A randomized controlled trial evaluated the effectiveness of financial incentives based on behavioral economics in promoting weight loss. The study involved 57 obese or overweight adults (BMI 30-40) at the Philadelphia Veterans Affairs Medical Center. Participants were randomly assigned to either usual care (monthly weigh-ins) or one of two incentive groups: a deposit contract (participants risked their own money if they failed to lose weight) or a lottery (participants had a chance to win small or large rewards based on weight loss). All participants aimed to lose 16 pounds over 16 weeks. Both incentive groups achieved significantly more weight loss than the control group. The lottery group lost 13.1 pounds, and the deposit contract group lost 14.0 pounds, compared to 3.9 pounds in the control group. Over 47% of deposit contract participants and 52.6% of lottery participants met the 16-pound goal, compared to 10.5% in the control group. By the end of 7 months, weight was regained, but incentive participants still weighed significantly less than at the start of the study. The study found that financial incentives based on behavioral economics can effectively promote weight loss. Incentive-based approaches may help reduce obesity-related illnesses. The results suggest that such interventions can be effective in achieving significant weight loss, though long-term maintenance remains a challenge. The study highlights the potential of behavioral economics in designing effective weight loss interventions. The use of deposit contracts and lotteries leveraged concepts such as loss aversion and the anticipation of regret to motivate participants. The study also noted that while weight was regained over time, incentive participants maintained lower weights compared to the control group. The findings support the use of financial incentives in weight management programs.A randomized controlled trial evaluated the effectiveness of financial incentives based on behavioral economics in promoting weight loss. The study involved 57 obese or overweight adults (BMI 30-40) at the Philadelphia Veterans Affairs Medical Center. Participants were randomly assigned to either usual care (monthly weigh-ins) or one of two incentive groups: a deposit contract (participants risked their own money if they failed to lose weight) or a lottery (participants had a chance to win small or large rewards based on weight loss). All participants aimed to lose 16 pounds over 16 weeks. Both incentive groups achieved significantly more weight loss than the control group. The lottery group lost 13.1 pounds, and the deposit contract group lost 14.0 pounds, compared to 3.9 pounds in the control group. Over 47% of deposit contract participants and 52.6% of lottery participants met the 16-pound goal, compared to 10.5% in the control group. By the end of 7 months, weight was regained, but incentive participants still weighed significantly less than at the start of the study. The study found that financial incentives based on behavioral economics can effectively promote weight loss. Incentive-based approaches may help reduce obesity-related illnesses. The results suggest that such interventions can be effective in achieving significant weight loss, though long-term maintenance remains a challenge. The study highlights the potential of behavioral economics in designing effective weight loss interventions. The use of deposit contracts and lotteries leveraged concepts such as loss aversion and the anticipation of regret to motivate participants. The study also noted that while weight was regained over time, incentive participants maintained lower weights compared to the control group. The findings support the use of financial incentives in weight management programs.