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Key takeaways
- Minimum: 0.8 g per kg of body weight a day in the US (0.83 g/kg in Europe). That is the amount to avoid deficiency, not the amount that is optimal for everyone.1, 2
- Training or losing weight: 1.4 to 2.0 g/kg. Gains in muscle from extra protein level off at about 1.6 g/kg a day in the largest meta-analysis to date.3, 4
- Over 65: 1.0 to 1.2 g/kg to slow age-related muscle loss.5
- Per meal: about 0.4 g/kg, three to four times a day, works better than one huge serving.6
- Kidneys: higher protein does not harm kidney function in healthy adults. People with diagnosed kidney disease are the exception and need a lower, supervised target.8, 9
The official minimum
The Recommended Dietary Allowance for protein in the United States is 0.8 grams per kilogram of body weight per day for adults. It is set to meet the needs of nearly all healthy people, and the same report allows protein to make up anywhere from 10 to 35 percent of your calories.1 The European Food Safety Authority lands in the same place with a population reference intake of 0.83 g/kg.2
For a 70 kg (154 lb) adult that is 56 to 58 g a day. For a 90 kg adult it is about 72 g. The important point is what the number means: it is the floor that prevents deficiency in a sedentary adult who is not trying to change their body. It is not the level that maximizes muscle, satiety or recovery.
When more helps
The International Society of Sports Nutrition's position stand puts the range for building or keeping muscle in people who exercise at 1.4 to 2.0 g/kg a day.3 A 2018 meta-analysis of 49 trials with 1,863 participants tested how much extra protein actually adds to resistance training. Gains in lean mass rose with intake and then flattened at about 1.62 g/kg a day; the confidence interval ran up to 2.2 g/kg, which is why many coaches round the target up for safety.4
During a calorie deficit the case for the upper end gets stronger. Protein protects muscle while fat is lost, has the highest thermic effect of the three macronutrients (digesting it costs roughly 20 to 30 percent of its calories, against 5 to 10 percent for carbohydrate and 0 to 3 percent for fat), and is the most filling per calorie.7 For lean, resistance-trained people cutting weight, the ISSN cites intakes of 2.3 to 3.1 g per kg of fat-free mass to hold on to muscle.3 For most people on a moderate deficit, 1.6 to 2.0 g/kg of body weight is a practical ceiling.
After about 65, the body becomes less responsive to protein and muscle is lost faster. The PROT-AGE expert group recommends 1.0 to 1.2 g/kg a day for healthy older adults, and more during illness or with regular exercise.5
Targets by goal
| Situation | Grams per kg of body weight | For a 70 kg adult | Source |
|---|---|---|---|
| Sedentary, maintaining weight | 0.8 | 56 g | US RDA1 |
| Healthy adult over 65 | 1.0 to 1.2 | 70 to 84 g | PROT-AGE5 |
| Exercising regularly, building or keeping muscle | 1.4 to 2.0 | 98 to 140 g | ISSN3 |
| Point where extra protein stops adding muscle | about 1.6 | 112 g | Morton et al.4 |
| Losing fat while training | 1.6 to 2.0 (higher per kg of lean mass if very lean) | 112 to 140 g | ISSN3 |
If you carry a lot of body fat, scale the target to your goal weight or lean mass rather than your current weight, otherwise the number becomes unrealistic. A 120 kg person aiming for 90 kg can use 90 kg in the calculation.
Spreading it across the day
The old claim that the body can only use 20 or 30 g of protein per meal does not hold up. A 2018 review of the evidence concluded that muscle building is best served by about 0.4 g/kg per meal spread across at least four meals, which adds up to the 1.6 g/kg daily target, with 0.55 g/kg per meal as a reasonable upper figure.6 For a 70 kg person that is 28 to 38 g per meal.
In practice, the easiest fix for most people is breakfast. A typical pastry-and-coffee morning has 5 to 10 g of protein; eggs, Greek yogurt, cottage cheese or leftover dinner get it to 25 to 30 g without changing anything else.
