How much protein do you need to eat to gain muscle?

Protein is every athlete and bodybuilders favorite macronutrient, and it’s pretty clear why: protein is the key nutrient for muscle growth and recovery. But how much protein do you need to eat to gain muscle?

A recent systematic review and meta-analysis published by the British Journal of Sports Medicine assessed the optimal protein intake for muscle gain in 49 studies. This is arguably the most reputable source of analysis, based on the eligibility criteria for each study needing to be a randomized controlled trial lasting for more than six weeks; the gold standard of research.

The researchers found that in every study protein intake positively correlated with muscle size and strength, but there was a cut off point. Researchers found that a low protein intake did stall muscle hypertrophy in some cases, as per the diagram below, but we’re talking 0.3 grams per pound.

The upper limit of the benefits of protein capped at 0.7 grams per pound of body weight. This led the researchers to conclude that 0.8 grams per pound - including a double 95 percent confidence level - was the maximum upper limit of protein requirements for healthy individuals. The confidence level added two standard deviations to ensure to be ‘safe’ that it’s the upper limit for everyone.

Figure 1 - Protein intake and fat free mass.

Based on this highly valid, reputable and rigorous testing of the optimal protein intake; it would be foolish to believe that consuming more than 0.8 grams of protein per pound of body weight would affect muscle growth. Even in the case of elite bodybuilders: a study published in 1992 tested the optimal protein intake in bodybuilders who trained for one and a half hours per day, six days per week and found that 0.75 grams per pound was still the upper limit.