ObjectiveTo systematically review the efficacy of mobile health (mHealth) apps on weight loss.MethodsWeb of Science, PubMed, CNKI, WanFang Data and CBM databases were electronically searched to collect randomized controlled trials (RCTs) on the efficacy of mHealth APPs on weight loss from inception to October 18, 2019. Two reviewers independently screened literature, extracted data and assessed risk of bias of included studies. Meta-analysis was then performed using RevMan 5.3 software.ResultsA total of 12 RCTs involving 1 074 patients were included. The results of meta-analysis showed that the apps group was superior to the control group in body weight (MD=−1.88, 95%CI −3.23 to −0.53, P=0.006). There was a decreasing trend of body mass index (BMI) in apps group (MD=−0.55, 95%CI −1.09 to 0.00, P=0.05).ConclusionsCurrent evidence shows that mHealth app can increase the efficacy of weight loss. Due to limited quality and quantity of the included studies, more highquality studies are required to verify above conclusions.