Perspectives on the Form, Magnitude, Certainty, Target, and Frequency of Financial Incentives in a Weight Loss Program.

Purpose: Financial incentives are a promising approach to enhance weight loss outcomes; however, little guidance exists on the optimal incentive structure.

Design: Mixed methods.

Setting: An online weight management trial, combining outcome (i.e., weight loss) and behavioral (i.e., self-weighing, dietary self-monitoring, and steps) incentives over 12 months (up to $665).

Subjects: 116 participants who completed the incentive preference assessment at the 18-month follow-up visit.

Method: Response distributions on the form, magnitude, certainty, and target of the incentives and content analysis of the qualitative responses.

Results: Nearly all (96.6%) participants indicated they liked receiving electronic Amazon gift cards, more so than the alternatives presented. Most participants (81.0%) thought they would have lost a similar amount of weight if the incentives were smaller. Few (18.1%) indicated they would have preferred a lottery structure, but 50.8% indicated the variable incentive schedule was beneficial during the maintenance period. Most (77.6%) felt incentives were most helpful when starting to lose weight. In both phases, most participants (85.3% and 72.4%, respectively) indicated appropriate behaviors were incentivized. Participants had mixed views on whether outcome or behavioral incentives were most motivating.

Conclusion: There was notable variation in preferences for the magnitude, duration, and timing of incentives; it will be important to examine in future research whether incentive design should be tailored to individual preferences.