Oral Presentation Australian and New Zealand Obesity Society Annual Scientific Conference 2026

Body mass index outcomes in adults following behavioural weight management interventions that measure eating disorder symptoms: a secondary analysis of individual participant data using pairwise and network meta-analysis (143790)

Rabia Khalid 1 2 , Hiba Jebeile 1 2 , Louise Baur 1 3 , Sarah P Garnett 1 , Isabelle R Jardine 1 2 , Sasha J Lorien 1 , Hannah Melville 1 2 , Anna Lene Seidler 4 5 6 , Sol Libesman 4 , Natalie B Lister 1 2
  1. The Children’s Hospital Westmead Clinical School, University of Sydney, Sydney, NSW, Australia
  2. Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
  3. Weight Management Services, The Children’s Hospital at Westmead, Westmead, NSW, Australia
  4. National Health and Medical Research Council Clinical Trials Centre, The University of Sydney, Sydney, NSW, Australia
  5. Department of Child and Adolescent Psychiatry, University Medical Centre Rostock, Rostock, Mecklenburg‑Vorpommern, Germany
  6. German Center for Child and Adolescent Health (DZKJ), Partner Site Greifswald/Rostock, Rostock, Mecklenburg‑Vorpommern, Germany

Background: Behavioural weight management interventions that assess eating disorder symptoms show an average reduction or no change in symptoms over time. There is a need to examine whether these interventions also achieve the common goal of weight loss.  

Aims: This study aimed to examine change in body mass index (BMI) for adults in behavioural weight management trials that assessed eating disorder symptoms compared to no-treatment control and based on intervention intensity.

Methodology: This secondary analysis used individual participant data (IPD) from the Eating Disorders In weight-related Therapy (EDIT) Collaboration. This included behavioural weight‑management interventions that assessed eating‑disorder symptoms in people with overweight/obesity. Change in BMI was examined through 1) two-stage pairwise meta-analyses comparing any intervention to no-treatment control at 12-months post-baseline, and 2) two-stage network meta-analyses based on low, medium, or high intervention intensity at post-intervention. Intervention intensity categories reflected the dose (duration and frequency of contact), and breadth of behaviour change content and strategies (e.g. diet, physical activity) used.

Results: Of the 36 trials (k) in the EDIT Collaboration dataset, 9 were eligible (n=1679; mean age=48.5 years; BMI=32.2 kg/m²; 81% female). Pairwise meta-analyses revealed a significant reduction in BMI (k=2; n=529 MD= -2.04, 95%CI -3.41, -0.67, tau=1.07) compared to no-treatment control. Network meta-analyses (k=9, n=1679) found a significant reduction in BMI for high (MD= -2.62, 95%CI -3.63, -1.61), medium (MD= -1.07, 95%CI –2.06, -0.08) and low (MD= -1.33, 95%CI -2.55, -0.11) intensity interventions, compared to control.

Conclusion: Relative to no treatment, receiving any behavioural weight management intervention resulted in clinically meaningful weight loss at 12 months post-baseline, with high intensity interventions having the greatest reduction in BMI at post-intervention. Behavioural weight management interventions that assessed eating disorder symptoms were associated with favourable weight-related outcomes alongside potential decreased eating disorder symptoms.