory (ART; Kaplan & Kaplan, 1989; Kaplan, 1995) proposes that exposure to natural environments enhances psychological wellbeing by restoring depleted cognitive resources, such as directed attention. Although prior research links nature exposure to improved outcomes, most studies rely on short-term, cross-sectional designs with limited ecological validity and theory-driven testing. This study examined the micro-longitudinal effects of nature exposure and cognitive restoration on mood and body image in daily life. Participants (N = 151; 76.2% women; Mage = 21.1, SD = 5.8) completed a baseline survey followed by smartphone-based Ecological Momentary Assessment (EMA), reporting up to six times daily over one week (max = 42). Measures included recent nature exposure, perceived restoration, happiness, body appreciation, functionality appreciation, and body dissatisfaction. Most participants (96.7%) reported nature exposure. Multilevel analyses showed that momentary nature exposure predicted increases in perceived restoration, happiness, and more positive body image. Perceived restoration also predicted improvements in these outcomes. The association between nature exposure and restoration was moderated by trait connectedness to nature. These findings provide ecologically valid support for ART and highlight nature exposure as a scalable approach to enhancing wellbeing.

P341

Attentional Regulation Inefficiencies In Severe And Enduring Anorexia Nervosa: Implications For Strategic Control
Louise Karjalainen, Urban Norén, Elisabet Wentz
Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden

Introduction Severe and enduring anorexia nervosa (SE-AN) is characterized by persistent impairment and limited treatment response. Altered attentional and executive control may contribute to illness persistence. Methods Seventy-five adults with SE-AN and SE-atypical anorexia nervosa (AN) from two specialized eating disorder units in Gothenburg, Sweden (mean age 32.3 [18–79]; mean AN duration 13.5 years [3–40]; mean BMI 18.5 kg/m² [13.4–25.4]) completed Cambridge Neuropsychological Test Automated Battery (CANTAB) tests of sustained attention, working-memory strategy, planning, and visual memory. Regression tested whether sustained attention predicted working-memory strategy after controlling for clinical variables. Results A selective neurocognitive profile emerged. Sustained attention was reduced and working-memory strategy impaired, while planning and visual memory were preserved. Sustained attention predicted working-memory strategy after controlling for clinical variables (β = .300, p = .016). Cognitive performance was unrelated to clinical measures (e.g. BMI, AN duration, age). Conclusions Findings indicate selective inefficiency in attentional and strategic control rather than global impairment. Sustained attention was associated with working-memory strategy independent of clinical factors, highlighting a link between attentional regulation and strategic control. These alterations may contribute to illness persistence by increasing cognitive demands during behavioural change.

P342

Inspiration Or Instigation? Bidirectional Links Between Body-Focused Content, Body Image, And Disordered Eating Urges
Wenn Lynn Ooi, Julian Simmons, Isabel Krug
The University of Melbourne, Melbourne, Australia

Using ecological momentary assessment (EMA), this study examined bidirectional associations between exposure to body-focused inspiration content (thinspiration, fitspiration, fatspiration) and body image and disordered eating (DE) urges, as well as gender differences. Undergraduate students (n = 858; 78.3% women) reported six times daily over seven days on content exposure, body dissatisfaction (BD), body objectification (BO), body appreciation (BA), and urges to restrict food intake and exercise. Multilevel analyses showed that viewing thinspiration predicted higher BD, fitspiration predicted lower BA, and fatspiration predicted stronger urges to exercise. In the reverse direction, only one association emerged: higher BO predicted less thinspiration viewing. Gender did not moderate these momentary relationships. Overall, findings suggest limited and non-uniform bidirectional effects between content exposure and body- and eating-related outcomes. Encouraging individuals to actively manage social media use may help reduce potential harm. Future research should examine other moderators, such as internalised health and weight attitudes, and consider whether gender differences emerge beyond momentary effects, including cumulative exposure and broader self-evaluations.

P343

The Relationship Between Stress And Eating-Disorder Symptoms In Anorexia Nervosa: A Qualitative Investigation
Robin Quagebeur^1,2, Emma De Schuyteneer^1,2, Elske Vrieze^1,2
¹1Mind-Body Research, Biomedical Sciences Group, KU Leuven, Leuven, Belgium, ²2Leuven Brain Institute, KU Leuven, Leuven, Belgium

Objectives: To gain an interpretative understanding of the bidirectional relationship between momentary stress and eating-disorder-related symptoms in anorexia nervosa (AN). Methods: Semi-structured, in-person interviews were conducted with 17 inpatients with AN admitted to the University Psychiatric Centre KU Leuven, Belgium. The sample included 16 females and 1 male, with a mean age of 28.8 years (SD = 12.9; range 17–60) and a mean BMI of 14.6 kg/m² (SD = 2.2; range 11.4–18.5). Data were analysed using inductive reflexive thematic analysis. Results: Preliminary analysis suggests that participants described stress and eating-disorder symptoms as deeply intertwined in everyday life. While the sources of stress appeared highly individual, participants seemed to describe similar ways in which stress became translated into eating-disorder-related behaviours. At the same time, these behaviours were experienced not only as responses to stress, but also as processes that could maintain, reinforce, or reshape subsequent stress. Taken together, early findings point to a dynamic and bidirectional relationship between stress and eating-disorder symptomatology in AN. Conclusions: These preliminary findings suggest that the relationship between stress and eating-disorder symptoms in AN is not linear, but reciprocal and self-perpetuating. A qualitative interpretative approach may help to better understand how personally meaningful stressors become expressed through shared behavioural patterns.

P344

Social Media And Body Image Among Young Autistic Individuals
Rachel F Rodgers^1,2,3, Isabel Cunha¹, Veronica Rubinsztain⁴, Xinran Wang¹, Meryl Alper⁴
¹APPEAR, Northeastern University, Boston, MA, United States, ²Universite Lapeyronie, Montpellier, France, ³Unité de Recherche Clinique & Innovation, Hopital du Cotentin, Cherbourg, France, ⁴Department of Communication Studies, Northeastern University, Boston, MA, United States

Objective: Social media exposure is associated with poor body image and eating outcomes in young people. Autistic individuals may be more vulnerable to this exposure, and experience frequent eating disorders with unique presentations. This study investigated how autistic individuals experience social media content pertaining to food and disordered eating through quantitative (study 1) and qualitative (study 2) designs. Methods: Study 1 included young autistic women and non-binary individuals assigned female at birth (n = 40, Mage = 21.28, 75.7% White) randomly assigned to view 3 TikTok videos depicting (a) flexible eating habits and positive body image, (b) disordered eating, or (c) both. In study 2, n = 20 participants (Mage = 22.80, 70% White) were interviewed. Results: In study 1, differences emerged for urges to restrict and shape and weight satisfaction, with the ED condition reporting the worst outcomes. No effects existed for the other mood, body image, and eating state outcomes. State appearance comparison mediated the relationship with shape and weight satisfaction, but not urges to restrict. In study 2, thematic analysis revealed greater engagement with social media among those who struggled with body image and eating. Some described helpful active and critical participation online. Conclusions: Social media exposure may have short-term positive or negative implications for body image and eating among autistic individuals. Additional work is needed this vulnerable and overlooked group

P345

Longitudinal Relationships Between Systemic Gender Minority Stressors And Eating Pathology Among Transgender And Gender Diverse Adults
Kira G. Venables, Bek Urban
Virginia Commonwealth University, Richmond, VA, United States

Introduction: Eating disorders disproportionately impact transgender and gender diverse (TGD) individuals. Cross-sectional data indicate that contextual factors, such as gender minority stress, are associated with more severe eating pathology. However, little is known about how more systemic facets of gender minority stress may impact disordered eating over time among TGD adults. Methods: TGD adults (N=166) recruited via Prolific completed measures of vicarious gender minority stress, body/gender policing, gender-related vigilance, perceptions of safety, and the Eating Disorder Examination Questionnaire (EDE-Q) at baseline and one-month follow-up. Multiple regression models tested whether gender minority stressors predicted EDE-Q global scores cross-sectionally and longitudinally, controlling for age and baseline symptoms. Results: Cross-sectionally, greater gender-related vigilance predicted more severe eating disorder symptoms (β=.57, p<.001). Longitudinally, greater body/gender policing predicted more severe eating disorder symptoms (β=.15, p<.001). Conclusions: Systemic minority stress factors may impact eating pathology among TGD adults both cross-sectionally and longitudinally, though associations differ based on timepoint. Assessment of gender minority stress is important for researchers and clinicians to understand eating pathology in TGD populations. Future research should examine specific mechanisms linking these stressors to disordered eating across longer follow-up periods.

