Background and Aims Bariatric and metabolic surgery is the most effective treatment modality for moderate to severe obesity and pathological obesity, but there are strict surgical indications for bariatric surgery, and a feasible and effective approach for weight loss is also needed for some patients who do not meet the surgical criteria. The risk of bariatric surgery is significantly increased for super-obese patients. Such patients also need an acceptable and efficacious approach to lose weight before surgery to reduce the risk of surgery. Time-restricted eating (TRE) is a new strategy for weight loss and treatment of metabolic diseases based on circadian rhythm, which is expected to be a powerful supplement to bariatric surgery. However, there is no comprehensive assessment of the impact of TRE on weight, body composition, and metabolism. Therefore, this study was conducted to evaluate the effects of TRE on weight, body composition, and body metabolic parameters through systematic review and Meta-analysis to provide evidence-based medical information for clinical decision-making.Methods The randomized controlled studies regarding the effects of TRE on body weight, body composition, and body metabolism were searched in the PubMed, Web of Science, EMBASE, CNKI, and Wanfang databases. The retrieval time was from the inception of the database to April 1, 2022. After the literature screening, data extraction, and assessment of the bias risk of the included studies by two independent researchers, Meta-analysis was performed using Stata 17.0 software.Results A total of 14 studies with 587 subjects were included. The results of the Meta-analysis showed that in the individuals after TRE intervention versus those with a calorically unrestricted normal diet, the weight (WMD=-2.40, 95% CI=-3.52--1.29, P<0.001) and fat mass (WMD=-1.48, 95% CI=-2.26--0.69, P<0.001) were significantly reduced, and the concentration of triglyceride (WMD=-8.42 mg/dL, 95% CI=-13.69--3.15, P=0.002) was decreased; however, there were no significant differences in fat-free mass, fasting glucose, systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein, and low-density lipoprotein (all P>0.05).Conclusion TRE is an effective weight-loss treatment, which yields significant weight loss with a main effect on fat mass reduction and no significant influence on fat-free mass, and meanwhile is helpful for improving the triglyceride levels. It may be used as a powerful supplement to bariatric surgery. However, the above conclusion still needs to be verified by more high-quality studies due to the limitations in the number and quality of the included studies.