Research

Hormonal

The efficacy of protein supplementation on fat-free mass gains is moderated by age and training status: it is more effective in resistance-trained individuals and less effective in older adults (>45 years).

If you are experienced in resistance training or are over 45, protein supplementation is particularly important for maximizing muscle gains. Novices and younger individuals may see smaller relative benefits from supplementation if their baseline intake is already adequate.

WeakQualifiesHIGH confidence
The impact of protein supplementation on gains in FFM was reduced with increasing age... and was more effective in resistance-trained individuals
Robert W. Morton et al. · British Journal of Sports Medicine · 2017

Why this rating

Based on meta-regression of the same high-quality dataset.

Source

A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults

Robert W. Morton et al. · British Journal of Sports Medicine · 2017

DOI 10.1136/bjsports-2017-097608

Meta-analysis · 49 studiesCited 1,050×
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DOI resolved against Crossref · corpus check 2026-06-10

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