Although bariatric surgery produces substantial weight-loss and improvements in medical co-morbidities, outcomes are heterogenous and a sizeable minority fail to achieve sufficient weight-loss. Loss-of-control (LOC) eating post-operatively is associated with marked distress and is a consistent predictor of suboptimal longer-term outcomes. This randomized controlled trial examined the effectiveness of two guided-self-help treatments (cognitive-behavioral therapy [gshCBT] and behavioral weight-loss [gshBWL]) to standard-of-care (SOC) comparison for reducing LOC-eating and weight.
140 patients with recurrent LOC-eating six months after bariatric surgery were randomly assigned (5:5:2 ratio) to one of three conditions: gshCBT (N=56), gshBWL (N=60), or SOC (N=24). Three-month treatments were delivered by trained allied-health clinicians to increase generalizability to bariatric-surgery settings. Independent assessments at baseline, monthly, and at post-treatment were performed by doctoral research-clinicians using established interviews/measures; post-outcomes were obtained for 89% of patients.
Mixed-models analyses (ITT all available data) revealed significant time-effects for both LOC frequency and weight loss but no significant interaction effects with the treatment conditions. ITT analyses of rates of abstinence from LOC-eating (30% for gshCBT, 27% for gshBWL 38% for SOC) and of proportion achieving 5% weight loss (23%, 25%, 20%) revealed no significant differences between treatments.
Findings suggest that guided-self-help versions of CBT and BWL did not show short-term effectiveness relative to standard-of-care (SOC) for treating LOC-eating or enhancing weight-loss in bariatric patients with LOC-eating. Overall, modest improvements in eating and weight-loss were observed that differed little between treatments. Post-operative patients with LOC eating may represent a treatment-resistant subgroup requiring more intensive specialist treatments.