P346

Unravelling Causal Relations In Eating Disorder Symptom Networks Of People With Anorexia Nervosa
Eva P. Wuttke^1,2,3, Adrian Meule^3,4, Erich Kummerfeld⁵, Lisa M. Anderson⁵, Ulrich Voderholzer^1,2,6, David R. Kolar³
¹Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Munich, Germany, ²Schoen Clinic Roseneck, Prien am Chiemsee, Germany, ³Department of Psychology, University of Regensburg, Regensburg, Germany, ⁴Department of Medicine, HMU Health and Medical University, Düsseldorf, Germany, ⁵Department of Psychiatry and Behavioral Science, University of Minnesota Medical School,, Minneapolis, MN, United States, ⁶Department of Psychiatry and Psychotherapy, University Hospital of Freiburg, Freiburg, Germany

Introduction: Previous symptom network studies on anorexia nervosa (AN) have identified strong associations among core eating disorder symptoms, such as desiring weight loss, dietary restraint, preoccupation with shape and weight, shape overevaluation, and fearing weight gain. However, these models rely on undirected associations and do not allow conclusions about potential causal relationships among symptoms. This study investigates the causal structure of eating disorder symptoms in persons with AN. Methods: Item-level Eating Disorder Examination–Questionnaire data from a large inpatient sample of approximately 1,500 persons with AN treated at the Schoen Clinic Roseneck (Germany) are analyzed using causal discovery methods. Literature-informed and purely data-driven models are compared. Models are estimated on training data, evaluated on held-out test data, and stability is assessed via bootstrapping. The study is preregistered (https://osf.io/29ne8) and all data have been collected. Results: Analyses are currently ongoing. We will present a comparison of literature-informed and data-driven directed causal models, including their stability and predictive generalizability. Conclusions: By moving beyond undirected symptom networks, this study evaluates whether previously reported network structures align with plausible causal models. Identifying directional relationships among symptoms may inform a more mechanistic understanding of AN and support symptom-focused interventions.

P347

Experiences Of Patients Receiving Concurrent Anorexia Nervosa And Post-Traumatic Stress Disorder Treatment
Ella van Beers¹, Lot Sternheim², Margo de Jonge¹
¹Novarum Centre for Eating Disorders, Amstelveen, Netherlands, ²Utrecht University, Utrecht, Netherlands

PTSD is a risk factor for treatment dropout and relapse in anorexia nervosa (AN), yet no evidence-based treatments exist to support this comorbidity. Pilot studies on preliminary efficacy are emerging, yet the experiences of patients in these trials is largely unknown. This study aimed to capture patients’ perspectives receiving combined AN-PTSD treatment. Method: Individual semi-structured interviews were conducted with eight adults receiving combined AN-PTSD treatment. Interviews examined participants’ (1) motivation for receiving combined treatment, (2) experiences during treatment, and (3) the logistics of combined treatment. Interviews were transcribed verbatim and analyses were conducted using thematic analysis in MAXQDA. Results: Five themes emerged: (1) burden of combined treatment, (2) value of combined treatment, (3) AN-PTSD relationship, (4) caregiver support, and (5) mediators of engagement. Most participants described a heavy cognitive load while also benefitting from fewer PTSD symptoms. Some described a cycle of restriction triggering nightmares and flashbacks, while others described flashbacks as triggering restriction and poor body image. Avoidance was a barrier to engagement and the need for support outside of sessions were emphasized. Conclusions: Symptom stabilisation for one disorder may depend on treatment of the other. Combined treatment was very intensive and beneficial in reducing PTSD symptoms. Combined approaches should be investigated using patient feedback.

P348

An Online Guided Self-Help For Transdiagnostic Eating Disorders: The Results Of The Interconnect-Ed Trial
Gaia Albano¹, Salvatore Gullo¹, Cristina Segura-Garcia ², Valentina Cardi³, Mariarita Semola¹, Vittoria Franchina¹, Gianluca Lo Coco¹
¹Department of Psychology, Educational Science and Human Movement, University of Palermo, Palermo, Italy, ²Outpatient Unit for Clinical Research and Treatment of Eating Disorders, University HosDepartment of Medical and Surgical Sciences, University “Magna Graecia” , Catanzaro, Italy, ³Department of General Psychology, University of Padova, Padova, Italy

Introduction: Digital guided self-help interventions may improve outcomes in eating disorders although further research is needed to ascertain their effectiveness across different settings. This study examined the feasibility of an 8-week mobile app self-help intervention (INTERconNEcT-EDs) in outpatient and community samples. Methods: Two randomized controlled trials (RCT) were conducted: in the first RCT, 122 outpatients were randomized to treatment as usual (TAU; n=56) or TAU plus self-help (n=66). In the second RCT, 60 participants with disordered eating were assigned to a wait-list condition (n=27) or self-help intervention (n=33). Treatment effects were analyzed through generalized linear models. Results: At end of treatment, significant improvement in psychological distress (primary outcome) and eating disorder symptomatology (secondary outcome) was evident in both samples over time. In the community group, significant time-by-group interactions indicated greater improvements in the intervention group for the EDE-Q Eating Concern scale (p=.009) and for 2 domains of the CORE-OM (functioning p=.013, and wellbeing p=.023). However, no significant time x group interaction effect emerged for the outpatients. At 3-month follow-up the results remained consistent for the community sample. Conclusions: The INTERconNEcT-EDs program appears to be a viable option across various stages of illness, with encouraging outcomes observed in non-clinical populations and specific domains.

P349

Using Ecological Momentary Assessment To Inform Micro‑Interventions For Reducing Eating Disorder Risk: Findings From Two Feasibility Studies
Melissa J Atkinson, Amy Robbins, Lucy Tipple
University of Bath, Bath, United Kingdom

Adolescence and early adulthood are critical periods for eating disorders (ED). We explored Ecological Momentary Assessment (EMA) across two studies to gain insight of dynamic risk processes to inform preventive micro-interventions. Study 1 recruited young adults to a pilot trial of a 15‑minute digital mindfulness‑based micro‑intervention (N = 31; M_age = 28.0), who completed EMA surveys four times daily over 7 days to assess mindfulness practice, state mindfulness, mood, and weight/shape satisfaction. Study 2 implemented a refined EMA protocol using a different platform in a non‑clinical adolescent sample (N = 50; M_age= 17.4 years). Adolescents completed surveys three times daily for 7 days assessing momentary ED risk, protective states, and appearance‑related triggers. Feasibility, acceptability, and within‑person associations were examined using mixed‑methods and multilevel modelling. EMA acceptability was positive across studies, including increased self‑awareness and low burden. Feasibility improved, with higher compliance (82.5%) following protocol refinement. Higher momentary protective states—particularly mindfulness—were associated with lower concurrent ED risk and more positive affect. In adolescents, appearance‑related triggers were linked with elevated momentary risk. Findings demonstrate the importance of EMA design and support further evaluation of mindfulness‑related states as momentary protective factors in the context of ED prevention.

P350

Establishing Academic And Community Partnerships To Improve Outcomes For Post-Secondary Students With Eating Disorders In Canada
Lindsay Bodell¹, Cheryl Forchuk^1,2, Anne Peters², Jonathan Serrato², Avery Bender¹, Robbie Campbell^{3, 4}
¹Western University, London, ON, Canada, ²Lawson Research Institute, London, ON, Canada, ³Eating Disorders Foundation of Canada, London, ON, Canada, ⁴The Harbour , London, ON, Canada

Post-secondary students represent one group at particularly high risk for eating disorders, with up to 40% experiencing clinically significant eating disorder behaviors and approximately 13% developing a diagnosable eating disorder. Despite the high prevalence of eating disorders in this population, Canadian university health systems are not set up to readily identify and treat eating disorders, and established care models rarely consider the unique environment and needs of post-secondary students. The Harbour Eating Disorders Program was developed in 2024 to provide accessible outpatient eating disorders treatment for university students in London, Ontario. The program uses a multidisciplinary and student-centered approach to support students’ quality of life and academic success. Although operational, the effectiveness of The Harbour’s treatment approach remains unknown. We have developed a research advisory board that includes academic researchers and representatives from student health services, the Harbour treatment team, the Eating Disorder Foundation of Canada (non-profit), and students with lived experience of an eating disorder. Together, our team has designed a mixed-methods research study to evaluate patient experiences and clinical outcomes. This presentation will discuss the formation of our research advisory board and co-designed study, and we will present preliminary data from qualitative interviews with patients at the Harbour (expected N=10).

