Abstract 026: Adherence to Weight Loss Treatment Across Three Self-Monitoring Approaches and the Association with Weight Change

Abstract

Background: Adherence to the multiple components of a weight loss intervention is critical for successful short- and long-term outcomes. The purpose of this analysis was to determine if there was a difference in adherence to the five components of a standard behavioral weight loss intervention across three methods of self-monitoring diet and exercise in the 24-month SMART trial. Methods: In the SMART trial, 210 adults were randomized with equal allocation to one of three self-monitoring methods: 1) paper diary, 2) personal digital assistant (PDA) and 3) PDA + daily tailored feedback message (PDA+FB). The five treatment components included: attending group sessions; meeting the daily energy and fat goals and the weekly exercise goal; and self-monitoring eating and exercise behaviors. The cognitive-behavioral intervention was delivered in 39 group sessions over 18 months plus a maintenance session in the 21 st month. Attendance was measured objectively, whereas adherence to the other four components was based on self-report. Generalized mixed modeling was used to examine adherence over time and among the three groups as well as the association of adherence with weight loss. Results: The sample was predominantly female (84.8%), White (78.6%) and well educated (Mean±SD: 15.7±3.0 years). Mean BMI was 34.01±4.48 kg/m 2 . Initially, adherence was 100% for attendance, nearly 100% for self-monitoring, 60-80% for exercise, and less than 60% for the dietary goals. On average, participants in the PDA+FB and the PDA groups were more adherent to the treatment protocol than participants in the paper diary group for attendance (p<.05), self-monitoring (p<.05), energy goals (p<.05), fat goals (p=.07), and exercise goals (p<.05). Over time, there was a non-linear decline in adherence to all five components in all three groups. We also found a significant group by time interaction for adherence to each of the five components and a significant association between adherence to each component and weight change (ps<.0001). Conclusion: Compared to the paper diary group, adherence was usually higher in the groups using a PDA to self-monitor. Better weight loss was associated with better adherence to the five treatment components. These results suggest that using an electronic diary such as the PDA improves treatment adherence. The increasing availability of additional mobile devices for self-monitoring lifestyle and receiving real time feedback offers potential opportunity to build on these findings and possibly improve adherence and weight loss outcomes.