Mobile weight self-monitoring adherence and eating behavior changes: A secondary analysis of a 12-month RCT.

Background: Mobile health behavior change support systems (mHBCSS) have been shown effective in weight management by promoting self-monitoring, a persuasive strategy that enhances engagement and supports healthier behaviors. Daily weight tracking supports weight loss but may increase the risk of disordered eating, particularly in individuals with obesity. Objective: To assess the 12-month impact of weight self-monitoring on eating behaviors among individuals with obesity using a mHBCSS. Methods: We analyzed data from 98 participants in a 12-month randomized controlled trial using a mHBCSS. Participants were grouped into "continuous self-monitors" (monitored ≥6 months) and "non-continuous self-monitors." Outcomes included binge eating scale (BES), cognitive restraint (CR), emotional eating (EE), and uncontrolled eating (UE). Between-group differences at each time point (0, 6 and 12 months) were evaluated with the Mann-Whitney U test. Within-group changes over time were analyzed using the Friedman test, followed by Wilcoxon signed-rank tests for pairwise comparisons. Results: Continuous self-monitors exhibited significantly higher CR at six months (p < 0.01) and lower BES across all time points (p < 0.05, < 0.01, < 0.001) when compared to non-continuous self-monitors. Within-group analysis revealed that in the continuous self-monitor group, BES, UE and EE showed significant reductions over time (p < 0.0001), while CR increased (p < 0.0001). Conclusion: Continuous self-monitoring appears to support sustained improvements in eating behaviors, including increased CR and reductions in disordered eating patterns over time. These findings highlight the potential of tailored mHBCSS, using evidence-based strategies, personalized feedback, and subtle reminders, to enhance engagement, promote healthier habits, and reduce the risk of disordered eating.