How much protein per day
according to the studies

Your amount, at a glance

Our calorie and macro calculator starts at 1.8 g/kg, within what the studies see for people who train, and you can change it to fit your case.

Where 0.8 comes from and why it is a minimum

• Strong evidence · meta-analyses It is what prevents losing protein from the body. It comes from nitrogen balance studies: 19 studies with 235 people put the average requirement at 0.65 g/kg, and 0.83 g/kg covers 97.5% of people (Rand 2003). It is the figure of the European Food Safety Authority (EFSA 2012); in the United States, 0.8 g/kg (National Academies).
• Strong evidence · meta-analyses If you don’t train or diet, it is enough. Above 0.8 g/kg muscle mass did not change in those people; it did help people who do strength training or are in a deficit (Hudson 2020, 18 studies).

To build muscle

• Strong evidence · meta-analyses Around 1.6 g/kg, with a margin. In 49 trials with 1,863 people who did strength training, raising protein added 0.30 kg of lean mass and 2.5 kg of maximal strength. The gain leveled off at about 1.62 g/kg a day, but with a margin of 1.03 to 2.20, and the authors suggest up to about 2.2 g/kg for people who want to get the most out of it. The effect was larger in people already trained and smaller with age (Morton 2018).
• Strong evidence · meta-analyses The effect is real but small, and it was seen with 1.6 g/kg or more in people under 65 and with 1.2–1.59 in older adults (Nunes 2022, 74 trials).
• Strong evidence · meta-analyses What counts most is getting out of the low range: each extra 0.1 g/kg added, on average, 0.39 kg of lean mass below 1.3 g/kg and 0.12 kg above it, especially in people who did not train; with strength training the effect was smaller and without that drop (Tagawa 2021). And extra protein only added strength if people also trained (Tagawa 2022).
• Weak evidence · experts or few studies The International Society of Sports Nutrition recommends 1.4–2.0 g/kg for people who train (ISSN 2017).

To lose fat without losing muscle

• Strong evidence · meta-analyses In a deficit, eating more than 0.8 g/kg protects muscle: 0.36 kg more lean mass was preserved (Hudson 2020).
• Moderate evidence · trials With a large deficit and hard training, 40 young men for 4 weeks: with 2.4 g/kg they gained 1.2 kg of muscle and lost 4.8 kg of fat; with 1.2 g/kg, 0.1 kg of muscle and 3.5 kg of fat (Longland 2016).
• Weak evidence · experts or few studies For lean athletes on a diet 2.3–3.1 g per kilo of lean mass is suggested (Helms 2014, only 6 studies; ISSN 2017).

Per kilo of what: body weight or lean mass

Almost all the figures on this page are per kilo of body weight. But the one for losing fat is not: Helms wrote it per kilo of lean mass, which is the kilos that are not fat. And the difference is not a detail. With 20% body fat both ways are similar; with 45%, the same rule asks for almost twice what is needed. Protein is used by muscle, and fat does not ask for it.

• Strong evidence · meta-analyses Calculating it on body weight fails precisely in the people who weigh the most. If someone is above or below their weight, their body has proportionally less or more protein per kilo, so calculating it on actual weight overshoots or falls short (Weijs and Wolfe 2016).
• Moderate evidence · trials With obesity, while losing weight, the cut-off is 1.2 g per kilo of body weight or 1.9 g per kilo of lean mass (Weijs and Wolfe 2016). They are two sides of the same recommendation.
• Weak evidence · experts or few studies For building muscle there is no figure per kilo of lean mass. We looked for it: neither the meta-analysis by Morton 2018 nor the position stand of the ISSN 2017 give any recommendation per kilo of lean mass — they are all per kilo of body weight. So for building we stay with 1.6 g/kg of body weight.

