Two thirds of the adults in the United States are overweight or obese. Binge eating is a barrier to treatment adherence and sustained weight loss, and can be seen as a form of experiential avoidance. The current study analyzed the impact of binge eating on weight reduction in a previously published study of a 1-day acceptance and commitment therapy (ACT) workshop (N = 83) and the psychological processes accounting for the binge-eating results. ACT participants reported less binge eating, which in turn significantly mediated changes in weight. Mediation analyses also showed that reductions in binge eating were mediated by changes in experiential avoidance. The study suggests that ACT and its targeted processes of change may be particularly relevant to binge eating, and that targeting binging is a possible pathway for improving weight management. (Contains 1 figure and 3 tables.)