How much protein do you need to build muscle?

The research gives a range, not one number. The two main sources agree on the shape of it:

• A 2018 meta-analysis of 49 trials (1,863 people) found that extra protein during weight training added a small amount of muscle and strength. The gains levelled off at about 1.6 g/kg/day. The 95% confidence interval ran from 1.0 to 2.2 g/kg.¹
• The International Society of Sports Nutrition says 1.4 to 2.0 g/kg/day is enough for most people who exercise to build or keep muscle.²

The meta-analysis authors point out that because the interval stretched up to 2.2, aiming for about 2.2 g/kg is a sensible way to be sure you are at the top of what helps.¹ So a working range is 1.6 to 2.2 g/kg. Use your body weight in kilograms, as it is today.

The effect is not large. Over a typical training block, extra protein added about 0.3 kg of lean mass on average. It matters more for people who already train than for people who just started, and a little less the older you are.¹

Multiply your body weight by the two ends of the range. For someone who weighs 80 kg:

Anywhere between 128 and 176 g is inside the range. Pick a number you can hit most days. Missing it by 10 g on a Tuesday changes nothing. What counts is what you eat on average over weeks.

A little. The usual advice is to split your protein over three to five meals instead of eating most of it at dinner. The position stand suggests about 0.25 g/kg per meal, or 20 to 40 g, roughly every 3 to 4 hours.² A 2018 review landed on 0.4 g/kg per meal over at least four meals.³ For 80 kg that is 20 to 32 g per meal.

Do not treat those numbers as a hard cap per meal. Older studies suggested that the body can only use 20 to 25 g at once. A 2023 lab study gave young men either 25 g or 100 g of protein after training. The 100 g dose led to a bigger and longer muscle-building response, still going after 12 hours.⁴ That was a small, controlled study, so it shows that a big meal is not wasted. It does not show that it is better.

In practice: if your daily total is right, spread it in a way that fits your day. Three or four meals with a decent portion of protein each is easy to keep up.

Animal foods such as meat, fish, eggs and dairy contain all the essential amino acids. So do soy foods such as tofu. Beans and lentils have less protein per portion, and you need more of them for the same amount. All foods with protein count towards your total. Here are some examples:

These are raw weights for meat, fish and tofu, so cooked portions weigh less and contain a bit more protein per 100 g. Packaging varies by brand, so check the label.⁵

A day that adds up to roughly the 80 kg example: 250 g Greek yoghurt (25 g), 150 g chicken breast (34 g), three eggs (19 g), 200 g salmon (41 g) and 150 g tofu (26 g) make 145 g. Bread, oats, rice and vegetables add more on top.

No. In the meta-analysis, intakes above about 1.6 g/kg/day gave no further gains in lean mass.¹ Going from 1.2 to 1.8 g/kg is worth the effort. Going from 2.2 to 3.0 mostly adds work: more chicken, more shakes and a bigger bill.

Protein also takes up room in your calorie budget. Each gram is 4 kcal, so every extra gram you eat leaves less room for carbohydrates and fat. Carbohydrates in particular fuel hard sessions. Set your protein, then fill the rest of your calories around it.

If you have a medical condition, or you are pregnant, ask a doctor or dietitian what is right for you before you change how much protein you eat.