Dose-response relationship between protein intake and muscle mass increase: a systematic review and meta-analysis of randomized controlled trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 33300582 · doi:10.1093/nutrit/nuaa104
What was done
Authors conducted a systematic review and dose-response meta-analysis of randomized controlled trials evaluating the effects of protein intake on lean body mass. PubMed and Ichushi-Web were searched electronically along with manual reference list searches. Data spanning doses from 0.5 to 3.5 g/kg/day were analyzed using a multivariate spline model.
What was found
Across 105 articles comprising 5,402 participants, each 0.1 g/kg/day increase in protein intake was associated with a mean lean body mass increase of 0.39 kg (95% CI, 0.36 to 0.41) when baseline intake was below 1.3 g/kg/day, and 0.12 kg (95% CI, 0.11 to 0.14) when intake was above 1.3 g/kg/day.
Why it matters
This review provides quantitative dose-response evidence that increasing protein intake supports lean mass gains up to 3.5 g/kg/day, though the efficiency of additional protein drops noticeably beyond 1.3 g/kg/day.
Limits
The abstract does not report details on participant demographics (age, sex, training status), concurrent exercise interventions such as resistance training, trial durations, or protein source and quality.
Cited by
- supports During resistance training, the majority of strength and muscle-building benefits from protein are achieved at 1.2 g/kg, with minimal additional benefits gained between 1.2 and 1.6 g/kg.