Despite widespread use of smartphones and wearables, we have limited evidence that they aid weight loss or lifestyle. Here, we report results of a 6-month RCT of our smartphone app-based lifestyle intervention vs. standard of care (in-person weight management visits at 0, 3, and 6 months) in a cohort of overweight or obese subjects. The app downloads objective data of daily weights from smartscales and physical activity from 3-axis accelerometers. The technology allows peer social networking and remote professional coaching employing behavior modification techniques delivered via group and private messaging, emoticons, shared activity and weight data, shared photographs of meals, and a virtual reward system for behavior modification. Intervention group: n=13, 85% F, age 39.5 ± 3.71 y, initial weight 94.3 ± 3.42 kg, BMI 34.5 ± 1.3 kg/m2. Control group: n=15, 86% F, age 45.1 ± 3.31 y, initial weight 92.3 ± 4.37 kg, BMI 33.8 ± 1.kg/m2 (means ± SE). We found a clinically and statistically significant weight difference of -4.2 ± 2.0 kg (95% CI -8.3 to -0.02 p=0.0488) after 6 months of our smartphone app-based lifestyle intervention (prespecified primary outcome, intervention vs. control). In the intervention group, weight change was -7.2 ± 1.8 kg (95% CI -11.1 to -3.3, p = 0.0017); % weight change was -7.9% ± 2.2% (95% CI -12.6 to -3.2, p=0.0031). Weight change significantly associated with median step counts (Pearson’s correlation coefficient r=-0.61, p=0.027), numbers of text messages from each subject (r=-0.83, p=0.0005), and numbers of diet photos shared (r =-0.83 p=0.0005). Our app-based lifestyle intervention met the prespecified primary outcome of clinically meaningful and statistically significant weight loss at 6 months over control. The strongest correlations with weight loss in the intervention group were physical activity (step counts) and subjects’ engagement in behavior modification coaching (messages and diet photos). Disclosure C. Vaz: None. A.G. Suthar: None. B.T. Pousti: None. S.M. Aye: None. K. Williams: Stock/Shareholder; Self; Hygieia, Gemphire, Inc.. Advisory Panel; Self; Gemphire, Inc.. H. Zhao: None.
Read full abstract