The Effects of Time-Restricted Feeding versus a Normal Diet on Lean Body Mass in Active Individuals

Abstract

Introduction: Intermittent fasting (IF) is a popular dietary strategy for its health benefits and for weight management. Time-restricted feeding (TRF) is a common approach to IF, but its effects on lean mass (LM) have not been extensively studied in active individuals. All individuals must have participated in regular physical activity for at least six months to be considered in this analysis.Methods: A search of the current literature on TRF in active individuals was conducted. Studies were critically evaluated for quality and for clinical application.Results: Five studies fit established parameters, four of which studied TRF with a resistance training (RT) regimen, and one utilized aerobic training. TRF and normal diet (ND) groups had similar results for LM and RT outcomes when matched for calories. Results on fat mass loss and changes in body composition show mixed findings. Some data suggest a TRF is beneficial for improved aerobic performance.Conclusions: TRF does not appear to be superior to a ND for building or sustaining LM in active individuals, neither is it detrimental. Current literature points to overall energy and protein intake, rather than nutrient timing, as a key modulator of LM outcomes.