The Study
Insulin does not stimulate muscle protein synthesis during increased plasma branched-chain amino acids alone but still decreases whole body proteolysis in humans
This study is like testing if adding sugar to your cereal makes your muscles grow bigger — and it found that even if you add sugar (insulin) and extra protein bits (BCAAs), your muscles don’t grow faster. But it only tested 14 healthy kids in a lab, so we can’t say it works the same for everyone.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Your muscles need more than just BCAA to grow—even if insulin is high. This study shows that lifting insulin and BCAA together doesn’t make muscles grow faster, but it does stop them from breaking down.
Where does this study sit?
Systematic Reviews & Meta-analyses
Max 100Randomized Trials
Max 90Cohort Studies
Max 72Case-Control
Max 58Cross-Sectional
Max 44Case Reports & Series
Max 30Expert Opinion
Max 533 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. Considered the gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—this means BCAA supplements alone won’t boost muscle growth, even with insulin spikes from carbs or supplements.
- 2Muscle growth rate stayed the same (0.04%→0.05%/h) with insulin + BCAA.
- 3Proteolysis dropped by 25–30% with insulin, no matter the BCAA level.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
American Journal of Physiology-Endocrinology and Metabolism
Year
2016
Authors
Sarah Everman, Christian Meyer, Lee Tran, Nyssa Hoffman, Chad C. Carroll, William L. Dedmon, Christos S. Katsanos
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.