Exploring Optimal Treatment Components for Contactless Online Group-based Behavioral Weight Loss Program

All participants will receive the same online group-based weight loss program, a lifestyle intervention which we have demonstrated to be effective in the past. The 16-session, goal-driven behavioral weight control program offers weekly interactive modules that provide evidence-based health education on caloric balance and physical activity increases, with a goal of fostering changes in diet and exercise habits and producing weight losses of 5-10%. The intervention is based on social cognitive theory and uses a self-regulation approach to learning new lifestyle habits that can produce and maintain weight loss. Participants in all study arms will be provided with the same calorie and physical activity goals, and all participants will be asked to self-monitor their dietary intake and physical activity daily using an app on their smart phone. They will also be asked to weigh themselves daily, consistent with research indicating that daily weighing is associated with greater weight loss and participants will be provided with a Bluetooth-enabled "smart scale" that will communicate weight to the password-protected study website (visible to only the participant and study staff). The study website also provides the dynamic programmatic content, real time graphic feedback from self-monitoring (for each individual participant) and a study group discussion board for asynchronous group interactions and social support. The website includes the core aspects of the behavioral program and is to be provided to all participants.