Efficacy of environmental and acceptance-based enhancements to behavioral weight loss treatment: The ENACT trial

Abstract

Objective: This study was designed to compare weight loss through a traditional behavioral treatment (BT) approach that integrated skills for managing the obesogenic food environment (BT + E) with an approach that integrated environmental and acceptance-based skills (BT + EA). Moderators were examined as an exploratory aim. Methods: Adults (N = 283) were randomly assigned to treatment condition and provided with 26 group-based sessions over the course of 12 months. Weight was measured in the clinic at months 0, 6, and 12. Results: Change in weight over time did not significantly differ by condition. However, race significantly moderated the effect of condition on weight loss (P = 0.04), such that African-American participants lost less weight than non-Hispanic white participants in the BT (6.2% vs. 11.5%) and BT + E conditions (6.6% vs. 12.2%), but weight loss in these two groups was similar in the BT + EA condition (9.4% vs. 11.5%). Among African Americans, rates of achieving a clinically significant weight loss (i.e., > 5%) at 12 months were higher in BT + EA (80%) than BT (57%) or BT + E (48%) (P = 0.04). Conclusions: This innovative behavioral approach shows promise for treatment of African Americans, which is notable given the lack of progress to date addressing racial disparities in obesity intervention efficacy.