Optimizing an extended care intervention to promote weight loss maintenance - PROJECT SUMMARY / ABSTRACT Although behavioral interventions for obesity achieve clinically meaningful weight loss, post-treatment weight regain remains a pernicious challenge. Extended care interventions that include evidence-based behavioral strategies can improve weight loss maintenance (WLM), but many of these strategies require significant effort and resources that can hinder treatment adherence. Thus, strategies are needed that increase individuals' capacity (i.e., resources, abilities, and readiness) to consistently engage in WLM behaviors while minimizing the effort required of treatment. However, the most effective strategies for this are unknown. By leveraging the multiphase optimization strategy framework and a factorial experimental design, this application proposes an extended care optimization trial to efficiently test four “minimally disruptive” intervention components (i.e., effective treatments designed to enhance capacity with limited participant burden). Following an initial 6-month weight loss phase, participants achieving 5% weight loss (N=272) will be randomized into a 12-month trial to receive 0-4 of the intervention components in addition to a core, extended care program. The minimally disruptive components include: 1) reduced food variety (i.e., limiting number of energy-dense dinners and snacks), 2) home-based resistance training (i.e., low-dose prescriptions performed x2/week), 3) buddy training and support (i.e., leveraging individuals from existing social networks to provide support), and 4) acceptance and commitment therapy (ACT) workshops (i.e., condensed ACT skills training). These components have empirical support for weight management but are distinct from conventional behavioral WLM recommendations. Further, all are designed to enhance individuals' capacity with limited burden. The primary outcome is WLM between randomization and month 12. An optimized intervention package will be assembled based on the combination of minimally disruptive components most effective for WLM. In addition, hypothesized mediators of each treatment component and participant characteristics moderating treatment response will be examined. This project will lead to an optimized WLM intervention package that can be evaluated in a subsequent confirmatory randomized controlled trial. This line of research can inform best practices for the provision of WLM interventions, improve long-term outcomes for individuals, and strengthen the overall public health impact of available weight management interventions for disease prevention and management.
