How much protein do you need to build muscle?

If you lift weights and want more muscle, aim for about 1.6 g of protein per kg of body weight a day. That's about 0.7 g per pound. In the studies, extra protein stopped adding lean mass around there, on average.^[1] To cover your bases, go up to about 2.2 g per kg (1 g per pound).^[1]

For a 60 kg person, 1.6 g per kg works out to about 96 g a day. For an 85 kg person, it's about 136 g. When you eat it matters far less than how much you eat across the day.^[2]

Nobody knows the exact number for you. The 1.6 figure is an average with a wide range around it, so treat it as a starting point.

The last article covered how much to eat in total. This one covers the part of that total that lifting advice argues about most.

Why the number matters less than you'd think

Protein matters for muscle. But the fights about it are mostly about small differences.

Eat too little and you leave some muscle on the table. The RDA (recommended dietary allowance, the official daily amount for adults) is 0.8 g per kg. For people lifting to gain strength and muscle, that looks too low.^[1] Moderate evidence.

Eat far more than you need and you mostly spend money and effort. Shakes timed to the minute, chicken at every meal, worry about missing a post-workout "window". The studies below say the daily total does most of the work, and the extra effort buys little.

What the research says

A meta-analysis pools the results of many studies on the same question into one estimate. Two large ones on protein and lifting point the same way.

Extra protein helps, but only a little

A 2018 meta-analysis pooled 49 randomised controlled trials, or RCTs. (In an RCT, people are put into groups by chance, so the groups start out alike.) Together they included 1,863 healthy adults who lifted.^[1]

People who added protein gained about 0.3 kg more lean mass than people who didn't.^[1] Lean mass here means fat-free mass: everything in your body that isn't fat. Muscle is a big part of it, but so are water, organs and bone. The trials ran 6 to 52 weeks, and 13 weeks on average.^[1]

Strength moved a little too. Their one-rep max (the most weight you can lift for one rep) rose about 2.5 kg more.^[1]

A 2022 meta-analysis of 74 RCTs found the same thing: more protein gave a small extra gain in lean mass.^[3] Moderate evidence. Two meta-analyses agree, but the 2022 authors rated their own evidence as moderate. It's a small difference. You'd struggle to notice it in the mirror over a few months.

People who already lifted gained about 0.75 kg more lean mass from extra protein than people new to lifting.^[1] Limited evidence, from only 10 studies.

The lifting itself matters much more. The 2018 authors called training alone "the much more potent stimulus" for gaining muscle and strength.^[1] Moderate evidence. If your training isn't moving forward, fix progressive overload before you start weighing chicken.

Where the benefit levels off

The 2018 analysis also asked where extra protein stopped helping.

Two things stop this from being a hard rule. The range is wide. And the statistical test for that bend in the curve wasn't significant (p = 0.079), so chance can't be ruled out.^[1] Moderate evidence. Treat 1.6 as a good average, not a proven limit.

Because the range runs that high, the authors suggested about 2.2 g per kg for people who want the most from their training.^[1] Expert consensus. That's the authors' advice based on the range, not a tested finding.

The 2022 analysis lines up with this. In adults under 65, the extra benefit showed up at intakes of 1.6 g per kg a day or more.^[3]

A position stand is a group of experts summing up the research for a professional body. The International Society of Sports Nutrition (ISSN) says 1.4–2.0 g per kg a day is enough for most people who exercise.^[4] Expert consensus.

Put together: lifters do better above the RDA, and most land somewhere around 1.4 to 2.2 g per kg a day.^[1]^[3]^[4] Moderate evidence that more than the RDA helps. The exact top of the range is a best estimate.

Dieting may push the number up

A calorie is a unit of food energy. A calorie deficit means eating fewer calories than you burn, so you lose weight. A 2014 review of lean, trained lifters on a diet made the case for more protein than usual.^[5]

A 2025 analysis of 29 studies looked at lifters in a deficit. More protein went with less lean-mass loss, with no clear point where the benefit stopped.^[6] In their model, the trend line reached zero lean-mass loss at about 1.9 g per kg of body weight a day. Intakes above that, up to 3.2 g per kg, went with small gains.^[6] The link was stronger in men and in leaner people.^[6]

The authors called these results exploratory, because the studies differed a lot.^[6] Limited evidence. Participants averaged about 25 years old and had lifted for at least three months.^[6]

If you're lean and dieting, aim for around 2 g per kg or more: the top of the normal range or a bit above. That's our practical reading. Where losing muscle is a high risk and keeping it matters a lot to you, the authors' exploratory suggestion is 1.9–3.2 g per kg of body weight a day.^[6] Cut, bulk or recomp covers dieting in more depth.

