Protein supplementation and resistance training-induced strength gains in young adults: a meta-analysis
Chenkun Zhang; Yahai Wang; Wenying Huang
Frontiers in Nutrition · 2026
What the research tells us
Protein supplementation added a pooled 2.63 kg to bench-press gains (95% CI 0.77–4.49) and 7.40 kg to squat gains (2.15–12.66). Timing findings arose from comparisons across studies, not a randomized test of an optimal schedule.
Scope & interpretation
Heterogeneity was very high: I² 92.8% for bench press and 93.9% for squat. Baseline dietary intake was often not standardized or reported. Timing meta-regression was not conventionally significant (p=.073); shared controls and small subgroups limit precision. Authors’ GRADE labels do not remove these limitations or prove timing causality.
Study at a glance
- POPULATION & SAMPLE
- 23 randomized trials with 611 healthy adults younger than 45; most participants were men.
- EXPOSURE / INTERVENTION / SUBJECT
- Protein supplementation plus resistance training versus training alone or with placebo; timing, protein source and dose varied.
- OUTCOMES
- Changes in bench-press and squat strength; not a direct comparison of recovery speed or equal-total meal schedules.
- TIME FRAME
- Interventions 6–36 weeks; search through 1 April 2026; published 13 October 2026.
Cited on this site
Editorial & review record
Record for v1.0 · Updated
Editorial responsibility: TAP Editorial Team
Editorial note
Under the editorial responsibility of the TAP Editorial Team, this publication used AI assistance for content organization and editing.
Download detailed editorial record (JSON) ↓
How responsibilities and review are recorded ↗Scope of this reading note
PMC full text: eligibility, pooled and sensitivity results, meta-regression, GRADE discussion, limitations and declarations. No independent reanalysis of the underlying trials.
- Study funding
- Humanities and Social Sciences Foundation of Jiangxi Province’s universities, TY25202; Humanities and Social Sciences Research Project of Nanchang Normal College of Applied Technology, NYSRW2401.
- Competing interests
- Authors declared no commercial or financial relationships that could constitute a conflict.
Project support
Founded and supported by Resilio.
Read the editorial standards ↗