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.

Keywords: obesity; overweight; time-restricted eating; weight loss.