Staats, S. B. (2017). An evaluation of the effectiveness of acceptance and commitment therapy in promoting physical activity in a hospital-based weight management program (Unpublished doctoral dissertation). Wichita State University, Wichita, Kansas.

One effective method of addressing obesity as a serious public health problem in the United States and worldwide has been through behavioral weight management programs. However, these programs have prototypically led to weight loss that is regained after approximately 6 months, leading scientists and practitioners to seek out improved protocols for maintenance of weight loss. Acceptance- and mindfulness-based approaches have been successfully employed in a number of health-related areas to improve patient outcomes. This study was an attempt to augment a traditional weight management program with acceptance and commitment therapy (ACT), in the hopes of improving outcomes, especially with respect to increasing patients’ physical activity. Participants were 137 patients referred by their physicians and enrolled in the maintenance phase of a hospital-based weight management program. Nearly a third of them (n = 45) received a 4-week module of ACT aimed at increasing psychological flexibility and values-oriented physical activity, while the remaining 92 continued to receive treatment-as-usual during this time, consisting of an evidence-based protocol that promoted regular physical activity and consumption of fruits, vegetables, and low-calorie meal replacement products. The ACT intervention failed to increase physical activity levels or show significant effects on any of the other outcome variables apart from males who received it losing more weight than other patients during the 4 weeks of treatment before then regaining it during 12 weeks of posttreatment. No expected dose-response or mediating relationships between reductions in experiential avoidance and treatment gains were found for the ACT group, although patients receiving it showed increased engagement in their weight management program based on higher attendance during posttreatment meetings. Limitations of the study and considerations for future research are discussed.