How much protein do you need a day to build muscle

How much protein you need

The biggest answer to this question is the meta-analysis by Morton et al. (2018): 49 studies in which people lifted weights and ate different amounts of protein. The muscle gained from protein rose up to about 1.6 g per kg of bodyweight a day and then levelled off. The top of the confidence interval was around 2.2 g: if you want a safety margin, aim closer to that.

The International Society of Sports Nutrition position stand (ISSN, Jäger et al., 2017) gives a similar range for people who exercise — 1.4–2.0 g per kg a day. The numbers agree: for building muscle, 1.6 g is the working target and 2.2 g is the ceiling, above which you're paying for food, not growth.

Work it out for your weight

Multiply your bodyweight by 1.6 and by 2.2 — that's your daily range:

• 60 kg (132 lb) — 96–132 g.
• 70 kg (154 lb) — 112–154 g.
• 80 kg (176 lb) — 128–176 g.
• 90 kg (198 lb) — 144–198 g.
• 100 kg (220 lb) — 160–220 g.

If you carry a lot of extra fat, use the weight you're heading for, not your current one: fat doesn't need protein, and a number based on full bodyweight comes out too high. Quicker still — the protein calculator, which also splits the day into meals.

How to split it across meals

The daily total matters more than the schedule, but spreading protein evenly is convenient and works at least as well. The ISSN position stand recommends 20–40 g of protein per meal, every 3–4 hours. For an 80 kg lifter building muscle, that's four meals of 32–44 g or five of 26–35 g.

Before bed you can add a serving of slow protein — cottage cheese or casein: the ISSN names 30–40 g. It's not required, just a handy way to close the day's gap.

Two big meals instead of four isn't a disaster. Your muscle won't melt in one uneven week; what matters is that the daily total adds up day after day.

Where to get protein

Protein is ordinary food. Roughly this much per 100 g of food — the label has the exact figure:

• Chicken breast, turkey, beef, fish — about 20–25 g raw.
• Cottage cheese — about 11–12 g, Greek yogurt — about 10 g.
• An egg — about 6 g each.
• Canned tuna — about 23–25 g.
• Lentils, beans, chickpeas — about 7–9 g cooked; tofu — 8–15 g.

Plant protein counts too; you just need a little more of it, ideally from several sources. If food alone doesn't get you there, protein powder helps — more on that in the guide on whey protein.

When you need more

On a cut. When you eat fewer calories than you burn, your body is more willing to take energy from muscle too, and protein helps you hold on to it. Helms et al. (2014) recommend 2.3–3.1 g per kg of lean mass in a deficit — across total bodyweight, for a typical lifter, that's roughly 1.8–2.7 g per kg. The leaner you are and the deeper the deficit, the closer to the top end.

If you're coming back after a long break or started lifting after forty, extra protein won't hurt either: keep the day closer to 2 g per kg and don't skip meals. How a cut works as a whole is in the guide on cutting without losing muscle.

Do you need protein powder?

No. Protein powder is the same food, just in a tub: milk protein, dried and packed. Your muscles don't care whether 30 g of protein came from a shaker or a chicken breast.

In the Morton meta-analysis, supplemental protein helped people whose diet was short on it rather than acting as a growth trigger of its own. If you already reach 1.6 g per kg with food, the tub adds nothing. If you don't, a shake is the quickest way to close the gap.

Is a lot of protein safe?

In healthy people who exercise, these amounts haven't shown harm in research — that's the conclusion of the ISSN position stand. The "protein wrecks your kidneys" myth comes from advice for people whose kidneys are already sick.

Here's who should talk to a doctor first, not a calculator: kidney or liver disease, pregnancy and breastfeeding, a diet prescribed by a doctor. I'm a coach, not a doctor: these numbers are for healthy adults.

How to tell you're getting enough

Look at your log, not your plate. If the weights and reps on your lifts go up week to week and your bodyweight creeps up slowly on a bulk, you're eating enough. If your strength has been flat for a month while you sleep well and train regularly, check calories and protein first, then the program.

I log your workouts and bodyweight for you — there's a weight diary in the bot and in the app, and I work out your progress on every lift after each workout. How to build a program for size is in the guide on a muscle gain program.

Read next

• Protein per day
• Calories per day
• Whey protein: what it's for
• A workout program for muscle gain