Where to get it
Approximate values from the USDA FoodData Central database, per 100 g unless stated.10
| Food | Protein | Worth knowing |
|---|---|---|
| Chicken breast, cooked, skinless | 31 g | Lean; the benchmark most other foods are compared to |
| Salmon, cooked | 25 g | Brings omega-3 fats with it |
| Lean beef, cooked | 26 g | Also iron and zinc |
| Eggs | 13 g (about 6 g per large egg) | Complete protein, inexpensive |
| Greek yogurt, plain, nonfat | 10 g | Twice the protein of regular yogurt |
| Cottage cheese | 11 g | Check sodium if you watch it |
| Tempeh | 20 g | Fermented soy; firm and filling |
| Tofu, firm | 15 to 17 g | Varies by brand and firmness |
| Lentils, cooked | 9 g | Plus about 8 g of fiber |
| Chickpeas, cooked | 9 g | Same fiber bonus |
| Edamame, cooked | 11 g | A rare complete plant protein |
| Milk | 3.4 g (about 8 g per 250 ml glass) | Counts toward the total |
Plant proteins work fine; they tend to be lower in one or two amino acids each, which mixing sources across the day solves. Legumes and grains together, soy, and dairy if you eat it, cover the gaps.
Protein and your kidneys
The worry that high-protein diets damage healthy kidneys is not supported by the evidence. A 2018 systematic review and meta-analysis of 28 trials found no difference in kidney function between adults eating higher protein diets and those eating lower or normal amounts.8
Diagnosed chronic kidney disease is a different situation. The KDOQI clinical practice guideline recommends that metabolically stable adults with stage 3 to 5 kidney disease who are not on dialysis restrict protein to 0.55 to 0.60 g/kg a day under close clinical supervision.9 If you have kidney disease, your nephrologist's number overrides everything in this article.
Questions people ask
How much protein do I need to build muscle?
About 1.6 g per kg of body weight a day is where extra protein stops adding lean mass in the largest meta-analysis, with the ISSN range running 1.4 to 2.0 g/kg.3, 4 For a 70 kg person that is roughly 110 to 140 g a day, spread over three or four meals, alongside resistance training.
Is too much protein bad for your kidneys?
Not in healthy adults. A meta-analysis of 28 trials found no change in kidney function on higher-protein diets.8 People with chronic kidney disease are the exception: guidelines recommend a supervised low-protein diet of 0.55 to 0.60 g/kg for stages 3 to 5.9
Can the body only absorb 30 g of protein per meal?
No. Everything you eat is absorbed; the question is how much is used for building muscle at once. The evidence points to about 0.4 g/kg per meal, which for most adults is 25 to 40 g, repeated three or four times a day.6
Do I need protein powder?
No. Powder is a convenience, not a requirement. The ISSN notes that whole foods should be the main source and supplements are useful when it is impractical to eat enough from food.3 If a shake is what gets you from 70 g to 120 g on a busy day, it does the job.
How much protein should a 70 kg person eat?
At least 56 g a day to meet the RDA.1 If you train, are losing weight or are over 65, aim higher: 84 g at 1.2 g/kg, 112 g at 1.6 g/kg, 140 g at 2.0 g/kg.
How Calobook uses this
Calobook sets your daily protein target from your body weight, goal and activity during setup, then shows how much is left after every meal. The fit score checks each meal against that target, and the weekly check-in keeps protein high when calories come down so that what you lose is fat, not muscle.
Snap, scan or type a meal and see protein, calories and the rest in seconds, against a target built for your body.
Sources
- National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005), chapter 10, Protein and Amino Acids.
- European Food Safety Authority. Scientific Opinion on Dietary Reference Values for protein EFSA Journal, 2012.
- Jäger R, et al. International Society of Sports Nutrition Position Stand: protein and exercise Journal of the International Society of Sports Nutrition, 2017.
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults British Journal of Sports Medicine, 2018.
- Bauer J, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group Journal of the American Medical Directors Association, 2013.
- Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution Journal of the International Society of Sports Nutrition, 2018.
- Westerterp KR. Diet induced thermogenesis Nutrition and Metabolism, 2004.
- Devries MC, et al. Changes in kidney function do not differ between healthy adults consuming higher- compared with lower- or normal-protein diets: a systematic review and meta-analysis Journal of Nutrition, 2018.
- Ikizler TA, et al. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update American Journal of Kidney Diseases, 2020.
- US Department of Agriculture. FoodData Central
This article is general nutrition information written by the Calobook team from the sources listed above. It is not medical advice and does not replace a consultation with a doctor or registered dietitian. If you are pregnant, breastfeeding, under 18, or managing a medical condition, talk to a professional before changing your diet. Last reviewed October 17, 2026.