The Study
Early lean mass sparing effect of high-protein diet with excess leucine during long-term bed rest in women
This study showed that eating more protein with extra leucine helped women keep a little more muscle during the first two weeks of lying in bed — but after two months, both groups lost the same amount of muscle. So it’s like a short-term helper, not a long-term fix.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists gave some women a lot of extra protein with leucine while they lay in bed for 60 days, and others ate normal food, to see if the extra protein kept their muscles from shrinking.
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 562 / 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.
- 1Even though the extra protein helped at first, it didn't stop long-term muscle loss — so it's not enough to protect muscles during very long bed rest.
- 2For the first 15 days, the high-protein group lost 42% less muscle than the normal group.
- 3But after 60 days, both groups lost about 7% of their muscle.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Nutrition
Year
2022
Authors
P. Vinci, F. G. di Girolamo, A. Mangogna, F. Mearelli, A. Nunnari, N. Fiotti, M. Giordano, M. Bareille, G. Biolo
Related Content
Claims (7)
Consuming more protein results in greater gains in muscle mass and strength, and these gains are larger than the biological effects caused by activation of the mTOR pathway.
In healthy young women confined to bed rest for 60 days, those eating a diet with higher leucine (11.4 grams per day) had 2.5 times higher nitrogen balance in the first 15 days than those eating a standard diet with lower leucine (4.9 grams per day). After day 15, nitrogen balance was similar between the two groups.
In healthy young women confined to bed rest, a diet high in protein and leucine prevents muscle loss for the first 15 days, but after that, muscle loss proceeds at the same rate as with a standard protein diet.
In healthy young women confined to bed rest for 60 days, a diet with 11.4 grams of leucine daily reduced muscle loss by 42% in the first 15 days compared to a diet with 4.9 grams of leucine, but after 60 days, both diets led to the same total muscle loss of about 7%.
Among healthy young women confined to bed rest for 60 days, consuming a high-protein diet enriched with leucine did not reduce the loss of lean body mass compared to a control diet; both groups lost about 7% of their lean mass by the end of the period.
When total calorie intake is held constant, consuming more protein leads to greater muscle protein synthesis and less fat storage compared to consuming less protein.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.