The Study
Dietary protein intake does not modulate daily myofibrillar protein synthesis rates or loss of muscle mass and function during short-term immobilization in young men: a randomized controlled trial.
This study tested if eating more or less protein changes how fast your muscles shrink when you can't use them for a few days. They gave different groups different amounts of protein and measured muscle changes — so we can say protein intake didn't make a difference in this case.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Scientists tested if eating more protein helps keep your muscles from shrinking when you have to keep one leg still for a few days.
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 560 / 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.
- 1Yes — even if you eat more protein, you still lose muscle quickly when you stop using your leg, at least in the short term.
- 2When one leg was kept still for 3 days, muscle size dropped by 2–2.7% and muscle protein production fell by 26–30%.
- 3This happened the same amount whether people ate very little, some, or a lot of protein.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The American journal of clinical nutrition
Year
2020
Authors
Sean P. Kilroe, J. Fulford, S. Jackman, A. Holwerda, A. Gijsen, Luc J C van Loon, B. Wall
Related Content
Claims (3)
In healthy young men, three days of immobilizing one leg causes a measurable reduction in quadriceps muscle size and a decrease in the rate of muscle protein synthesis compared to the unimmobilized leg, showing muscle loss occurs without changes in protein intake.
In healthy young men, consuming between 0.15 and 1.6 grams of protein per kilogram of body weight per day during three days of muscle immobilization does not change the rate of muscle mass loss or the suppression of myofibrillar protein synthesis.
Protein provides the amino acids that are used to build and repair muscle tissue.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.