How much protein per day to build muscle? What science says

The key number: 1.6 g per kilogram

In 2018, a research team led by Morton and Schoenfeld published the largest meta-analysis on this topic in the British Journal of Sports Medicine: 49 controlled studies, 1,863 participants. Their conclusion is clear: muscle mass gains increase with protein intake but plateau around 1.6 g per kilogram of body weight per day.

Beyond this threshold, eating more protein does not produce additional measurable muscle gains. This is a robust result, obtained by aggregating data from varied populations (young, older, male, female, beginners, trained individuals).

For a 75 kg person, that means roughly 120 g of protein per day — the equivalent of two portions of chicken (200 g each) and a Greek yogurt, or a distribution across 4 meals at approximately 30 g each.

The official range: 1.4 to 2.0 g/kg

The official position of the International Society of Sports Nutrition (ISSN), published in 2017 by Jäger and colleagues, recommends an intake of 1.4 to 2.0 g of protein per kg of body weight per day for most individuals practicing resistance training.

This range is deliberately broad: it accounts for individual differences (training level, muscle mass, age, goals). A beginner can progress perfectly well with 1.4 g/kg, while an experienced athlete in an intensive growth phase may aim for the upper end.

The key point: there is no need to systematically aim for the maximum. Staying between 1.4 and 1.8 g/kg is sufficient for the vast majority of athletes, and Morton's meta-analysis confirms that the marginal benefit beyond 1.6 g/kg is virtually zero.

During a cut: increase protein

When in a caloric deficit — eating less than you burn to lose fat — the body tends to draw from its reserves, including muscle. To minimize lean mass loss, the ISSN recommends increasing protein intake to 2.3 to 3.1 g/kg of lean body mass per day.

This is significantly higher than for muscle building, and it makes sense: protein plays a protective role when the body is in restriction. It fuels muscle protein synthesis and increases satiety, helping maintain the deficit without excessive hunger.

For our 75 kg person during a cut, that rises to roughly 170 to 230 g of protein per day. An intake that requires serious nutritional planning — exactly the kind of calculation MoovX automates for you.

How to distribute throughout the day

Total daily protein intake is the most important factor, but distribution also plays a role. Research shows that muscle protein synthesis is optimized when protein is spread evenly across the day rather than concentrated in one or two large meals.

The practical recommendation: aim for about 0.25 g/kg of body weight per serving (or 20 to 40 g depending on your build), spread across 3 to 5 meals spaced 3 to 4 hours apart. For our 75 kg person, that means approximately 20 g of protein 4 to 6 times per day.

Scientific references

1. Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, et al. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine. Lien
2. Jäger R, Kerksick CM, Campbell BI, et al. (2017). International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition. Lien