The recommended amount of protein for adults is 0.8 grams per kilogram of body weight a day, about 0.36 grams per pound. It's set high enough to cover almost everyone, and anywhere from 10% to 35% of your calories is a healthy range. Expert groups on aging suggest more after 65, at least 1.0 to 1.2 grams per kilogram.
Key takeaways
The recommended amount for healthy adults of every age is 0.8 grams per kilogram a day (Deutz et al., 2014), set to cover nearly everyone (Rand et al., 2003).
Expert groups suggest at least 1.0 to 1.2 grams per kilogram for healthy people over 65 (Bauer et al., 2013).
In some studies, the total amount mattered more than the timing (Kim et al., 2015).
Plants can supply all the protein you need, from a variety of foods over the day (Mariotti and Gardner, 2019).
What's the recommended amount of protein?
The recommended amount for healthy adults is 0.8 grams of protein per kilogram of body weight a day, the same at every age (Deutz et al., 2014). The National Academies base protein needs on studies that measure how much protein the body keeps and loses, and they set a healthy range of 10% to 35% of calories (NASEM, 2024).
The research behind the number found adults need about 0.65 grams per kilogram on average. The 0.8 figure is set higher to cover nearly everyone (Rand et al., 2003). So most people need less than 0.8, which is how it covers almost everyone.
How do you work out your number?
Multiply your weight in kilograms by 0.8, or by 1.0 to 1.2 if you're over 65. To get kilograms, divide your weight in pounds by 2.2.
Body weight | At 0.8 grams per kg | At 1.0 to 1.2 grams per kg (over 65) |
|---|---|---|
50 kg (110 lb) | 40 g | 50 to 60 g |
60 kg (132 lb) | 48 g | 60 to 72 g |
70 kg (154 lb) | 56 g | 70 to 84 g |
80 kg (176 lb) | 64 g | 80 to 96 g |
90 kg (198 lb) | 72 g | 90 to 108 g |
100 kg (220 lb) | 80 g | 100 to 120 g |
If you have kidney disease, ask your doctor or a dietitian for your number instead (NIDDK).
Do older adults need more protein?
Expert groups on aging recommend it. They suggest at least 1.0 to 1.2 grams per kilogram a day for healthy people over 65, and 1.2 to 1.5 during an illness (Bauer et al., 2013; Deutz et al., 2014). The studies behind the 0.8 figure didn't find a difference by age (Rand et al., 2003), so this is a recommendation from groups who focus on aging, aimed at keeping muscle.
Muscle is the reason. As you age, you can slowly lose muscle and strength, which doctors call sarcopenia. It makes falls, fractures and disability more likely, and it can begin earlier than old age (Cruz-Jentoft et al., 2019). More on what the scale can and can't tell you about muscle is in muscle, water, fat.
Protein works best alongside exercise. In a review of 74 trials, mostly in adults under 65, extra protein brought small gains in lean mass, mostly when paired with strength training (Nunes et al., 2022). For why you want both kinds of exercise, see cardio vs. strength.
Does it matter when you eat protein?
The evidence is mixed. In a small study of eight adults, spreading protein evenly across three meals raised the rate of muscle protein building by about 25% over a day, compared with eating most of it at dinner (Mamerow et al., 2014). That study was partly funded by a beef industry group. A review found an even spread linked to more muscle mass in three of seven studies, though not to more strength (Jespersen and Agergaard, 2021).
Other studies point to the total. In one, the amount mattered and the pattern didn't (Kim et al., 2015). In an 8-week trial with 14 older adults, even and uneven patterns showed no measurable difference in muscle or strength (Kim et al., 2018). Even the idea that the body can use only about 20 to 25 grams at once is in doubt. In young men after exercise, 100 grams at once gave a bigger, longer response than 25 grams (Trommelen et al., 2023).
So aim for your daily total first. Spreading protein out is a fine way to get there.
Is plant protein as good as animal protein?
You can meet your needs either way. You don't need animal products to get enough protein (MedlinePlus). Typical vegetarian diets supply more than enough protein for adults, though needs in older age are less clear (Mariotti and Gardner, 2019).
Plant proteins differ a little. Grains run low in lysine, one of protein's building blocks, and beans, lentils and peas make up for it. A variety over the day is enough; there's no need to combine them at each meal (Mariotti and Gardner, 2019). The American Heart Association suggests choosing protein mostly from plants, with regular fish and seafood and low-fat or fat-free dairy (Lichtenstein et al., 2021).
Is a lot of protein bad for your kidneys?
Short trials haven't shown harm in people with healthy kidneys. A review of 28 trials in adults without kidney disease found higher protein didn't affect how well the kidneys filter blood (Devries et al., 2018). Most of those trials lasted 12 weeks or less, and kidney experts say to take care if you're at high risk of kidney disease (Ko et al., 2020).
If you already have kidney disease, the advice is different. Some people with severe kidney disease need less protein, not more (Bauer et al., 2013). Talk with your doctor or a dietitian about the right amount for you (NIDDK).
Frequently asked questions
Do men and women need different amounts? Not per kilogram. The research behind the recommendation found no significant difference in protein needs by sex or age group (Rand et al., 2003). Someone who weighs more needs more in total.
Can a food log tell me how much protein I eat? It's a reasonable guide. In one study, food records got the share of calories from protein about right, even when total calories ran low (Park et al., 2018). See how accurate the calories you log are.
Does soy lower cholesterol? Slightly. When people ate about 50 grams of soy protein a day, their LDL cholesterol fell by about 3% on average (Sacks et al., 2006).
How Knit shows your protein
When you log food in an app connected to Apple Health, Knit shows your daily protein in the Record tab, under Nutrition. You can compare a typical day with the amount you're aiming for.
