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

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

Mixed methods.

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).

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

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

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.

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.