The Claim

In resistance-trained young men, a daily protein intake of 1.8 g per kg body weight is sufficient to maximize muscle adaptations induced by resistance training, and the addition of 10 g/day of leucine provides no further benefit to these adaptations.

Source: Leucine Supplementation Has No Further Effect on Training-induced Muscle Adaptations

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
75score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

If you're a young man who lifts weights regularly, eating 1.8 grams of protein per kilogram of your body weight every day is enough to build as much muscle as you can from training—adding extra leucine powder won't help you get any bigger or stronger.

See the scientific wording

A daily protein intake of 1.8 g per kg body weight in resistance-trained young men is sufficient to maximize resistance training-induced muscle adaptations, as adding 10 g/day of leucine provides no further benefit.

What the research says

1 study
  1. Study: Leucine Supplementation Has No Further Effect on Training-induced Muscle Adaptations

    Scientists gave some guys extra leucine (a protein building block) while they lifted weights, but those who got the extra leucine didn’t get bigger or stronger than those who didn’t — meaning their normal protein intake was already enough.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.