Enhancing Weight Loss Programs: A Meta-Analysis of Financial Incentives and Behavior Change Techniques.

Obesity is a risk factor for chronic illness. Financial incentives contingent on behaviors or outcomes related to weight loss can promote weight loss efforts. This meta-analysis examines the added effect of financial incentives for weight loss in health behavior change interventions, both short- and long-term, in adults. Additionally, subgroup analyses explored incentive targets (physiological outcomes, lifestyle behaviors, process behaviors, or multiple targets) and types of behavior change techniques (BCTs; interactive or passive) as moderators. Seven databases were systematically searched for (quasi-)randomized control trial studies. The meta-analysis included 29 studies with incentive and control conditions, 2396 adults in control and 3397 in incentive conditions. Using a random-effects model, results showed a small, significant, positive effect of incentives on weight loss during the incentive phase (i.e., short-term; 51 comparisons; SMD = 0.180, p < 0.001) but not in the post-incentive phase (i.e., long-term, after incentive removal; 23 comparisons; SMD = 0.032, p = 0.432). However, limited studies reported post-incentive data. In the incentive phase, subgroup analyses showed that incentivizing multiple targets and physiological outcomes has a larger effect than incentivizing lifestyle and process behaviors. Subgroup analyses showed no significant effect of type of BCTs. However, in the incentive phase, the within-group analysis showed that combining incentives with interactive BCTs had a significant effect while passive BCTs did not. Suggesting that combining incentives only with passive BCTs may not be sufficient to achieve weight loss, given its complexity. In conclusion, these findings suggest that financial incentive interventions are effective on short-term weight loss, especially when incentivizing multiple targets or physiological outcomes.