ObjectiveTo systematically review the effect of intermittent fasting on type 2 diabetes mellitus. MethodsThe CNKI, WanFang Data, VIP, CBM, PubMed, Web of Science, The Cochrane Library and EMbase databases were electronically searched to collect randomized controlled trials (RCTs) on intermittent fasting intervention in the treatment of type 2 diabetes mellitus from inception to April 2022. Two reviewers independently screened the literature, extracted data, and evaluated the risk of bias of the included studies. The RevMan 5.4 software and Stata 17.0 software were used for meta-analysis. ResultsA total of 17 RCTs comprising 1 428 patients with type 2 diabetes mellitus were included. The results of meta-analysis showed that intermittent fasting improved body weight (WMD=−2.84, 95%CI −3.79 to −1.88, P<0.05), body mass index (BMI) (WMD=−1.07, 95%CI −1.52 to −0.61, P<0.05), glycosylated hemoglobin levels (SMD=−0.78, 95%CI −1.19 to −0.38, P<0.05), and fasting glucose levels (SMD=−0.65, 95%CI −1.01 to −0.3, P<0.05). ConclusionThe current evidence suggests that intermittent fasting improves body weight, BMI, glycated hemoglobin, and fasting blood glucose levels in patients with type 2 diabetes. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.