Research
Hormonal
Whey protein supplementation combined with resistance training significantly improves body composition (lean mass gain and fat mass loss) and muscular strength specifically in individuals under 40 years of age, but not in older individuals.
If you are under 40, whey protein after resistance training is a proven strategy to build muscle and lose fat. If you are over 40, this specific combination may not yield the same results, and you should consider discussing multi-nutrient options (like vitamin D and leucine-enriched whey) with a professional.
GoodQualifiesHIGH confidence
WP-RT improved lean mass (MD 0.46 kg [−0.02, 0.94]; p=0.06) but not in older individuals (−0.19 kg [−0.53, 0.14]; p=0.26)... WP-RT significantly decreased fat mass only in individuals aged less than 40 years (MD −0.62 kg [−1.05, −0.19]; p=0.004) but not in older individuals (0.62 kg [−0.08, 1.33]; p=0.08).
Why this rating
Based on subgroup analysis of 21 RCTs.
Source
Effect of whey protein supplementation during resistance training sessions on body mass and muscular strength: a meta-analysis
Meng Li et al. · Food & Function · 2019
DOI 10.1039/c9fo00182d
Meta-analysis · 21 studiesCited 24×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Whey protein supplementation combined with resistance training significantly improves lean mass, fat mass, and muscular strength in healthy individuals, but fails to produce these benefits in individuals with pathological conditions.Good
- Whey protein supplementation combined with resistance training is less effective in individuals with pathological conditions compared to healthy individuals, showing no significant improvement in lean mass, fat mass, or muscular strength.Moderate
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