Research
Hormonal
Supplementing meals with 3-4 grams of leucine can improve or normalize muscle protein synthesis in aging muscle, acting as a trigger for the mTOR pathway.
If you are older, adding 3-4 grams of leucine to your meals (or eating leucine-rich foods like beef or whey) can help trigger muscle growth. However, if you already eat enough protein, you might not need extra leucine supplements.
ModerateQualifiesMEDIUM confidence
Several acute human studies suggest that supplementing meals with a relatively small amount of leucine (approx. 3–4 g/meal) may act as a “trigger” and improve or normalize muscle protein synthesis in aging muscle.
Why this rating
Supported by acute human studies, but long-term clinical data in sick populations is lacking.
Source
Variation in Protein Origin and Utilization: Research and Clinical Application
Douglas Paddon‐Jones et al. · Nutrition in Clinical Practice · 2017
DOI 10.1177/0884533617691244
narrative_reviewCited 14×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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