Time-Restricted Eating versus Calorie Restriction for the Management of Metabolic Syndrome and Implications for Physical Performance: A Systematic Review and Meta-analysis

Background: Metabolic syndrome is a growing global health concern associated with an increased risk of cardiovascular disease and type 2 diabetes. Among various dietary interventions, Time-Restricted Eating (TRE) and Calorie Restriction (CR) are two prominent strategies used to manage metabolic parameters. Beyond their metabolic effects, emerging evidence suggests that TRE may also influence physical performance, body composition, and recovery, which are particularly relevant to athletes and physically active individuals.

Objective: To systematically compare the effects of Time-Restricted Eating versus Calorie Restriction on metabolic syndrome outcomes through a meta-analysis, while highlighting potential implications for physical performance.

Methods: A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, and Cochrane Library for studies published up to June 2025. Studies comparing TRE and CR in adults with metabolic syndrome were included. Data were extracted and analyzed using random-effects meta-analysis, with standardized mean difference (SMD) as the outcome measure. Heterogeneity, publication bias, and study quality were assessed.

Results: Nine studies met the inclusion criteria. The pooled estimate showed a significant benefit of TRE over CR for improving metabolic outcomes (SMD = −0.396; 95% CI: −0.479 to −0.313; p < 0.001). No significant heterogeneity was detected (I² = 0%, p = 1.000). In addition to metabolic improvements, findings from studies in athletes and active populations indicate that TRE may enhance endurance, support favorable body composition changes, and promote recovery without impairing performance.

Conclusion: Time-Restricted Eating appears more effective than traditional Calorie Restriction in improving metabolic parameters in individuals with metabolic syndrome, with added potential benefits for physical performance. TRE may represent a sustainable dietary strategy with both clinical and athletic applications. Further high-quality, long-term trials are warranted to validate these findings in diverse populations, including athletes.