Acceptance-Based Versus Standard Behavioral Treatment for Obesity: Results from the Mind Your Health Randomized Controlled Trial

Objective: To evaluate the efficacy, as well as potential moderators and mediators, of a revised acceptance-based behavioral treatment (ABT) for obesity, relative to standard behavioral treatment (SBT). Methods: Participants with overweight and obesity (n = 190) were randomized to 25 sessions of ABT or SBT over 1 year. Primary outcome (weight), mediator, and moderator measurements were taken at baseline, 6 months, and/or 12 months, and weight was also measured every session. Results: Participants assigned to ABT attained a significantly greater 12-month weight loss (13.3% +/- 0.83%) than did those assigned to SBT (9.8% +/- 0.87%; P = 0.005). A condition by quadratic time effect on session-by-session weights (P = 0.01) indicated that SBT had a shallower trajectory of weight loss followed by an upward deflection. ABT participants were also more likely to maintain a 10% weight loss at 12 months (64.0% vs. 48.9%; P = 0.04). No evidence of moderation was found. Results supported the mediating role of autonomous motivation and psychological acceptance of food-related urges. Conclusions: Behavioral weight loss outcomes can be improved by integrating self-regulation skills that are reflected in acceptance-based treatment, i.e., tolerating discomfort and reduction in pleasure, enacting commitment to valued behavior, and being mindfully aware during moments of decision-making.