The study will evaluate the effectiveness of financial incentives in improving maintenance of weight loss. The investigators propose a 2-arm randomized controlled trial in which 258 participants who lose at least 5 kgs in a weight loss program will be randomized to one of the following: 1) daily weigh-ins and weekly feedback, 2) daily weigh-ins,weekly feedback, and a weekly escalating lottery-based financial incentive.
Study participants will be obese volunteers recruited from a major community-based weight loss program (Weight Watchers), who have lost at least 5kg during the 4-6 months prior to enrolling in the study. Upon enrollment, these participants will have an active online membership with Weight Watchers. Among these participants, the following will be assessed: 1. Assess the effectiveness of escalating lottery rewards, relative to the control group, on maintenance of weight loss over the ensuing 6 months (Phase I); 2.The degree to which weight loss is maintained in the intervention group relative to usual care during the 6 months following the cessation of the interventions (Phase II).
During Phase I, incentives will be provided to some study participants (escalating lottery arm) for the first 6 months and participants will be followed for 6 more months to examine effects following cessation of incentives.