The Study
Pronounced energy restriction with elevated protein intake results in no change in proteolysis and reductions in skeletal muscle protein synthesis that are mitigated by resistance exercise
This study gave different diets and workouts to a small group of guys and measured how their muscles changed. It shows that what they ate and did seemed to affect their muscle building, but we can't say it will work the same for everyone else.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
When people eat much less food for 10 days, their muscles start to shrink — but this happens because their muscles stop making new protein, not because they break down more.
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 with more protein and lifting, muscles still lost some growth ability during severe dieting, meaning you can’t fully stop muscle loss just by eating more protein or working out.
- 2With low protein (1.2g/kg/d), muscle protein synthesis dropped 15–25%.
- 3With high protein (2.4g/kg/d) and lifting weights, it dropped only 10–20%.
- 4Muscle breakdown stayed the same no matter what.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The FASEB Journal
Year
2018
Authors
Amy J. Hector, C. McGlory, Felipe Damas, N. Mazara, S. Baker, Stuart M Phillips
Related Content
Claims (8)
When the body consumes significantly fewer calories than it expends, muscle protein synthesis decreases and muscle protein breakdown increases, resulting in reduced muscle growth.
In young, healthy men on a severe calorie-restricted diet for 10 days, consuming 2.4 grams of protein per kilogram of body weight per day reduces the loss of muscle protein synthesis compared to consuming 1.2 grams per kilogram per day, but does not stop it entirely.
In young, healthy men on a calorie-restricted diet for 10 days, consuming 2.4 grams of protein per kilogram of body weight per day reduces the loss of muscle protein synthesis compared to consuming 1.2 grams per kilogram per day, but does not stop it entirely.
When young, healthy men reduce their calorie intake by 40% for 10 days, muscle protein synthesis drops by 15-25% on a low protein diet of 1.2 grams per kilogram per day. This drop is smaller when protein intake is raised to 2.4 grams per kilogram per day and combined with resistance exercise.
In young, healthy men undergoing a 40% calorie reduction for 10 days, muscle breakdown does not change whether they consume 1.2 or 2.4 grams of protein per kilogram of body weight or whether they perform resistance exercise. The loss of muscle mass occurs because protein synthesis decreases, not because breakdown increases.
In young, healthy men on a reduced-calorie diet for 10 days, lifting weights with one leg increases muscle protein synthesis in that leg compared to the other leg, no matter how much protein they consume.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.