Protein is the nutrient with the strongest case for a fixed target. The right number depends on whether you're eating at maintenance, building, or in a deficit.
Building or maintaining muscle
A meta-analysis of 49 studies found that gains from resistance training levelled off around 1.6 g of protein per kg of body weight a day. The confidence interval stretched to about 2.2 g/kg, which makes a safe upper bound. A major position stand recommends 1.4 to 2.0 g/kg.
Cutting
When eating below maintenance, needs go up. For lean, trained people the recommendation is 2.3 to 3.1 g per kg of fat-free mass, higher for leaner people and bigger deficits. For body weight rather than fat-free mass, 1.8 to 2.7 g/kg is a common range for athletes in hypocaloric conditions.
Age
Older adults show anabolic resistance. They need about 0.4 g/kg per meal to maximise muscle protein synthesis, against about 0.25 g/kg for younger adults, and the benefit of extra protein declines with age.
Try it
Use our protein calculator to see a range for your weight.
References
- Morton RW et al. Br J Sports Med. 2018;52:376-384.
- Jager R et al. J Int Soc Sports Nutr. 2017;14:20.
- Helms ER, Aragon AA, Fitschen PJ. J Int Soc Sports Nutr. 2014;11:20.
- Phillips SM, Van Loon LJC. J Sports Sci. 2011;29(S1):S29-S38.
This is general information, not medical advice. See the health disclaimer.