Effects of time-restricted eating on body composition, biomarkers of metabolism, inflammation, circadian system and oxidative stress in overweight and obesity: an exploratory review

Abstract

Obesity is a chronic, complex and multi-factorial condition with an increasing prevalenceworldwide. Irregular eating schedules might be a contributing factor to these numbers throughthe dysregulation of the circadian system. Time-restricted eating (TRE), an approach that limitseating windows, has been studied as a strategy to treat obesity, aligning eating occasions withmetabolic circadian rhythms. This review aims to provide an overview of the impact of TREprotocols on metabolic, inflammatory, oxidative stress and circadian rhythm biomarkers inpeople with overweight or obesity. Most studies report significant weight loss following TREprotocols. While glucose levels decreased in nearly all TRE interventions, only a few studiesdemonstrated statistically significant differences when compared to the control groups. Thefindings for c-reactive protein and TNF-alpha were inconsistent, with limited significantdifferences. Changes in lipid profile changes were variable and generally did not reach statisticalsignificance. Both 4-hour and 6-hour TRE interventions significantly reduced 8-isoprostanelevels. Additionally, TRE significantly altered clock gene expression, as well as that of genesassociated with metabolic regulation in subcutaneous adipose tissue. While the evidence is stillinconsistent, limiting eating to a consistent daily window of 8 to 12 h can improve insulinsensitivity, reduce blood glucose, cholesterol and triglyceride levels and promote weight loss.These effects are likely attributable to both direct metabolic impacts and indirect benefits fromweight loss and improved dietary habits. However, data on circadian, inflammatory and specificmetabolic biomarkers remain scarce and occasionally contradictory, highlighting the need forfurther research on these interventions.