How to know your lean mass without a bioimpedance scale

• Moderate evidence · trials With neck, waist and height. The US Navy formula (Hodgdon and Beckett, 1984) estimates body fat with a tape measure, with about 3–4 points of error compared with densitometry. Women also need the hip measurement.
• Moderate evidence · trials Without measuring anything, with sex, age, height and weight: the CUN-BAE, from the Clínica Universidad de Navarra in Spain, built with 6,510 people and checked against plethysmography (Gómez-Ambrosi 2012). About 4–5 points of error, a little worse than the previous one because it infers fat from weight instead of measuring where it is.
• Weak evidence · experts or few studies The days you train are not part of either, and it is the question we are asked most. At the same weight, height and age, someone who does strength training has more muscle than someone who doesn’t — but there is no published, validated equation that captures that, so nobody can really calculate it. What does pick it up, indirectly, is the tape-measure formula: a trained body has a smaller waist for the same weight.

These are estimates, not a measurement. Neither of them weighs you on the inside. But being four points of body fat off moves protein by a few grams, while confusing body weight with lean mass can double it.

As you get older

• Weak evidence · experts or few studies At least 1.0–1.2 g/kg, 1.2 or more if you exercise and 1.2–1.5 with illness; with advanced kidney failure not on dialysis, limit it (PROT-AGE 2013; ESPEN 2014). These are expert consensus statements.
• Strong evidence · meta-analyses Protein plus exercise, better than exercise alone against age-related muscle loss, although with very low certainty (Yoshimura 2025, 13 trials).

How much at each meal, and when?

• What is clear is the daily total. How you split it and the timing are details with little evidence.
• Moderate evidence · trials «More than 30 g per meal is wasted» is a myth. After training, 40 g stimulated more than 20 g (Macnaughton 2016), and 100 g extended the response for more than 12 hours compared with 25 g (Trommelen 2023, 36 men; it measures the response to one session, not the muscle gained).
• Weak evidence · experts or few studies Splitting it over 3–4 meals (about 0.3–0.4 g/kg at each) is a reasonable recommendation (Schoenfeld and Aragon 2018), but that it gives more muscle has not been shown (Jespersen 2021).
• Strong evidence · meta-analyses Before or after training makes no difference for muscle mass (Casuso 2025).
• Weak evidence · experts or few studies Protein before bed: one trial saw more strength and muscle (Snijders 2015), but that group ate more protein in total, so it is not known whether it was the timing (Reis 2021).

How much is too much?

• Weak evidence · experts or few studies Up to twice the recommendation (about 1.7 g/kg) is considered safe; there is no official maximum (EFSA 2012).
• Weak evidence · experts or few studies Healthy kidneys: in 28 trials with 1,358 people and high-protein diets (1.5 g/kg or more, at least 20% of calories or 100 g a day or more), kidney function changed the same as with less protein. They were short trials and the quality of the evidence is low (Devries 2018).
• With chronic kidney disease, it does need to be limited: the international guideline suggests 0.8 g/kg in advanced stages and avoiding more than 1.3 g/kg if there is a risk of it getting worse (KDIGO 2024). With your doctor.
• Strong evidence · meta-analyses «Protein leaches calcium from your bones» does not hold up: no harm was seen, and perhaps a small benefit in the spine (Shams-White 2017; Darling 2019).

Animal or plant?

• Moderate evidence · trials With the same total amount, the same muscle: vegans and omnivores at 1.6 g/kg gained the same (Hevia-Larraín 2021), and also at about 2 g/kg (Monteyne 2023).
• Strong evidence · meta-analyses Soy performs like milk (Messina 2018; Reid-McCann 2025). Other plant proteins gave a little less muscle in the meta-analyses (Reid-McCann 2025); combining them and reaching the total helps. «Higher-quality» protein gave a bit more strength, but not more muscle (Morgan 2021).

Do you need shakes?

No, if you get there with food. The benefit in the studies is in raising the daily total (Morton 2018); a shake is just a convenient way to get there (ISSN 2017).

How much protein everyday foods have

• One egg (about 60 g): about 6–7 g (BEDCA, the Spanish food composition database).
• 100 g of cooked chicken breast: 22–31 g, depending on how it is cooked (BEDCA; USDA).
• 100 g of cooked lentils: about 9 g (USDA). Dry they have about 24 g, but cooking triples their weight.
• 100 g of drained canned tuna: about 23–29 g (BEDCA; USDA).
• Greek yogurt: it depends a lot on the brand, from about 4 to 10 g per 100 g. Check the label.

Frequently asked questions