Physical and mental health outcomes of an integrated cognitive behavioural and weight management therapy for people with an eating disorder characterized by binge eating and a high body mass index: a randomized controlled trial

BACKGROUND: Bulimia nervosa (BN) and binge eating disorder (BED) are eating disorders (EDs) characterized by recurrent binge eating. They are associated with medical complications, impaired adaptive function and often a high BMI, for which a multidisciplinary treatment approach may be needed. This study explored the efficacy of a novel intervention integrating Cognitive Behavioural Therapy- Enhanced (CBT-E) and weight management for people with recurrent binge eating episodes and high BMI with respect to physical, psychopathological and quality of life outcomes. METHODS: Ninety-eight adults diagnosed with BN, BED, or Other Specified/Unspecified Feeding or Eating Disorder (OSFED/UFED) and BMI ≥ 27 to <40 kg/m(2) were randomized to a multidisciplinary approach, the Healthy APproach to weIght management and Food in Eating Disorders (HAPIFED) or to CBT-E. Metabolic parameters, health-related quality of life, general psychological and ED symptoms and ED diagnostic status outcomes are reported. Data were analyzed with mixed effects models adopting multiple imputed datasets where data were missing. RESULTS: Both HAPIFED and CBT-E showed statistical significance for the time effect, with reduction in stress (p < 0.001), improvement in mental health-related quality of life (p = 0.032), reduction in binge eating severity (p < 0.001), and also in global ED symptoms scores (p < 0.001), with the significant changes found at end of treatment and sustained at 12-month follow-up. However, no statistical significance was found for differences between the interventions in any of the outcomes measured. Despite a high BMI, most participants (> 75%) had blood test results for glucose, insulin, triglycerides and cholesterol within the normal range, and 52% were within the normal range for the physical component of quality of life at baseline with no change during the trial period. CONCLUSION: Integrating weight and ED management resulted in comparable outcomes to ED therapy alone. Although adding weight management to an ED intervention had no adverse effects on psychological outcomes, it also had no beneficial effect on metabolic outcomes. Therefore, more intense weight management strategies may be required where indicated to improve metabolic outcomes. Safety will need to be concurrently investigated. TRIAL REGISTRATION: US National Institutes of Health clinical trial registration number NCT02464345, date of registration 08/06/2015. Changes to the present paper from the published protocol paper (Trials 18:578, 2015) and as reported in the Trial registration (clinicaltrials.gov) are reported in Supplementary File 1. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-022-04005-y.