P351

Development Of A Modular Intervention For Children & Adolescents Living With Avoidant Restrictive Food Intake Disorder: A Systematic Process
Rachel Bryant-Waugh^1,2, Leanne Dreyer^2,3, Sophie Bennett^1,2
¹South London and Maudsley NHS Foundation Trust , London, United Kingdom, ²Kings College London , London, United Kingdom, ³Guys and St Thomas' NHS Foundation Trust , London, United Kingdom

Introduction: Avoidant restrictive food intake disorder (ARFID) is characterised by restricted or avoidant eating leading to nutritional, medical &/or psychosocial impairment. Heterogeneous presentations highlight the need for flexible, scalable interventions. Methods: A novel multi-step process introduced by Davey et al., 2024 is being used to develop a modular intervention for young people with ARFID, informed by the 3 pillars of evidence-based practice (research, clinician expertise, patient preference). Pillar 1 involves a systematic review & common elements analysis to identify shared, adaptable intervention components, with strategies coded into discrete elements. Pillar 2 comprises interviews & focus groups with multidisciplinary clinicians from 2 specialist services to identify key components, delivery formats & implementation considerations. Pillar 3 captures patient perspectives through interviews & focus groups with young people with ARFID & their caregivers. Findings will be integrated using a coding matrix to inform the modular framework, with member checking by clinicians, parents & young people. Iterative cycles will refine & assess feasibility. Results: Early synthesis highlights convergence across behavioural, cognitive & parent-mediated strategies, supporting a personalised, modular framework. Conclusions: This work aims to standardise & manualise ARFID care through a modular intervention grounded in empirical evidence, lived experience, & clinical expertise.

P352

Virtual Reality CafÉ Intervention Alongside Usual Care For People With Eating Disorders: A Mixed-Methods Single Arm Feasibility Study
Laura Chapman^1,2, Lucy Biddle^1,2, Peter Blair⁴, Gillian Combe⁵, James Downs⁶, Alys Grant⁷, Robert Mullen³, Anne Stewart⁸, Ian Penton-Voak^2,9, Lucy Yardley^9,10, Bernhard Spanlang¹¹, Paul Moran^1,12, Tamsin Ford¹³, Helen Bould^1,2,3
¹Centre for Academic Mental Health, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom, ²NIHR Bristol Biomedical Research Centre, University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, UK, Bristol, United Kingdom, ³Gloucestershire Health and Care NHS Foundation Trust, Gloucester, United Kingdom, ⁴Population Health Sciences, Bristol Medical School, University of Bristol , Bristol, United Kingdom, ⁵Oxford Health NHS Foundation Trust, Oxford, United Kingdom, ⁶Expert By Experience, Cardiff, United Kingdom, ⁷Expert By Experience, Canterbury, United Kingdom, ⁸Department of Psychiatry, University of Oxford, Oxford, United Kingdom, ⁹School of Psychological Science, University of Bristol, Bristol, United Kingdom, ¹⁰School of Psychology, University of Southampton, Southampton, United Kingdom, ¹¹Kiin , Barcelona, Spain, ¹²Avon and Wiltshire Mental Health Partnership NHS Trust, Bristol, United Kingdom, ¹³Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom

Introduction. New treatments for eating disorders (ED) are needed, including those that address the social impairment many people with ED describe. Virtual Reality (VR) offers opportunities to improve treatment accessibility, and there is evidence it may be beneficial in treating ED. Using the Person-based Approach, we have co-developed a VR café intervention where people with ED can practice challenges related to social eating. Methods. This is a mixed-methods single arm feasibility study with a 3-month follow-up, designed to find out whether it is feasible to recruit, retain and follow-up people to receive the VR café intervention in a clinical setting. 30 young people across two NHS trusts will receive clinician-supported sessions using the intervention, in addition to their usual ED treatment. We will measure feasibility and participant-centred outcomes, VR engagement data, and participant service use data. A nested qualitative study will offer further insights into feasibility and acceptability. Results. The trial was registered on the ISRCTN registry on 23^rd April 2026 (ISRCTN37191564) and will run until October 2027. Conclusions. Our co-designed VR café intervention is designed to act as a stepping stone to engaging in social eating situations in real life, by enabling people with ED to practice skills in a controlled, supported environment, to reduce anxiety and increase self-efficacy. Our aim is that the findings will inform a randomised controlled pilot trial.

P353

Implementation Of A Training Hub To Build Capacity For Pediatric Eating Disorders Services
Jennifer S Coelho^1,2,3, Julia Kaufmann^2,3, Sharon HJ Hou^2,4, Tayla Bain², Patricia Obee², Josie Geller^3,5, Kim Williams¹, Jeffrey N Bone^2,3, Jennifer Couturier^6,7, Melissa Kimber^6,7, Sarah Hooseman², Heidi Grogan⁸, Nicole Obeid^9,10, Brynn Kelly¹¹, Daniel Le Grange^12,13, Gina Dimitropoulos¹⁴
¹BC Children's Hospital, Vancouver, BC, Canada, ²BC Children's Hospital Research Institute, Vancouver, BC, Canada, ³University of British Columbia, Vancouver, BC, Canada, ⁴Simon Fraser University, Burnaby, BC, Canada, ⁵St. Paul's Hospital, Vancouver, BC, Canada, ⁶McMaster University, Hamilton, ON, Canada, ⁷McMaster Children's Hospital, Hamilton, ON, Canada, ⁸Lived Experience Partner, Calgary, AB, Canada, ⁹Children's Hospital of Easter Ontario (CHEO) Research Institute, Ottawa, ON, Canada, ¹⁰University of Ottawa, Ottawa, ON, Canada, ¹¹Dalhousie University, Halifax, NS, Canada, ¹²University of California, San Francisco, CA, United States, ¹³University of Chicago, Chicago, IL, United States, ¹⁴University of Calgary, Calgary, AB, Canada

Background: As part of a capacity building initiative for pediatric eating disorders, we developed a Provincial Eating Disorders Training Hub. Clinicians working in the public pediatric healthcare sector in British Columbia and the Yukon, Canada can access training and consultation through the Training Hub, with an initial focus on family-based treatment (FBT). We are evaluating the Training Hub as an implementation strategy, using the PRISM and RE-AIM for Sustainability framework. We also assess professional well-being and turnover intention in clinicians who access Training Hub supports. Methods: Implementation data was collected to assess engagement with the Training Hub. Participants completed measures of professional well-being, turnover intention, FBT confidence, and use of FBT at baseline, pre- and post-training, and at 3-month follow-up. Results: A total of 328 clinicians have expressed interest in Training Hub supports. Of these, 214 have engaged with the Training Hub over 9 cohorts, and 178 have participated in research. We will report implementation outcomes using the RE-AIM framework. Data from the final cohort has recently been collected, and evaluation outcomes will be analyzed using mixed effects models to account for repeated measures. Conclusions: We anticipate that access to training and consultation supports will be associated with higher clinician professional well-being, as well as improve the accessibility of evidence-based treatments for pediatric eating disorders.

P354

Parent- And Patient-Rated Internalizing Symptoms As Predictors Of Treatment Acceptability And Attrition In Adolescent Eating Disorders
Sarah Dolan¹, Sarah Eckhardt², Daniel Le Grange¹, Carolyn Martell², Erin Reilly¹, Sasha Gorrell¹
¹University of California, San Francisco, San Francisco, CA, United States, ²Children's Minnesota, St. Paul, MN, United States

Introduction: Internalizing psychopathology (e.g., depression, anxiety) is common among youth with eating disorders (EDs) and associated with worse clinical outcomes, though less is known about how these symptoms impact treatment engagement. We examined how parent-rated internalizing symptoms and patient-rated depression relate to attrition and acceptability in youth who participated in a nonrandomized trial of enhanced cognitive behavioral therapy (CBT-E) or family-based treatment (FBT). Methods: Pre-treatment, 97 adolescents with EDs completed the Children’s Depression Inventory (CDI) and parents completed the Child Behavior Checklist (CBCL). Patients provided biweekly ratings of perceived suitability and success of treatment. Results: Multilevel models indicated that baseline CBCL internalizing scores predicted lower suitability, b=−.06, p=.03, and success, b=−.07, p=.02, ratings. Patient-rated depression, treatment type, weight status, and age were not associated with either rating score. Neither CDI nor CBCL scores predicted attrition. Conclusions: Greater parent-rated internalizing symptoms but not patient-rated depression were associated with lower patient ratings of treatment acceptability, highlighting the utility of caregiver reports in identifying youth who may benefit from early efforts to increase engagement. Notably, internalizing symptoms were not associated with attrition, which suggests internalizing symptoms may more strongly relate to lower engagement than dropout.

