Dose–response relationship between protein intake and muscle mass increase: a systematic review and meta-analysis of randomized controlled trials

Summary
Increasing protein intake may help yield greater muscle mass (1-3-3.5gm/kg). 
Even every 0.1 gram above 1.3 gm/kg matters.
Protein below 1.3gm/kg appears to have no muscle benefit.

Objective
The aim of this systematic review was to evaluate the dose–response relationship of the effects of protein intake on lean body mass.

Results

A total of 5402 study participants from 105 articles were included. In the multivariate spline model, the mean increase in lean body mass associated with an increase in protein intake of 0.1 g/kg of body weight per day was 0.39 kg (95%CI, 0.36–0.41) and 0.12 kg (95%CI, 0.11–0.14) below and above the total protein intake of 1.3 g/kg/d, respectively.

Conclusions
These findings suggest that slightly increasing current protein intake for several months by 0.1 g/kg/d in a dose-dependent manner over a range of doses from 0.5 to 3.5 g/kg/d may increase or maintain lean body mass.


Ryoichi Tagawa, Daiki Watanabe, Kyoko Ito, Keisuke Ueda, Kyosuke Nakayama, Chiaki Sanbongi, Motohiko Miyachi, Dose–response relationship between protein intake and muscle mass increase: a systematic review and meta-analysis of randomized controlled trials, Nutrition Reviews, Volume 79, Issue 1, January 2021, Pages 66–75, https://doi.org/10.1093/nutrit/nuaa104