Objective To evaluate the effects of incretin-based therapies on body weight as the primary outcome, as well as on body mass index (BMI) and waist circumference (WC) as secondary outcomes. Methods Databases including Medline, Embase, the Cochrane Library, and clinicaltrials.gov (www. clinicaltrials.gov ) were searched for randomized controlled trials (RCTs). Standard pairwise meta-analysis and network meta-analysis (NMA) were both carried out. The risk of bias (ROB) tool recommended by the Cochrane handbook was used to assess the quality of studies. Subgroup analysis, sensitivity analysis, meta-regression, and quality evaluation based on the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) were also performed. Results A total of 292 trials were included in this study. Compared with placebo, dipeptidyl-peptidase IV inhibitors (DPP-4Is) increased weight slightly by 0.31 kg [95% confidence interval (CI): 0.05, 0.58] and had negligible effects on BMI and WC. Compared with placebo, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) lowered weight, BMI, and WC by -1.34 kg (95% CI: -1.60, -1.09), -1.10 kg/m(2) (95% CI: -1.42, -0.78), and -1.28 cm (95% CI: -1.69, -0.86), respectively. Conclusion GLP-1 RAs were more effective than DPP-4Is in lowering the three indicators. Overall, the effects of GLP-1 RAs on weight, BMI, and WC were favorable.