Effect of Time-Restricted Eating on Sleep Quality and Body Composition: A Systematic Review

Time-restricted eating (TRE) is a dietary approach that consolidates energy intake in a restricted period during the day. It is an alternative approach to weight loss and might be important to sleep quality.

To review the current literature related to the effects of TRE on sleep quality and body composition in adults.

A literature search of the PubMed, Scopus, Web of Science (Clarivate), and Biblioteca Virtual em Saúde/Bireme databases was carried out until May 2024.

Reviewed articles included clinical, interventional (controlled or uncontrolled) studies including individuals older than 18 years, with no gender restriction. The interventions had to control feeding time, body composition could be assessed by any validated method, and sleep could be assessed by polysomnography, actigraphy, and validated sleep assessment questionnaires.

Eleven studies were included in this systematic review. Study samples varied between 19 and 137 participants, with a predominance of female participants in 10 studies. Seven of the studies (58.3%) tested an intervention of 8 hours of TRE, with an intervention range of between 4 weeks and 12 months. All studies observed weight loss. Nine studies showed reductions in fat mass, including 2 studies that observed reductions in visceral fat mass. No studies, independently of weight loss or body composition changes, objectively observed changes in sleep duration after TRE interventions. However, in the subjective evaluation, 1 study found a reduction in sleep duration of 30 ± 13 minutes, an increase in latency of 7 ± 3 minutes, and a reduction in sleep efficiency of 2% ± 1% in the group treated with TRE compared with the control group.

Time-restricted eating seems to be effective in weight loss and fat mass reduction, but most studies found no effect on sleep parameters. There was a lack of standardized methods for sleep measurements in the reviewed studies. However, these results could provide valuable data for the design and formulation of new well-founded studies assessing sleep using objective methods and including different sleep parameters.

PROSPERO registration No. CRD42024524598.