Smartphone app-based interventions targeting physical activity for weight management: A meta-analysis of randomized controlled trials

Background: Being overweight and obese are major public health challenges worldwide. Smartphone apps are an innovative platform to deliver physical activity modifications for weight management. This study aimed to explore the efficacy of smartphone app-based interventions targeting physical activity for obesity-related outcomes and compare the efficacy among behavioral change techniques. Methods: Five online databases were searched for randomized controlled trials in September 30, 2021. Hedges' g was used to compute effect sizes. The random effect models were conducted for all analyses. Results: In total, 12 trials were selected for qualitative and quantitative syntheses. Smartphone app-based interventions exerted small-to-moderate effects on body weight, body mass index, and body fat percentage. The meta-regression found that the older age of participants and a longer duration of the intervention increased the effect. Subgroup analyses found that the interventions were more effective on body weight among participants with a disease or disability, and on body mass index in participants who were obese or overweight. Apps with features such as reminders, self-reporting, and a health coach used as behavioral change techniques were more effective. Conclusion: Smartphone apps are an effective and feasible strategy for physical activity modification using behavioral change techniques. Smartphone app-based interventions can promote physical activity for weight management.