Cognitive Behavioral Therapy for Binge-Eating Disorder in Individuals With Type 2 Diabetes: A Pilot Randomized Controlled Trial

Objective: To evaluate the feasibility of a randomized pilot trial of group-based cognitive behavioral therapy (CBT) for binge eating disorder (BED) in individuals with type 2 diabetes, and to estimate exploratory clinical outcomes to inform the design of a future efficacy trial. Method: Thirty-four participants with type 2 diabetes and BED were randomized 1:1 to group CBT or waitlist. Feasibility outcomes included recruitment, randomization, intervention adherence, and follow-up completion. Exploratory clinical outcomes were analyzed using an intention-to-treat mixed model, with weekly binge-eating episodes evaluated as the primary clinical outcome for a future efficacy trial. Other exploratory clinical outcomes included other BED symptoms and glycated hemoglobin (HbA1c). Results: Recruitment was resource-intensive, with 2646 individuals screened to randomize 34 participants. Randomization was completed as planned, but treatment initiation and follow-up completion were lower in the group CBT arm. Postintervention data on weekly binge-eating episodes were available for 11/17 participants in the CBT group and 16/17 in the waitlist group. This differential follow-up may have introduced attrition bias. The exploratory between-group estimate for binge-eating episodes favored group CBT, with an adjusted difference in change of −2 episodes per week (95% CI: −4.81 to 0.68), corresponding to Cohen's d = −0.62 (95% CI: −1.45 to 0.21). Exploratory clinical outcome estimates were intended to inform future trial design rather than to test efficacy. Discussion: Group CBT delivery appeared acceptable among participants who initiated treatment, but recruitment and follow-up require refinement before proceeding to a future efficacy trial.