Comparing Self-Monitoring Strategies for Weight Loss: Does Developing Mastery Before Diet Tracking Enhance Engagement?

Self-monitoring of dietary intake is a valuable component of behavioral weight loss treatment but engagement in self-monitoring declines quickly, resulting in suboptimal treatment outcomes. This dissertation examined a novel weight loss intervention that aims to lessen the decline in self-monitoring engagement by building mastery, self-efficacy, and self-regulatory skills—key constructs of behavior change—prior to self-monitoring diet. GoalTracker was a randomized controlled trial among 105 adults with overweight or obesity comparing three standalone 12-week weight loss interventions: (1) a Simultaneous arm with concurrent self-monitoring of weight and diet each day, along with weekly lessons, action plans, and tailored feedback via email; (2) a Sequential arm with the same components but that tracked only weight through week 4, then added diet tracking; and (3) an App-Only arm that only tracked diet, and did not receive additional behavior change components. All groups used the commercial app MyFitnessPal for self-monitoring and received a tailored calorie goal and a goal to lose 5% of initial weight by 12 weeks. Paper one examined the impact of the intervention on weight change and self-monitoring engagement (Aims 1-3) and found significant weight loss and engagement for all treatment arms, with no differences between arms. Paper two examined the relation between consistent self-monitoring and weight loss (Aim 4), revealing that consistent trackers lost significantly more weight than others. Lastly, paper three examined whether early weight loss predicts future engagement and weight loss success (Aim 5), which was supported. Regardless of the order in which diet is tracked, using tailored goals and a commercial app can produce clinically significant weight loss. Consistent self-monitoring and early weight loss should be emphasized. Standalone digital health treatments may be a viable option for those looking for a lower intensity approach.