Meta-analysis of smartphone applications targeting eating behaviour for weight loss

Smartphone applications ("apps") could be safe, cost-effective, and accessible tools for weight loss. Numerous weight-loss apps are available, but their longer-term efficacy is unclear. We conducted a meta-analysis of randomised controlled trials of weight loss apps that target eating behaviour in adults. We (a) compared the amount of weight lost in app-based interventions to other interventions and waitlists, and (b) estimated mean weight loss at six months and longer in app-based interventions. A database search identified 23 studies matching our criteria. We used three-level meta-analytic models and applied various bias-correction methods. More weight was lost in app-based interventions than on waitlists (mean difference 2.07 kg) and in non-app-based interventions (mean difference 1.64 kg) at six months. In app-based interventions, weight loss estimates ranged from 0.63 to 3.87 kg at six months; mean weight loss was 2.64 kg at longer follow-ups. We found no moderating effects of factors such as calorie counting, social support, involvement of medical workers, or automatic feedback reports. Smartphone apps could be cost-effective tools to facilitate weight loss and help maintain weight loss after surgery or drug treatments, but more studies on apps' long-term effectiveness are needed.