P355

Investigating The Mechanisms Underlying The Effects Of Semaglutide On Binge Eating In Obesity: A Protocol
Annelies Falter^1,2, Alexine Mennes^2,3, Lukas Van Oudenhove³, Weltens Nathalie³, Van der Schueren Bart², Van Goitsenhoven Roman ², Vrieze Elske¹
¹KU Leuven, Dept. of Neurosciences, Research unit Mind-Body Research (MBR), Leuven, Belgium, ²KU Leuven, Dept. of Chronic Diseases and Metabolism (CHROMETA), Research unit Clinical and Experimental Endocrinology (CEE), Leuven, Belgium, ³KU Leuven, Dept. of Chronic Diseases and Metabolism (CHROMETA), Research unit Translational Research in GastroIntestinal Disorders (TARGID), Leuven, Belgium

Introduction: GLP-1 receptor agonists (GLP-1RA) have transformed obesity treatment, yet substantial inter-individual variability in treatment response remains. Eating behaviour, shaped by interacting homeostatic, reward-related and emotional processes, is increasingly considered a key candidate explaining this variability. GLP-1RA are also receiving attention as a treatment for maladaptive eating behaviours, particularly binge eating (BE), which is often underdiagnosed in obesity. However, how GLP-1RA affect eating behaviour remains unclear. Methods: This study will include 96 individuals with obesity, stratified by BE severity. Participants will receive semaglutide (GLP-1RA) for 6 months and undergo assessments at baseline, 3 and 6 months, including anthropometric measures and multimodal assessment of eating behaviour and its underlying homeostatic, reward-related and emotional processes. These will be assessed using the experience sampling method (ESM), questionnaires, food diaries, measures of dopamine and metabolic hormone levels and neuroimaging (fMRI and PET). Results: Recruitment is expected to start in July 2026. We will examine changes in BE severity and anthropometric outcomes and assess how semaglutide affects eating behaviour and its three underlying motivational psychobiological processes. Conclusions: This study aims to investigate the effects of semaglutide to better understand variability in treatment response and improve personalized patient selection for GLP-1 based therapies.

P356

Ketogenic Diet Therapy In Bulimia Nervosa &Ndash; A Case Report
Guido K.W. Frank, Emma Longmire, Megan E. Shott
University of California San Diego, San Diego, CA, United States

Objectives: Bulimia nervosa (BN) is a severe psychiatric disorder characterized by often unsatisfactory treatment outcomes and high relapse rates. Research suggests that metabolic processes may play a role in the pathophysiology of eating disorders. Ketogenic diet therapy (KDT), a dietary intervention that relies primarily on fat as energy source, has shown promise in the treatment of anorexia nervosa, prompting its investigation in BN. Methods: We report the case of a 43-year-old woman with a 31-year history of BN, characterized by on average three weekly binge-eating episodes followed by compensatory self-induced vomiting. The patient underwent a 14-week KDT intervention, with monitoring of ketone levels and body weight. Results: At baseline, the patient presented with a body mass index (BMI) of 37, highly elevated eating disorder, impairment and depressive symptom scores, including a history of 4.5 years of electroconvulsive therapy (ECT) for treatment-resistant depression.At study completion, she demonstrated a marked reduction in eating disorder psychopathology (Eating Disorder Examination Questionnaire [EDE-Q] Global score: 5.3 to 3.3; Eating Disorder Inventory-3 Bulimia subscale: 13 to 9), and depressive symptoms (Beck Depression Inventory [BDI]: 38 to 12), while BMI did not change. Conclusions: This case suggests that KDT is a feasible and well-tolerated intervention for BN and may be associated with meaningful reductions in both eating disorder and depressive symptoms.

P357

Should Eating Disorder Treatments Be Personalized? Estimating Heterogeneity Of Treatment Effects In A Variance-Ratio Meta-Analysis Of Randomized Controlled Trials
Yaroslava Gelbert¹, Philipp Herzog², Tim Kaiser³, Marco Solmi⁴, Alessio Maria Monteleone⁵, David R. Kolar¹
¹Department of Psychology, University of Regensburg, Regensburg, Germany, ²Department of Psychology, RPTU University Kaiserslautern-Landau, Landau, Germany, ³Department for Methods and Evaluation/Quality Assurance, Institute for Educational Sciences and Psychology, Freie Universität Berlin, Berlin, Germany, ⁴Department of Psychiatry, University of Ottawa, Ottawa, ON, Canada, ⁵Department of Psychiatry, University of Campania “Luigi Vanvitelli”, Naples, Italy

Psychological treatments for eating disorders (ED) remain insufficiently effective, with high rates of non-response and relapse. Personalizing psychological treatments has been proposed to improve outcomes. However, this is only justified if treatment effects meaningfully differ across patients. Whether heterogeneity of treatment effects (HTE) exists in psychological treatments for EDs remains unclear. We estimated HTE with data from 37 RCTs (41 intervention arms; N = 2555) evaluating psychological treatments for anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), and at-risk samples. We conducted a Bayesian variance‑ratio meta‑analysis to quantify variability in treatment effects across patients for body mass index (BMI), EDE-Q global score, and EDE global score. Across diagnoses and outcomes, HTE was generally small and associated with uncertainty. However, probability-of-direction analyses revealed systematic patterns not captured by variance-ratios alone. BN showed consistent posterior support for increased variability across outcomes, most notably for EDE-Q (Pd = 0.94), followed by AN. BED showed little evidence for increased variability, and at-risk samples showed strong support for reduced variability. Results suggest that personalization of existing ED treatments may be more limited than often assumed. Personalization may be most promising for BN, while generalized treatments may already be well suited for BED and at-risk populations.

P358

Toward Ecological Validity In Virtual Reality Food Cue Exposure: Cultural Adaptation And Evaluation In A Brazilian Context
Walter Gonçalves¹, Carla Mourilhe¹, Carlos de Moraes¹, Rafael Garcia², Lucio Lage², Antônio Nardi², Cristin Runfola³, Debra Safer³, Phillipa Hay^4,5, Luca Bernardelli⁶, Giuseppe Riva⁷, José Carlos Appolinario^1,2
¹Obesity and Eating Disorders Group, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, ²Virtual Reality Laboratory, Institute of Psychiatry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, ³Department of Psychiatry & Behavioral Sciences, Stanford University, School of Medicine, Stanford, CA, United States, ⁴Translational Health Research Institute, School of Medicine, Western Sydney University, New South Wales, Australia, ⁵Mental Health Services, South Western Sydney Local Health District, Camden and Campbelltown Hospital, Campbelltown, Australia, ⁶Facoltà di Psicologia, Università Cattolica del Sacro Cuore, Milano, Italy, ⁷Humane Technology Lab, Università Cattolica del Sacro Cuore, Milano, Italy

Introduction: Cultural adaptation of Virtual Reality (VR) food cue exposure systems is essential for ecological validity and clinical applicability. This study aimed to adapt a VR Food Cue Exposure system to the Brazilian context and examine comprehensibility, usability, and realism. Methods: Thirty Brazilian food items were integrated into a VR system originally developed for the Italian context. Participants included 17 healthcare professionals without eating disorders and 16 individuals with Binge-Eating Disorder (n=8) or Bulimia Nervosa (n=8). After immersion, participants completed a questionnaire assessing realism, cultural adequacy, pleasantness, eating desire, presence, and side effects. Data were analyzed using the Top-2-Box approach and group comparisons using nonparametric and categorical tests. Results: The VR environment was rated as highly immersive by both groups (100%). High realism (94–100%), cultural adequacy (93–94%), and pleasantness (93–94%) were observed, with no between-group differences. Food realism (73–82%) and eating desire (60–76%) were comparable. Anxiety differed: patients reported neutral anxiety (60%), while professionals reported no anxiety (70.6%) (p=0.009). Technical difficulties occurred only in professionals (45%; p=0.004). Side effects were minimal. Conclusion: The adapted VR system showed high acceptability, usability, and safety, supporting its use as a culturally sensitive tool for food cue exposure in binge-eating spectrum disorders.

P359

Blurring The Boundaries: An Investigation Of Eating Disorder Recovery Content On Tiktok
Scott Griffiths¹, Isabel Martyn¹, Harish Kannan¹, Ben Stone^1,2, Emma Austen¹, Edoardo Tescari³, Usha Nattala³, Wesley Grey¹, Noa Brittain¹, Deborah Mitchison⁴, Jake Linardon⁵, Jasmine Fardouly⁶, Emily Harris¹
¹Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, Australia, ²Unforgettable.Me, Melbourne, Australia, ³Melbourne Data Analytics Platform, University of Melbourne, Melbourne, Australia, ⁴Discipline of Psychology, University of Technology Sydney, Melbourne, Australia, ⁵School of Psychology, Deakin University, Melbourne, Australia, ⁶School of Psychology, University of Sydney, Melbourne, Australia

Objective. Eating disorder recovery content is widely circulated on social media. This mixed-methods study thematically analysed recovery content on TikTok, examined its association with symptom severity among individuals with eating disorders, and assessed its co-occurrence with pro-eating disorder material within users’ feeds. Method. We analysed TikTok usage data from 42 individuals with clinically diagnosed eating disorders over a one-month period and thematically analysed 250 TikTok posts containing eating disorder recovery hashtags. Results. Fifty percent of “recovery” posts contained pro-eating disorder elements, including messaging consistent with disordered eating norms and thin-ideal reinforcement. Quantitative analyses provided no evidence that greater exposure to recovery content was associated with lower symptom severity. Recovery and pro-eating disorder content were strongly correlated within participants’ TikTok feeds in terms of both the volume of videos delivered (Spearman’s ρ = .91) and their proportional representation (ρ = .77). Discussion. TikTok content pitched as “eating disorder recovery” often contains pro-eating disorder features, shows no protective association with symptom severity, and is encountered alongside genuine pro-eating disorder content within users’ feeds. We conclude that overlap between recovery content and pro-eating disorder content operates at two levels: within individual videos and across the broader feed context.

