Microrandomized Trial to Optimize Use of Burden-reducing Self-monitoring Approaches in Behavioral Obesity Treatment

This clinical trial is focused on testing dietary self-monitoring strategies used in behavioral obesity treatment. The goal is to determine which self-monitoring strategies are most useful for whom, at which points in treatment, and under what circumstances. Researchers will provide a 24-week online behavioral obesity treatment program, and will randomize participants to use one of 5 dietary self-monitoring strategies every two weeks. The five strategies include: recording all food and drink consumed and corresponding energy intake (i.e., "calories") on 7 days per week; recording all food and drink consumed and corresponding energy intake (i.e., "calories") on 3 days per week; self-monitoring of dietary lapses (i.e. any eating/drinking likely to cause weight gain or put weight loss at risk); smartwatch-based monitoring of energy intake (i.e., "calories"); and self-monitoring of body weight only via smart scale. Participants will: * Follow a 24-week online program for weight loss and health improvement * Use the assigned self-monitoring strategy every two weeks * Meet with the researchers periodically via online video call and provide research data by answering questions via periodic online surveys.