16:8 eating while building muscle: it works, with trade-offs
Trained men and women in a calorie surplus gained lean mass just as well in an 8-hour eating window, with less fat. But training volume, energy and squat gains were lower.
What they studied
- Design
- Randomised trial
- People
- 17 well-trained adults (10 men, 7 women)
- Duration
- 8 weeks, 4 supervised resistance sessions a week
- Diet
- Both groups: 10% calorie surplus, 2.2 g/kg protein. 8-hour window vs normal eating (~13 h)
What they found
- Both groups gained strength, muscular endurance and fat-free mass (2.7 kg with the 8-hour window, 1.8 kg with normal eating).
- The normal-eating group gained 1.4 kg more fat.
- The 8-hour group did less total training volume (6,960 vs 7,334 reps) and rated their daily energy lower.
- Squat 1RM gains were 4 kg smaller with the 8-hour window. Mood and sleep did not change.
How strong is the evidence
RCT · n=17
What this design cannot tell us:
- Only 17 people over 8 weeks.
- Everyone was well trained and eating in a surplus with high protein; results may differ in a deficit.
What it means for your training
- Time-restricted eating fits a muscle-building phase if calories and protein are high enough.
- If top-end strength is the goal, a wider eating window may serve you better.
Our summary of the published abstract. Read the original paper for full details.