P360

The Family-Based Telehealth Vs. Institutional Anorexia Nervosa Therapy (Fiat) Study: Aims, Methodology, Challenges And Current Status
Verena K Haas¹, Stefan Ehrlich², Ulrich Voderholzer³, Viktor Nöhles¹, Daniel Le Grange⁴, Christoph U. Correll¹
¹Charité-Universitätsmedizin, Berlin, Germany, ²Carl Gustav Carus Universitätsklinikum, Dresden, Germany, ³Department Psychiatry and Psychotherapy, University Hospital Munich, Munich, Germany, ⁴University of California, San Francisco , CA, United States

Background: The Family-Based telehealth vs. Institutional Anorexia Nervosa-Therapy (FIAT) study compares for the first time FBT with inpatient multimodal therapy (IMT) in youth with anorexia nervosa (AN) with indication for inpatient care. Methods: At 22 clinics in Germany, 200 publicly insured youth (8-17 years) with AN will be randomized into in this non-inferiority trial that started in 07/2025. FBT is implemented as a stepped-care model, with stepwise treatment intensification, or ultimately transfer to naturalistic IMT, if progress is insufficient. Medical supervision of the FBT group is provided in person at the respective study center. Primary endpoint: Change in percentage median body mass index between baseline and 12 months, with additional assessments at end of treatment and 6 months. Secondary endpoints: AN-specific psychopathology, urge for movement, depressive symptoms, adverse effects, menstrual status (girls), medications, motivation for change, quality of life, emotional and financial burden on caregivers, treatment satisfaction, family functioning, and treatment costs. Results: At all study centers, two FBT therapists as well as additional study personnel (physicians and assessors) were trained to conduct the FIAT study. Initial recruitment difficulties had to be identified and addressed. Currently, 83 families have been randomized. Conclusion: Randomization of severely ill youth with AN into two very different treatment settings is challenging but possible.

P361

Specialized, Integrative Treatment For Long-Standing Eating Disorders: Early Insights And Implications
Nuria Jaurrieta¹, Rosa Fontana^{1, 2}, Gara Alias^{1, 2}, Karla Fernández de Betoño^{1, 2}, Carlos Ruiz-García¹, Alberto García-Ruiz¹, Alexandra Ruiz-Pradas¹, Blanca Ferrer-Bomsons¹, Laia Merida⁴, Anna Esteve-Gibert¹, Nuria Vendrell⁴, Jose Lechuga⁴, Santi Bernades⁴, Carlos Franquelo⁴, Stephen Touyz⁵, Fernando Fernandez-Aranda^{1, 2, 3}
¹Long-standing ED Unit, Fundación Hospitalarias Martorell, Barcelona, Spain, ²Clinical Psychology Department, Bellvitge University Hospital-IDIBELL and CIBERobn, , Barcelona, Spain, ³Department of Clinical Sciences, School of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain, ⁴Fundacion Hospitalarias Martorell, Barcelona, Spain, ⁵Inside In Inside Out Institute, Sydney, Australia

Despite advancements in treatment modalities, a substantial gap persists in evidence based interventions specifically designed for individuals with enduring EDs. Objective: A specialized residential unit dedicated exclusively to the care of adults with long-standing EDs was launched within the Catalan Public Health System in January 2024. This study introduces the unit’s innovative therapeutic model and presents preliminary outcomes related to patient satisfaction, BMI, and quality of life. Method: This preliminary investigation included 18 participants diagnosed with anorexia nervosa (AN) or other specified feeding or eating disorders (OSFED/AN), according to DSM-5 criteria. Each participant underwent a structured 2 clinical interview and completed a comprehensive battery of quantitative and qualitative assessments with the treatment received over an average stay of 3–4 months. Results: Participants had a mean illness duration exceeding 12 years and had previously undergone at least three unsuccessful full-treatment attempts. Post-treatment analyses revealed significant improvements in quality of life (p<.001) and BMI (p<.001). The mean satisfaction score was 85.3 out of 100, aligning with the positive qualitative feedback provided by participants. Discussion: Preliminary findings suggest that this novel residential approach yields meaningful improvements in quality of life and psychopathological symptoms, while fostering greater autonomy among individuals with enduring EDs.

P362

Inpatient Stabilization And Drop-Out In Family-Based Therapy For Children And Adolescents With Anorexia Nervosa: 1-Year Results On Frequency And Clinical Correlates.
Philine J. Köln¹, Linus Imken¹, Piet Adler¹, Daniel Le Grange^{1, 2}, Christoph U. Correll^{1, 3}, Verena Haas¹
¹Universitätsmedizin Charité Berlin, Berlin, Germany, ²University of California (Emeritus), San Francisco, CA, United States, ³Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, United States

Introduction: Family-based therapy (FBT) has emerged as a promising treatment alternative to inpatient multimodal treatment for youth with anorexia nervosa (AN). However, a subgroup requires inpatient stabilization (IPS) or drops out of FBT (Haas et al. 2023). We aimed to identify baseline predictors for need for IPS or FBT dropout in youth receiving FBT for AN. Methods: Demographic, clinical and psychometric data were assessed as part of a prospective study at Charité University Berlin. Two multivariable backward-elimination logistic regression analyses were conducted using i) IPS before/during FBT and ii) dropout as dependent variables, entering all significant variables (p<0.05) from the univariate analyses into the initial model. Results: Among 68 patients (14.7±1.76 years, 92.6% female, 78.9±4.97 percent median body mass index) 27 (42.2%) required IPS before (n=23, 35.9%) and/or during (n=8, 12.3%) FBT (39,6±27.1 [15-83] days until admission) and 20 (29.4%) dropped out of FBT after 114,9±62.3 [26-252] days. An independent multivariable predictor (IMP) for IPS before/during FBT was a high Compulsive Exercise Test score (OR=1.02, p=0.009; R²=0.152). IMPs for FBT dropout were IPS before/during FBT (OR=10.40, p=0.021), high Eating Disorder Examination Questionnaire restraint scores (OR=2.70, p=0.008) and weight suppression (highest - baseline weight; OR=1.22, p=0.036) (R²=0.545). Conclusions: Identifying predictors for IPS and early FBT dropout may help personalise FBT for youth with AN.

P363

Off-Label Metreleptin Treatment In Adolescents With Anorexia Nervosa: A Case Series
Helene Krauss, Andreas Karwautz, Paul Plener, Konstantin Kopp, Stefanie Truttmann, Dunja Mairhofer
Medical University of Vienna, Department of Child and Adolescent Psychiatry, VIenna, Austria

Background: Leptin plays a key role in the physiological adaptation to starvation. In patients with anorexia nervosa, loss of fat mass leads to low leptin levels, which are associated with hormonal and metabolic dysregulation. The aim was to describe clinical observations on the effects of an experimental off-label subcutaneous metreleptin treatment as an adjunct to standard inpatient care.

Methods: This case series included four adolescent patients with anorexia nervosa, aged 14–18 years, who received additional metreleptin during inpatient treatment. Daily doses ranged from 3.0 to 11.6 mg. Visual analogue scales (VAS) were completed daily by both patients and the treatment team. Safety monitoring included daily assessment of vital signs, regular laboratory testing, and continuous glucose monitoring. Results: During metreleptin treatment, improvements in social interaction were observed. Some patients also reported reduced rumination, decreased drive for physical activity, reduced body image disturbance, and improved mood. These changes were not observed in all patients. Continued multimodal standard treatment remained clinically important throughout the intervention.

Conclusion: These case reports suggest that experimental off-label metreleptin treatment may represent a potentially useful adjunctive option in adolescent patients with anorexia nervosa. Further randomized controlled trials are required to evaluate efficacy and safety.

