Study Overview
overweight, sedentary behaviors
OBESE
Our study is the first RCT to assess the efficacy of an app-based lifestyle intervention on zBMI and lifestyle behaviors among overweight and obese Canadian youth that was mostly smartphone-based with no clinical in-person component. This study found no evidence of an effect on zBMI scores or any coprimary outcomes (PA, diet, and sedentary behaviors) for intervention participants compared with those of a control group over a 3-month period. Our primary analyses revealed no significant differences in zBMI or any of the health behaviors between the intervention and control groups. Secondary exploratory analyses revealed the following mixed findings: among waitlist control participants, zBMI, discretionary calories, and PA outside of school declined, whereas screen time increased after receiving app access compared with before receiving app access. Overall, we did not find evidence of additional benefits in terms of giving participants access to a live coach, and app use did not modify any outcomes among adolescents in the intervention group.