Purpose: The association between binge eating and obesity is increasing. Treatments for disorders of recurrent binge eating comorbid with obesity reduce eating disorder (ED) symptoms, but not weight. This study investigated the efficacy and safety of introducing a weight loss intervention to the treatment of people with disorders of recurrent binge eating and a high body mass index (BMI).
Methods: A single-blind randomized controlled trial selected adults with binge eating disorder or bulimia nervosa and BMI ≥ 27 to < 40 kg/m2. The primary outcome was sustained weight loss at 12-month follow-up. Secondary outcomes included ED symptoms. Mixed effects models analyses were conducted using multiple imputed datasets in the presence of missing data.
Results: Ninety-eight participants were randomized to the Health Approach to Weight Management and Food in Eating Disorders (HAPIFED) or to the Cognitive Behavioural Therapy-Enhanced (CBT-E). No between-group differences were found for percentage of participants achieving weight loss or secondary outcomes, except for reduction of purging behaviour, which was greater with HAPIFED (p = 0.016). Binge remission rates specifically at 12-month follow-up favoured HAPIFED (34.0% vs 16.7%; p = 0.049). Overall, significant improvements in the reduction of ED symptoms were seen in both groups and these were sustained at the 12-month follow-up.
Conclusion: HAPIFED was not superior to CBT-E in promoting clinically significant weight loss and was not significantly different in reducing most ED symptoms. No harm was observed with HAPIFED, in that no worsening of ED symptoms was observed. Further studies should test approaches that target both the management of ED symptoms and the high BMI.
Level of evidence: Level I, randomized controlled trial TRIAL REGISTRATION: US National Institutes of Health clinical trial registration number NCT02464345, date of registration 1 June 2015.
Keywords: Binge-eating disorder; Bulimia nervosa; Therapy; Weight loss.