Digital self‐monitoring: Does adherence or association with outcomes differ by self‐monitoring target?

OBJECTIVE: Digital self‐monitoring of eating, physical activity, and weight is increasingly prescribed in behavioural weight loss programmes. This study determined if adherence rates or associations with outcomes differed according to self‐monitoring target (ie, self‐monitoring of eating versus physical activity versus weight). METHODS: Participants in a 3‐month, group‐based weight loss programme were instructed to use an app to record food intake, wear a physical activity sensor, and use a wireless body weight scale. At post‐treatment, weight loss was measured in clinic and moderate‐to‐vigorous physical activity (MVPA) was measured by research‐grade accelerometer. RESULTS: Adherence to self‐monitoring decreased significantly over time for eating and weight but not physical activity. Overall, adherence to self‐monitoring of weight was lower than that of eating or physical activity. Greater adherence to self‐monitoring of eating, physical activity, and weight each predicted greater weight loss. Only greater adherence to self‐monitoring of eating was associated with greater bouted minutes of MVPA. CONCLUSIONS: Findings from this study suggest that self‐monitoring should be considered a target‐specific behaviour rather than a unitary construct when conceptualizing adherence and association with treatment outcomes.