The Study
Effect of an acute prolonged overnight fast on skeletal muscle insulin and anabolic sensitivity in healthy men.
This study tested whether fasting longer overnight helps your muscles use protein better, and it found that it doesn't — at least not in young, healthy guys. It's like comparing two different breakfasts to see which one makes your muscles stronger, and the results showed no real difference.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if sleeping 16 hours instead of 10 makes your muscles better at using protein from your next meal.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 565 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1No, the change in insulin didn't help muscles use protein better — longer fasting didn't improve muscle building from food.
- 2After 16 hours of fasting, insulin dropped by 7.4 units, but muscle protein growth from food stayed the same as after 10 hours of fasting.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of nutrition
Year
2026
Authors
Joanne Mallinson, M. Keeton, Aline Nixon, A. Sheth, Robert Jones, Pardeep Pabla, J. Senden, Luc J. C. van Loon, K. Tsintzas
Related Content
Claims (5)
In healthy young men, skipping food for 16 hours overnight does not increase how well their muscles respond to protein intake, even though insulin levels drop after eating.
In healthy young adult men, a 16-hour overnight fast does not increase how quickly amino acids from food are added to muscle protein, even though insulin levels drop slightly after eating.
In healthy young adult men, skipping food for 16 hours overnight lowers the rise in blood insulin after eating by about 7.4 mIU/L compared to skipping food for 10 hours, and does not change how muscles take up amino acids or process glucose.
In healthy young men, fasting for 16 hours overnight does not increase the uptake of branched-chain amino acids or the disposal of glucose after eating a mixed meal compared to fasting for 10 hours.
This study's results apply only to nine healthy young men and cannot be applied to older adults, women, or people with insulin resistance.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.