P364

A Community-Based &Ldquo;Balancing Home&Rdquo; As An Alternative To Inpatient Care For Eating Disorders: Two-Year Outcomes From A Novel Residential Service Model In Israel
Yael D Lewis^1,2,3, Adit Zohar Beja², Daniel Stein^3,4,5
¹Hadarim Eating Disorder Center, Shalvata Mental Health Center, Hod Hasharon, Israel, ²Hashvil Eating Disorder Residential Service , Holon, Israel, ³Gray Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, ⁴Pediatric Psychosomatic Department, Safra Children’s Hospital Sheba Medical Center, Tel Hashomer, Israel, ⁵Eating Disorders Unit, Maayanei Hayeshua Medical Center, Bnei Brak, Israel

“Hashvil” balancing home is a pioneering community-based residential model designed as an alternative to full inpatient hospitalization for women with complex eating disorders (EDs), the first to open in Israel. We aimed to describe the clinical characteristics and treatment outcomes of the first two years of its operation 2023-2025. A descriptive observational analysis was conducted using routinely collected clinical and administrative data. A total of 92 patients were treated over two years. Upon admission, mean illness duration was 8.8 years, with 81% of patients diagnosed with anorexia nervosa (AN), and 56% diagnosed with comorbid psychiatric conditions. A history of a prior ED hospitalization was found in 52%, while 19% had a prior psychiatric admission. In AN patients mean BMI increases of +1.04 in year one and +1.27 in year two were found. Treatment completion rates were 63.6% in the first year and 70.8% in the second year. Post-discharge, 54% of patients were referred to outpatient low-intensity treatment, 21% to day care programs, and 13% to long-term ED residential rehabilitation settings, while only 4% required full hospitalization. These findings suggest this residential treament model may achieve meaningful clinical stabilization and reduce reliance on inpatient services. Further prospective controlled trials are required to compare the short-term treatment outcomes with those of full admission or day care programs, and explore long-term outcomes.

P365

Heterogenous Response Patterns In Percent Expected Body Weightamong Adolescents With Avoidant/Restrictive Food Intake Disorder Receiving Family-Based Treatment
Qianheng Ma, Brittany E. Matheson, Ainsley Cogburn, HaLi Boyce, James D. Lock
Stanford University, Stanford, CA, United States

Introduction: Treatment response in avoidant/restrictive food intake disorder (ARFID), indexed by % expected body weight (%EBW), is heterogeneous, with distinct trajectories emerging during family-based treatment (FBT). Parental self-efficacy (PvA), a core target of FBT, may co-evolve with these patterns. Methods: A total of 98 ARFID adolescents were randomized equally to FBT or psychoeducational motivational therapy (PMT). %EBW and PvA were assessed at baseline (BL), month 1, 2, end of treatment (EOT; month 4), and after 6-month follow-up (6mFU; month 10). Patterns of change in %EBW from BL were identified using k-means clustering, and PvA change was compared across subgroups and treatments. Results: 5 subgroups were identified: high increase (n=7 vs 6, FBT vs PMT), moderate increase (22 vs 6), low increase (17 vs 9), gradual decrease (8 vs 12), and fast decrease (2 vs 8). A greater proportion of FBT subjects were in the increasing subgroups compared to PMT (79.2% vs. 59.2%, χ² p<.01). PvA change at EOT did not differ across subgroups (p=.07) but was greater in FBT than in PMT (3.4[3.3] vs. 0.6[2.6], p<.01). After EOT, gains were maintained in FBT (2.8[3.0]) but showed greater variability in PMT (1.6[3.7]), with no significant treatment difference (p=.13) at 6mFU. Conclusions: FBT was associated with better %EBW response patterns than PMT. Heterogeneity in %EBW and PvA trajectories suggests variability in both treatment response and underlying mechanisms over time.

P366

Defining Early Weight Gain As A Predictor Of Inpatient Treatment Outcomes In Eating Disorders
Mary K. Martinelli, Colleen C. Schreyer, Angela S. Guarda
Johns Hopkins University, Baltimore, MD, United States

Introduction: Early weight gain during inpatient eating disorders (EDs) treatment is considered a key indicator of progress, yet the optimal time window for assessing early change is unclear. This study compared 7-day and 14-day weight gain as predictors of treatment outcomes. Method: Participants were 415 underweight individuals undergoing inpatient ED treatment. Early weight change was operationalized as the rate of weight gain over either the first 7 or first 14 days of hospitalization. Regression models evaluated associations between early weight change and discharge outcomes, including discharge BMI, length of stay, goal weight attainment, and discharge for clinical improvement. Models controlled for diagnosis and admission BMI. Results: The 7-day rate of weight gain positively predicted discharge BMI (B = 0.69, p <.001) but was not associated with length of stay (p = .19), goal weight attainment (p = .12), or clinical improvement (p = .14). In contrast, greater 14-day weight gain was associated with higher discharge BMI (B = 1.38, p <.001), shorter length of stay (B = −7.90, p = .002), increased odds of achieving goal weight (OR ≈ 2.22, p = .004), and greater likelihood of clinical improvement at discharge (OR ≈ 2.10, p = .007). Discussion: Several factors likely contribute to the finding that 14-day weight gain is a more robust and clinically useful predictor of inpatient outcomes than 7-day change. Extending the early response window may improve prognostic utility.

P367

Design. Implement. Sustain: Advancing Program-Led Interventions For Eating Disorders
Bernou Melisse^1,2,3,4, Sanne Marcic¹, Annemarie van Elburg^1,3
¹Co-eur, Utrecht, Netherlands, ²American Center for Psychiatryand Neurology, Abu Dhabi, United Arab Emirates, ³Department of Clinical Psychology, Utrecht University, Utrecht, Netherlands, ⁴Department of Medical and Clinical Psychology, University of Tilburg,, Tilburg, Netherlands

Most individuals with EDs never receive treatment, due to long waiting lists, lack of therapists, geographical and financial constraints. Scalable and accessible interventions, such as program‑led interventions, which can improve access to specialized care and reduce waitlists are needed. Yet their implementation in routine clinical care is limited. Program-led interventions. Program-led interventions, such as (un)guided self-help CBT offer a promising solution. They require fewer therapist resources, can be delivered digitally, and efficacy is proven for binge eating (abstinence rates ≤58%, clinically significant improvement ≤80%). Outcomes are comparable to conventionally delivered CBT for recurrent binge eating, while costs are markedly reduced. Barriers and optimization. Implementation, remains limited. Challenges include high attrition in unguided formats, variable adherence, limited user and therapist acceptance, and concerns about safety monitoring. Evidence suggests that specialist guided formats, integration into stepped-care systems, co-design with users, persuasive design features, and personalized feedback can enhance engagement and outcomes. Embedding safety protocols is important to ensure responsible use in routine care. Implications. Program-led interventions represent an evidence-based, scalable, and cost-effective strategy to close the treatment gap. Prioritizing design, implementation, and sustainability will be critical to maximize clinical and societal impact.

P368

Understanding Illness And Recovery In Eating Disorders: A Qualitative Study Of Group Psychotherapy
Alessio Maria Monteleone, Marco Carfagno, Flavia Martinelli, Andrea Costantini, Valeria Ruzzi, Eugenia Barone
University of Campania L. Vanvitelli, Naples, Italy

Objectives
Illness and recovery in eating disorders (EDs) are often defined mainly by symptom reduction, overlooking their subjective and multidimensional nature. This study explored how individuals with EDs conceptualize illness and recovery, and how these meanings may change through group psychotherapy. Methods
A qualitative study using reflexive thematic analysis was conducted. Ten adult outpatients with EDs participated in semi-structured interviews at the end of a group psychotherapy program within a multidisciplinary treatment setting. Results
Before the group, illness and recovery were primarily described in symptom-based and externally driven terms. After participation, individuals developed a more integrated understanding, linking EDs to emotional and interpersonal processes. Recovery was seen as a multidimensional process involving emotional awareness, self-acceptance, relational understanding, and personal agency. Peer sharing and connection played a key role in these changes. Conclusions
Group psychotherapy may promote a shift from a symptom-focused view of EDs to a more holistic and personally meaningful understanding of illness and recovery. Emotional awareness, self-acceptance, and interpersonal connection emerge as central elements in supporting recovery.

P369

Comparative Safety And Effectiveness Of Mirtazapine Vs Cyproheptadine In Adolescents With Avoidant/Restrictive Food Intake Disorder
Srutik Nagamalla, Kelsey Delph, Kelsey Hagan
Virginia Commonwealth University, Richmond, VA, United States

Introduction: Mirtazapine is frequently used off-label in Avoidant/Restrictive Food Intake Disorder (ARFID) for its orexigenic effects. However, the suicidality black box warning, derived from depression trials, compounded by a lack of pediatric FDA approval, often limits pediatric ARFID use. Hence, clinicians prioritize cyproheptadine, a familiar non-psychotropic comparator. This study compared the psychiatric safety and nutritional effectiveness of mirtazapine against cyproheptadine.

