How Much Protein Do You Need to Build Muscle?
What a meta-analysis of protein supplementation and resistance training shows, where extra protein stops helping, and how to hit your target.
The short answer
Around 1.6 g of protein per kg of body weight per day is a well-supported target for lifters; in a large meta-analysis, intakes above about 1.6 g/kg/day added no further gains in lean mass.
What the evidence says
A systematic review, meta-analysis and meta-regression in the British Journal of Sports Medicine found that protein supplementation increased gains in muscle strength and size during prolonged resistance training. The effect was smaller with increasing age and larger in trained people, and gains plateaued at a total intake of about 1.6 g/kg/day.
Evidence: [1]
What to do
Higher intakes are generally fine for healthy people but unlikely to add more muscle. People with kidney disease or other medical conditions should follow their doctor’s advice.
- Multiply body weight in kg by about 1.6 — for 80 kg, around 130 g per day.
- Spread it over 3–5 meals with a solid protein source in each.
- Protein powder is a convenience, not a requirement.
Common mistakes
- Very high protein with too few total calories to support training.
- Relying on one huge protein meal a day.
Bottom line
About 1.6 g/kg/day covers what most lifters need; consistency matters more than timing tricks.
References
- [1] Morton RW, Murphy KT, McKellar SR, et al. 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. 2018;52(6):376–384. Systematic review, meta-analysis and meta-regression doi.org/10.1136/bjsports-2017-097608
This guide summarises published research for healthy adults. It is general information, not medical advice — if you have a health condition, injury or take medication, talk to a qualified professional before changing your training or supplements.