Timing matters less than the daily total

A 2013 meta-analysis looked at eating protein right before or after training. Once the studies accounted for total daily protein, timing made no measurable difference to muscle or strength. For muscle growth, total daily protein was the strongest predictor.^[2] Moderate evidence. Most participants were young adults.^[2]

The ISSN adds that a workout's effect on muscle lasts at least 24 hours.^[4] Expert consensus. So there's no 30-minute "anabolic window" (a short spell after training when protein supposedly counts more) to race to.

Your body can use more than 20–30 g at a meal

You may have heard that your body can only use 20–30 g of protein at once. That isn't right. Some of a bigger serving gets burned for energy, but some goes to building tissue.^[7]

In one lab study, 36 young men were split into three groups after a workout: 25 g of protein, 100 g, or none. The 100 g group had a bigger response that lasted more than 12 hours.^[8] Limited evidence.

The study measured muscle protein synthesis (how fast the body builds new muscle protein) after one session. It didn't measure muscle growth over months. It explains why a big meal isn't wasted. It isn't advice to eat 100 g at once.

One review suggests about 0.4 g per kg per meal, over at least four meals.^[7] The ISSN suggests 20–40 g per serving, every 3–4 hours.^[4] Expert consensus. This is coaching practice, not a tested finding.

Higher protein and your kidneys

In trials of adults without kidney disease, kidney filtering (measured as GFR) changed about the same on higher-protein and normal-protein diets.^[9] That 2018 meta-analysis pooled 28 trials and 1,358 people. The high-protein groups ate about 1.8 g per kg a day on average.^[9]

Limited evidence. The authors rated the certainty of the evidence as low to very low. Most participants were middle-aged (49 on average) and carried extra weight (an average body mass index, or BMI, of 31), not young lifters. Some had type 2 diabetes or high blood pressure. People with kidney disease were left out.^[9]

You don't need protein powder

Whole food can cover your protein. Powder is a practical way to top up, not a requirement.^[4] Expert consensus. Protein powder gets its own section in supplements with evidence.

Check with a doctor or pharmacist before taking supplements, especially if you take medication or have a health condition. Supplements are less tightly regulated than medicines.

How to hit your protein target

Pick a number. Most people who lift: about 1.6 g per kg of body weight a day (0.7 g per pound). To cover your bases: up to 2.2 g per kg (1 g per pound). Lean and dieting: around 2 g per kg or more.
Do the sum. Multiply your body weight in kg by your number. Round it. Nobody needs the decimal.
Split it over your meals. Aim for about four meals, each with a decent serving.
Build each meal around a protein food. Meat, fish, eggs, Greek yoghurt, cottage cheese, tofu, beans or lentils. Grams vary a lot between foods, so read the label or look the food up.
Use powder only if it's easier. A shake is a convenience, like a sandwich you can drink.

Here's the sum for two people.

60 kg (about 132 lb).

At 1.6 g per kg: 60 × 1.6 = 96 g a day.
At 2.2 g per kg: 60 × 2.2 = 132 g a day.
At 0.4 g per kg per meal: 24 g per meal, four times a day, makes 96 g.

85 kg (about 187 lb).

At 1.6 g per kg: 85 × 1.6 = 136 g a day.
At 2.2 g per kg: 85 × 2.2 = 187 g a day. That's the "1 g per pound" people quote.
At 0.4 g per kg per meal: 34 g per meal, four times a day, makes 136 g.
Lean and dieting, at about 2 g per kg: 170 g a day or more.

What's practical can differ from the top of the range. If 2.2 g per kg means forcing food down, stay near 1.6. That's where the average benefit levelled off.

If counting food makes you anxious, or you have a history of an eating disorder, skip the numbers and speak to a doctor or a registered dietitian.

Otherwise, track your protein for a week. A week is enough to see whether you're near your number or nowhere close. After that you'll know which meals do the work, and you can track less.

Common mistakes

Treating 1 g per pound as the minimum. It's a round number, so it spreads. If you're not dieting, it's the top of the research range, not the floor. Start at about 1.6 g per kg and go up if you like.
Racing to drink a shake after training. The "window" story is old and sticky. Hit your daily total. Eat when it suits your day.
Cutting meals into tiny servings. People do this because they heard the body can't use more than 20–30 g at once. Eat normal meals with a decent serving of protein each.
Fixing protein while training stalls. Protein is easier to buy than effort. If the weights on the bar aren't going up, look at your training first.
Copying advice that wasn't written for you. Most protein studies used healthy adults, mostly men. If you have kidney disease, are under 18 or are pregnant, talk to your doctor (or midwife) first.

How Gymbers fits

A protein number only helps if you know where you stand against it. The Gymbers app logs protein, calories, carbs and fat against your daily targets. Find a food by searching the food database or scanning a barcode. Add your own foods too, like the shake or the stew you make every week.