Effects of protein supplementation on muscle mass, muscle strength, and physical performance in older adults with physical inactivity: a systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 40200135 · doi:10.1186/s12877-025-05885-x
What was done
Systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the effects of protein supplementation on muscle mass, muscle strength, and physical performance in physically inactive older adults. Four databases (PubMed, EMBASE, Web of Science, and Cochrane Central Registry of Controlled Trials) were searched through January 31, 2025. Data from 6 RCTs (8 data groups) were synthesized using meta-analysis via RevMan 5.4 or narrative synthesis, stratified by three physical activity trajectories: sustained low physical activity (n = 1), transition to structured training from low physical activity (n = 4), and shift from moderate to low physical activity (n = 3).
What was found
Protein supplementation had no statistically significant effect on total lean body mass (p > 0.05). Secondary muscle mass parameters showed negligible intervention benefits, and outcomes for muscle strength and physical performance were heterogeneous. Specific effect sizes, confidence intervals, and total participant counts were not provided in the abstract.
Why it matters
Protein supplementation alone appears insufficient to improve lean body mass in physically inactive older adults, emphasizing the need for targeted physical activity alongside nutritional interventions.
Limits
Only 6 RCTs met inclusion criteria, with variable physical activity trajectories across small subgroups. Total sample size was not reported in the abstract, and functional performance outcomes were heterogeneous.
Cited by
- supports Studies demonstrate that increasing dietary protein intake without concurrent resistance training does not result in strength gains.