Early Time-Restricted Eating Improves Weight Loss While Preserving Muscle: An 8-Week Trial in Young Women

Area of Science:

• Nutrition Science
• Exercise Physiology
• Chronobiology

Background:

• Time-restricted eating (TRE) is a dietary strategy restricting daily food intake to a specific window.
• Its impact on resistance training (RT) adaptations, particularly comparing early (eTRE) versus delayed (dTRE) feeding windows, requires further investigation.
• Understanding optimal meal timing may enhance metabolic health and body composition.

Purpose of the Study:

• To compare the effects of early TRE (eTRE) and delayed TRE (dTRE) on body composition and RT adaptations in young women.
• To determine if eTRE or dTRE is superior for enhancing RT outcomes.
• To investigate the combined effects of TRE and RT on weight management and muscle function.

Main Methods:

• A 8-week randomized controlled trial involving 24 healthy young women with limited RT experience.
• Participants were assigned to eTRE (8 AM-2 PM), dTRE (12 PM-6 PM), or a control group (8 AM-8 PM).
• All groups performed standardized knee-supported push-ups three times per week; primary outcomes included body weight, muscle thickness (triceps brachii), and push-up endurance.

Main Results:

• The eTRE group exhibited significantly greater body weight reduction compared to dTRE and control groups.
• No significant differences were found between eTRE, dTRE, and control groups in muscle thickness or push-up endurance improvements.
• All groups demonstrated comparable increases in triceps brachii muscle thickness and push-up repetitions.

Conclusions:

• Early TRE (8 AM-2 PM) demonstrates superior efficacy for weight management when integrated with resistance training, outperforming delayed TRE (12 PM-6 PM).
• Both early and delayed TRE regimens yield similar benefits for muscle thickness and endurance adaptations alongside RT.
• Optimizing meal timing with circadian rhythms may be a viable strategy for weight loss while preserving muscular fitness.