The Study
Effects of high versus standard essential amino acid intakes on whole-body protein turnover and mixed muscle protein synthesis during energy deficit: A randomized, crossover study.
This study gave two different amounts of amino acid drinks to 19 young men after they ate less food than usual, then measured how their bodies used protein. It shows that the bigger dose made their whole body use protein better, but didn’t make their muscles grow more. It’s like testing two types of fertilizer on the same plants — we know which one helped the plant overall, but not which helped the leaves more.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
When people eat less food and exercise, giving them more amino acids helps their whole body make protein and stop breaking it down—but doesn’t make their muscles grow faster.
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 572 / 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—this means more amino acids help your body stay in repair mode during dieting, even if your muscles don’t grow faster from the extra dose.
- 2With 23.5g EAA: protein synthesis went up by 3.4g/180min, breakdown went down by 15.6g/180min, net balance improved by 19.0g/180min.
- 3Muscle protein synthesis rates were the same with 7.87g or 23.5g EAA.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Clinical nutrition
Year
2020
Authors
Jess A Gwin, D. Church, Adrienne Hatch-McChesney, Emily E. Howard, C. Carrigan, Nancy E. Murphy, Marques A. Wilson, Lee M. Margolis, J. Carbone, R. Wolfe, A. Ferrando, S. Pasiakos
Related Content
Claims (7)
In young men who are in a calorie deficit, taking a higher dose of essential amino acids after weight training does not lead to a higher rate of muscle protein synthesis compared to a lower dose.
When young adult men are in a calorie-deficient state, consuming 23.5 grams of essential amino acids leads to higher levels of these amino acids in the blood than consuming 7.87 grams.
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 adult males with a 30% energy deficit over five days, consuming 23.5 grams of essential amino acids after resistance exercise increases whole-body protein synthesis by 3.4 grams per 180 minutes and decreases protein breakdown by 15.6 grams per 180 minutes compared to 7.87 grams, leading to a more positive net protein balance, with no change in muscle protein synthesis rates.
In young men on a 5-day low-calorie diet, taking a higher dose of essential amino acids (23.5 grams) compared to a lower dose (7.87 grams) increases overall protein synthesis and decreases protein breakdown, leading to a better net protein balance, but does not increase muscle protein synthesis during rest or after weight training.
In young men eating fewer calories than they burn, taking either a low or high dose of essential amino acids results in the same rate of muscle protein synthesis during rest and after weight training.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.