Methods: With the TriNetX network, a retrospective cohort of adolescents (10-18 years) with ARFID (ICD-10: F50.82) was identified. Cohorts were matched 1:1 through propensity scores for age, sex, psychiatric comorbidities, SSRI use, ED visits, and social determinants of health. A 5-year washout excluded prior suicidality or self-harm. Primary outcomes were treatment-emergent suicidality and/or self-harm and malnutrition resolution assessed longitudinally from the index date.

Results: In the matched cohort (N=472), both groups showed negligible psychiatric safety signals, with events falling below reporting thresholds. Malnutrition resolution rates were 75.3% for mirtazapine and 62.5% for cyproheptadine (HR=0.952, p=0.81).

Conclusions: Mirtazapine and cyproheptadine have similar safety and effectiveness for malnutrition resolution in adolescents with ARFID. Findings suggest that treatment-emergent suicidality or self-harm in mirtazapine is low, indicating it may be a pharmacological option for adolescent ARFID.

P370

Application Of Dynamical Systems Modeling And Ecological Quasi-Experiments To Develop A Precision Psychiatry Digital Intervention For Transdiagnostic Eating Disorders
Emily K. Presseller¹, Falzah Farooq¹, Nicholas C. Jacobson¹, J. Graham Thomas², Lisa A. Marsch¹
¹Dartmouth College, Hanover, NH, United States, ²Brown Alpert School of Medicine, Providence, RI, United States

Introduction: 80% of people with eating disorders (EDs) have never accessed treatment due to barriers like stigma, treatment costs, and lack of specialized providers. Highly disseminable, potent digital interventions are critically needed. Self-help digital interventions offer promise for improving outcomes, but their efficacy is modest, likely due in part to lack of personalization to between- and within-patient heterogeneity. Methods: This presentation will discuss using dynamical systems modeling and micro-randomized just-in-time adaptive interventions (JITAIs) to improve efficacy of a precision digital intervention. The study uses person-specific dynamical systems modeling of time series data (ecological momentary assessments, sensors) to understand individual ED behavior (i.e., dietary restriction, binge eating, compensatory behaviors) risk. Micro-randomized JITAIs prompting use of cognitive-behavioral therapy (CBT) skills are delivered when the individual’s dynamical system indicates elevated ED behavior risk to test the causal effects of CBT skills. The study aims to evaluate person-centered dynamical models for predicting ED behaviors and test hypothesized effects and mechanisms of CBT skills on ED behaviors. 170 adults with EDs will complete ecological data collection (16 weeks) and receive JITAIs (10 weeks). Results: Preliminary results will be presented. Conclusions: Findings will set the stage for future evaluation of a personalized, optimized digital intervention for EDs.

P371

Deep Learning Prediction Of Eating Disorder Symptoms From Physiological Signals
Christina Ralph-Nearman ¹, Mahdi Hammami², Andrew Karem³, Hichem Frigui²
¹Health & Human Performance, Palm Beach Atlantic, West Palm Beach, FL, United States, ²Department of Computer Science & Engineering, University of Louisville, Louisville, KY, United States, ³Department of Computer Science, Bellarmine University, Louisville, KY, United States

Introduction:
Approximately half of individuals who seek traditional treatment for eating disorders (EDs) do not respond to current interventions. This underscores the need for personalized, real-time support. Emerging evidence suggests physiological data from wearables can detect indication on symptom onset. Core cognitive-affective states (e.g., anxiety, fatigue, fear of weight gain) may precede maladaptive ED behaviors, presenting an opportunity for early intervention. Methods:
Fourteen women diagnosed with an ED (Mage=29.2±7.1) completed a 30-day ecological momentary assessment protocol. Participants reported symptom severity (0–100) four times daily while wearing wrist sensors capturing heart rate, electrodermal activity, blood volume pulse, skin temperature, and movement. ~160 hours of physiological data were preprocessed, time-aligned with self-reports, and used to train deep learning models. Results:
Models achieved a mean absolute error (MAE) of 15.73 in predicting symptom severity. Due to heterogeneity across individuals and diagnoses, generalizability was tested on unseen participants. Personalized models significantly improved performance, with several participant-specific models achieving MAE <10. Conclusions:
Individualized deep learning models can accurately predict momentary ED symptoms using wearable data within daily life. This approach supports development of just-in-time adaptive interventions, offering scalable, real-world support for diverse ED populations.

P372

Mind Binges: The Role Of Feedback In A Randomized Controlled Inhibition Training For Binge Eating
Kathrin Schag^1,2,3, Sebastian Max^1,2,3, Simone Weller^3,4, Veronika Lossa^3,5, Andreas Fallgatter^3,4, Stephan Zipfel^1,2,3, Christian Plewnia^3,4, Katrin Giel^1,2,3
¹University Hospital Tübingen, Department of Psychosomatic Medicine and Psychotherapy, Tübingen, Germany, ²Centre of Excellence for Eating Disorders Tübingen (KOMET), Tübingen, Germany, ³German Center for Mental Health (Deutsches Zentrum für Psychische Gesundheit, DZPG), partner site Tübingen, Tübingen, Germany, ⁴University Hospital Tübingen, Department of Psychiatry and Psychotherapy, Neurophysiology & Interventional Neuropsychiatry, Tübingen, Germany, ⁵Lived experience representative, German Center for Mental Health (Deutsches Zentrum für Psychische Gesundheit, DZPG), partner site Tübingen, Tübingen, Germany

Introduction: Binge-type eating disorders constitute a transdiagnostic group of eating disorders characterized by increased impulsivity. In particular, reduced inhibitory control is considered a central mechanism in the development and maintenance of binge eating. It appears to be modified by computer-assisted trainings; however, the role of feedback in such inhibition trainings (IT) has to be investigated. Methods: MIND BINGES is a prospective, randomized controlled proof-of-principle trial. 67 patients with regular binge eating were randomized to an IT with feedback, IT without feedback, or a control group (CG). The IT is based on an antisaccade paradigm using high-calorie foods and comprises six sessions over two weeks. The primary endpoint is the change in binge eating frequency after completion of the IT and at a 3-month follow-up. Secondary endpoints include eating disorder psychopathology, inhibitory control, impulsivity, and self-efficacy. Results: Results indicate that binge eating frequency was significantly reduced in all groups after the IT. IT with feedback was superior to the IT without feedback and CG. These differences washed out at 3-month follow-up. Concerning secondary outcomes, all groups improved over time. Conclusions: Feedback contributes to short term reductions in binge eating and seems crucial for the development of mechanism-based interventions. These findings add to a better understanding of the mechanisms underlying the treatment of binge eating.

P373

Evaluating A Novel Eating Disorder Prevention Program Targeting Overvaluation Of Weight And Shape
Sareena Shah¹, Amaya Aquino², Heather Shaw¹, Eric Stice¹
¹Stanford University, Palo Alto, CA, United States, ²University of California, Santa Cruz, Santa Cruz, CA, United States

The Body Project dissonance-based eating disorder prevention program has reduced eating disorder risk factors, symptoms, and future onset in numerous trials conducted by independent teams. However, a prospective study found thin ideal pursuit, the Body Project’s intervention target, did not predict future onset of anorexia nervosa. Fortunately, the prospective study found weight/shape overvaluation predicted future onset of all major types of eating disorders. We therefore conducted a trial comparing the Body Project to Priorities, a new dissonance-based program targeting weight/shape overevaluation, to determine which is more effective at reducing eating disorder risk factors and symptoms. Adolescent girls and young women (N = 87; ages 13–25) were randomized to Body Project or Priorities groups, which were delivered virtually by peer educators, and completed self-report surveys at pretest, posttest, and 1-month follow-up. Reductions in eating disorder risk factors and symptoms did not significantly differ between intervention conditions, but average within-condition Cohen’s d reductions in outcomes for Priorities were similar to or larger than within-condition reductions in Body Project participants observed in this and six prior trials (e.g., .81 for Priorities compared to .53 for the Body Project). Results suggest weight/shape overvaluation may be a valuable new eating disorder prevention intervention target, warranting further intervention refinement and evaluation.

