Metabolic Efficacy of Time-Restricted Eating in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract Context Time-restricted eating (TRE), which restricts food intake to a limited duration of the day, is a key regimen of intermittent fasting. Objective The aim of our study was to provide an up-to-date meta-analysis and systematic review to evaluate the efficacy of TRE on weight loss and other metabolic-related parameters in adults. Methods We searched PubMed, EMBASE, and the Cochrane Library for relevant studies published before February 26, 2022. Study duration of TRE was at least 4 weeks. Body weight and other metabolic-related continuous parameters were described as weighted mean difference (WMD) with 95% CI. Results Seventeen randomized controlled trials involving 899 participants were analyzed. The pooled meta-analysis has shown that TRE contributed to a significant decrease in body weight with a WMD of −1.60 kg (95% CI −2.27 to −0.93) and fat mass with WMD −1.48 kg (95% CI −1.59 to −1.38). Subgroup analysis showed that TRE could reduce body weight and fat mass especially in overweight participants with WMD −1.43 kg (95% CI −2.05 to −0.81) and −1.56 kg (95% CI −1.67 to −1.44), respectively. TRE also showed beneficial effects on the lipid spectrum in overweight participants, including decreased levels of triglyceride (WMD −12.71 mg/dL, 95% CI −24.9 to −0.52), total cholesterol (WMD −6.45 mg/dL, 95% CI −7.40 to −5.49), and low-density lipoprotein cholesterol (WMD −7.0 mg/dL, 95% CI −9.74 to −4.25). However, compared with control, TRE had no significant effects on waist circumference, body mass index, glycosylated hemoglobin, or blood pressure. Conclusion This updated meta-analysis found that TRE may be an effective approach to improve the metabolic state of nonobese subjects, especially in overweight participants.