How much protein people need
The official minimum for adults is 0.8 g per kg of body weight a day — enough to avoid a shortfall, not necessarily what works best. People who train for strength gain the most muscle up to about 1.6 g/kg a day, with some benefit up to about 2.2 g/kg.
When you eat less to lose fat, more protein — 1.6 to 2.2 g/kg — helps keep the muscle you have. After 65 the body uses protein less well, so expert groups advise at least 1.0 to 1.2 g/kg, more when you are ill or very active.
On GLP-1 medicines (semaglutide, tirzepatide)
These medicines make you eat much less, and part of the weight lost can be muscle. Doctors' groups suggest keeping protein up — often at least 1.2 g/kg of an adjusted weight — together with strength exercise. When appetite is small, put protein first on the plate. Your prescriber decides what is right for you.
Spread it over the day
Muscle responds best to 20–40 g of protein in a meal, so three or four protein-rich meals beat one big dinner. 30 g is roughly a palm-sized piece of chicken or fish, 250 g of Greek yoghurt or cottage cheese, four eggs, or a big bowl of lentils.
Over a BMI of 30, protein is counted on an adjusted weight rather than your full weight — otherwise the number comes out higher than the body can use.
Questions
- How much protein do I need to build muscle?
- About 1.6 g per kg of body weight a day gets most people most of the benefit; up to about 2.2 g/kg may help a little more. Training matters more than going higher.
- Is too much protein harmful?
- For healthy adults, intakes up to about 2 g/kg a day have not been shown to harm the kidneys. If you have kidney disease, ask your doctor before eating more protein.
- How much protein should I eat on Ozempic or Mounjaro?
- Often at least 1.2 g/kg of an adjusted body weight a day is suggested, with strength exercise, to help keep muscle while losing weight. Always follow what your prescriber says for you.
- Should I use my current weight or my goal weight?
- Your current weight, unless your BMI is over 30 — then an adjusted weight between your current and a healthy weight, which this calculator uses automatically.
Sources
- Morton RW 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. Br J Sports Med, 2018.
- Jäger R et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr, 2017.
- Bauer J et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc, 2013.
- Mechanick JI et al. Strategies for minimizing muscle loss during use of incretin-mimetic drugs for treatment of obesity. Obes Rev, 2025.