P374

Inpatient Post‑Meal Activity And Eating‑Disorder Behaviors: An Ecological Momentary Assessment (Ema) Study Incorporating A Structured Activity Protocol
Kristin Stedal¹, Line Wisting^1,2, Joseph Wonderlich^3,4, Anne Louise Wennersberg¹, Annette Skarsbakk⁵, Ida Aarmo⁵, Selma Øverland Lie¹, Ingrid Funderud¹
¹ Regional Department of Eating Disorders, Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway, ² Department of Psychology, Oslo New University College, Oslo, Norway, ³ Department of Psychiatry, University of North Dakota School of Medicine and Health Sciences, Fargo, NC, United States, ⁴ Division for Biobehavioral Research, Sanford Research, Fargo, ND, United States, ⁵ Eating Disorder Unit, Department of Psychiatry, Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway

Introduction: This study used ecological momentary assessment (EMA) to investigate whether permitting structured light activity after meals is associated with a lower likelihood of ritualized eating behaviors among inpatients receiving specialist treatment for eating disorders. Method: Thirty-three inpatients completed a two-week counterbalanced within-subject crossover EMA protocol. One week consisted of standard post-meal rest and one week allowed for structured light post-meal activity. A binomial mixed‑effects model with participant‑level random intercepts tested whether the likelihood of ritualized eating behaviors differed between condition. Results: Participants completed 1,503 EMA prompts (81.3% compliance), of which 1,192 were meal-related. Across the two conditions, ritualized eating behaviors were endorsed on 29.6% of the meal-related assessments. Participants were significantly less likely to engage in ritualized eating behaviors during weeks allowing post-meal activity compared with rest-only weeks (B = −0.70, SE = 0.19, p = .0002), corresponding to an approximately 50% reduction in odds. Conclusion: Structured light post-meal activity was associated with a lower momentary likelihood of ritualized eating behaviors in an inpatient setting suggesting that supervised post-meal movement may help interrupt ritual engagement.

P375

Adapting And Implementing The Body Project As Universal Prevention Program For Adolescents In Austria: First Insights
Karin Waldherr¹, Friedrich Teutsch¹, Eric Stice²
¹FERNFH Distance Learning Univ. of Applied Sciences, Wiener Neustadt, Austria, ²Stanford Medicine, Stanford, CA, United States

Introduction: The project aims to tailor the evidence-based intervention Body Project (BP) and implementation strategies to the cultural context for adolescents aged 15-18 in Austria, and to prepare for the nationwide rollout. Methods: The piloted implementation strategies include all-girls and mixed-gender groups in schools and in out-of-school youth work. The on-site groups are led either by two trained professionals, or by one trained professional and a student. We conduct a hybrid effectiveness-implementation study with a focus on implementation. The mixed-methods design includes interviews with facilitators, recordings and documentations of workshops, focus groups with participants, as well as pre- and post-intervention surveys. Results: Implementing the 4-session version in schools requires flexibility from teachers and BP facilitators. First analyses (n=100) yield small to medium within-group effect sizes (Cohen d) on thin-ideal internalization, dieting and body dissatisfaction. Participants reported that the workshops had led to a better understanding, greater respect and more empathy within school classes, including between the genders. Implementation was even more challenging in youth work, and the dropout rate was high. Conclusions: The average effects on eating disorder risk factors may be small. However, implementing the Body Project in schools could positively influence school climate, for which there is growing evidence of mental health benefits.

P376

Eating Disorder Treatment And Service Experiences Of Gender Diverse And Neurodivergent Adults
Grace H. Williams¹, Max Keith^{1, 2}, Lived Experience Advisory Group , Marc O. Williams¹, Catherine R. G. Jones¹, Kate Cooper^{3, 4}, Josie Henley¹, Kai S. Thomas¹
¹Cardiff University, Cardiff, Wales, ²University of Birmingham, Birmingham, United Kingdom, ³University College London, London, United Kingdom, ⁴University of Bath, Bath, United Kingdom

Introduction. Eating disorders (EDs) disproportionately affect trans and gender diverse (TGD) people, autistic people, and people with ADHD. TGD and neurodivergent individuals present with more severe symptoms and more complex, intersecting treatment needs than cisgender allistic peers. However, research has not yet examined how gender diversity, autism, and ADHD shape ED treatment experiences.

Methods. 261 neurodivergent TGD adults (79.7% AFAB; M age = 27.4 years) with lived experience of an ED completed an online survey. Participants responded to open-ended questions about the impact of gender identity and neurodivergence on accessing ED treatment. Responses were analysed using reflexive thematic analysis.

Results. Two preliminary themes were identified: 1) "The system is not built for me" which describes feeling misunderstood and overlooked in treatment, with subthemes: neuronormative frameworks, the burden of complexity, and trans identity as incompatible with treatment and 2) "Seeking help as its own harm" which encapsulates fear and safety concerns when accessing ED care, with subthemes: healthcare as an unsafe space and the calculated cost of recovery.

Conclusions. Current systems may inadvertently fail to meet the needs of neurodivergent TGD people and deter help-seeking. Findings highlight the need for gender- and neurodivergent-affirming ED treatment that addresses the intersecting needs of this underserved group.

P377

And What About The Siblings? &Ndash; The Psychological Burden Of Siblings Of Young Patients With Anorexia Nervosa (An)
Ingar Zielinski-Gussen^1,2, Lena Wassermann¹, Sarah Grüneberg³, Brigitte Dahmen¹, Beate Herpertz-Dahlmann¹
¹Department of Child and Adolescent Psychiatry, Psychotherapy and Psychosomatics, University Hospital RWTH Aachen, Aachen, Germany, ²Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, LVR University Hospital Essen, Essen, Germany, ³Department of Psychiatry, Psychotherapy and Psychosomatic Medicine of Childhood and Adolescence, University Hospital Leipzig, Leipzig,

Introduction. Adult siblings of AN patients are known to experience significant psychological burden. Yet, minor siblings remain almost entirely unstudied, and targeted support is lacking. This study investigates psychological burden in minor siblings of AN patients and examines influencing factors. Methods. 88 siblings (aged 7–17) of AN patients (n=59) were compared to siblings of patients with internalizing disorders (n=29) using the KIDSSCREEN-27, BDI-Y, and a newly developed illness-specific questionnaire. Results. Both groups showed significantly higher depressive symptoms and lower quality of life compared to normative data. AN siblings showed a trend toward higher illness-specific burden than controls. Older siblings and sisters were significantly more burdened; treatment setting had no effect. Conclusions. Minor siblings of AN patients show relevant psychological burden, with older siblings and sisters being particularly affected. Routine screening and targeted support interventions are warranted.

P378

Bidirectional Temporal Relationships Between Emotional State And Eating Across Eating Disorders: A Network Approach
Jens Blechert, Sercan Kahveci, Julia Reichenberger, Ann-Kathrin Arend, Alessandra C. Mansueto, René Freichel, Ulrich Voderholzer

Introduction. Models of eating disorders propose that emotions and eating-related behaviours influence each other in self-reinforcing cycles, yet it remains unclear whether these temporal dynamics differ across diagnoses. Methods. Women with restrictive anorexia nervosa (AN-R; n=29), binge-purge anorexia nervosa (AN-BP; n=26), bulimia nervosa (BN; n=42), binge-eating disorder (BED; n=37), and healthy controls (HC; n=57) completed ecological momentary assessment six times per day for eight days. Negative and positive emotions, hunger, desire to eat, calorie intake, and binges were reanalysed using modified vector-autoregressive networks. Results. Eating-disorder groups showed more prospective emotion-eating associations than HC. Calorie intake predicted later increases in negative affect or decreases in positive affect in all eating-disorder groups. Binges predicted later negative affect in AN-BP, BN, and BED, with effects lasting up to 10 hours. AN-R showed positive emotional eating, whereas BED showed negative emotional eating, with worry predicting desire to eat and hunger and irritation predicting calorie intake. Negative emotions did not prospectively predict binges. Conclusions. Post-eating dysphoria appears transdiagnostic across eating disorders. Some groups also showed restriction-promoting feedback loops in which eating was followed by negative affect, which was then followed by reduced willingness to eat.

9:00 - 12:00 PM	Festsaal Ballroom
Pre-Conference Workshop: Taking Charge of your Career: A Professional Development Workshop for Early-Career Academics and Clinical Scholars

2:15 - 3:45 PM	Festsaal Ballroom
Symposium: Shaping the future of eating disorder care: The role of clinical quality registries

4:15 - 6:00 PM	Festsaal Ballroom CD
Parallel Paper Session 2: Treatment

4:15 - 6:00 PM	Festsaal Ballroom AB
Parallel Paper Session 1: Biological

6:00 - 7:30 PM	Palais Coburg I-III / Foyer II
Welcome Reception and Poster Session 1

10:00 - 11:30 AM	Festsaal Ballroom
Symposium: Rethinking Eating Disorders: Bold New Targets, Treatments, and Technologies

1:00 - 2:45 PM	Festsaal Ballroom CD
Parallel Paper Session 4: Treatment

1:00 - 2:45 PM	Festsaal Ballroom AB
Parallel Paper Session 3: Biological

3:15 - 4:45 PM	Festsaal Ballroom
Symposium: Working across the age divide: Treatment innovations for adolescents and emerging adults with anorexia nervosa

4:45 - 6:15 PM	Palais Coburg I-III / Foyer II
Poster Session 2

9:00 - 10:45 AM	Festsaal Ballroom
Top Abstracts & Awards Session

11:45 - 1:15 PM	Palais Coburg I-III / Foyer II
Poster Session 3 / Lunch