Small Monetary Incentives Lead to Greater Adherence in a Weight Loss Program

Abstract

Purpose: Understand how weekly monetary incentives for dietary tracking and/or weight loss impact 6-month weight loss behavioral adherence.

Design: Secondary analysis of participants randomized to one of four conditions in a behavioral weight loss intervention: incentives for dietary tracking, incentives for weight loss, both, or none.

Setting: Participants were asked to self-weigh at least twice weekly, log food and drink in a mobile application five days weekly, and attend bi-weekly, group-based classes.

Sample: Data from (n = 91) adults with obesity who completed a 24-week behavioral weight loss intervention of whom 88% were female and 74% Non-Hispanic White, were analyzed.

Measures: Non-adherence to weight and dietary self-monitoring was defined as the second week of not meeting criteria. Class attendance was also tracked.

Analysis: Kaplan-Meier analyses were used to examine differences across the four conditions.

Results: Participants incentivized for dietary self-monitoring had an average 15.8 weeks (SE:1.2) until the first non-adherent week compared to 5.9 weeks (SE:0.8) for those not incentivized for dietary self-monitoring (P < .01). Those incentivized for weight loss had an average 18.0 weeks (SE:1.02) of self-weighing until the first non-adherent week compared to 13.5 weeks (SE:1.3) for those not incentivized for weight loss (P = .02). No difference in class attendance was observed.

Conclusions: Incentivizing behaviors associated with weight loss improved adherence to those behaviors and does not appear to spill over to non-incentivized behaviors.

Keywords: incentives; interventions; motivation; strategies; weight control.

Figure 1.

A-D: Nonadherence to dietary self-monitoring over the 24-week intervention by treatment group* *Note: Each line represents one participant with study IDs presented on the right of each figure. Gray is nonadherent; black is adherent. Group A received incentives for both dietary self-monitoring and weight loss, Group B received incentives for dietary self-monitoring only, Group C received incentives for weight loss only, and Group D did not receive incentives.

Figure 2.

Kaplan-Meier survival curves for dietary self-monitoring. Note. Groups A and B were incentivized for dietary self-monitoring, whereas groups C and D were not.

Figure 3.

A-D: Nonadherence to self-weighing over the 24-week intervention by treatment group* *Note. Each line represents one participant with study IDs presented on the right of each figure. Gray is nonadherent; black is adherent. Group A received incentives for both dietary self-monitoring and weight loss, Group B received incentives for dietary self-monitoring only, Group C received incentives for weight loss only, and Group D did not receive incentives.

Figure 4.

Kaplan-Meier survival curves for self-weighing. Note. Groups A and C were incentivized for weight loss, whereas groups B and D were not.