Pilot of a Micro-Randomized Factorial Trial of Self-Monitoring Feedback in a Behavioral Weight Loss Intervention

The provision of self-monitoring feedback has been demonstrated to improve weight loss program outcomes; however, there is little evidence to support how this feedback should be delivered. Micro-randomized factorial trial designs can examine the proximal impact of intervention components, but their feasibility and acceptability in the context of behavioral weight management programs remain unknown.

The current pilot study evaluated the feasibility and acceptability of procedures for a micro-randomized factorial trial designed to optimize the provision of self-monitoring feedback messages in behavioral weight management programs. Adults with obesity were provided with an initial Weight Loss 101 education session and asked to self-monitor dietary intake, physical activity, and weight daily (using an app, activity monitor, and e-scale). They were then randomized each week for 16 weeks (using a 2⁴ factorial design) to receive or not receive each of four feedback components (feedback on calorie goal attainment, diet quality, physical activity goal attainment, or to support goal setting) sent via text with a link to an individualized website.

Of the 28 participants enrolled (86% women; mean ± SD BMI = 37.2 ± 6.6 kg/m²), most (93%) completed the study; participants self-monitored dietary intake, physical activity, and weight on 65%, 87%, and 76% of possible days, respectively. Most weekly feedback messages were viewed (92%); 63% were rated and 90% of rated messages were deemed helpful.

Trial procedures were both feasible and acceptable among adults with obesity. Findings can inform the design of future micro-randomized factorial trials.