How much protein do I need a day?
In short
- The RDA is 0.8 g of protein per kg of body weight (0.36 g per lb), a minimum for people who do not train.
- People who lift need 1.4-2.0 g per kg (0.6-0.9 g per lb), toward the top of that range when losing fat.
- Above about 1.6 g per kg, extra protein adds little muscle according to a meta-analysis of 49 studies.
- The easiest way to hit your target is 25-40 g of protein in each meal.
Most adults need at least 0.8 g of protein per kilogram of body weight a day (0.36 g per pound), the Recommended Dietary Allowance set by the Institute of Medicine. If you lift weights, you need more: 1.4-2.0 g per kg (0.6-0.9 g per lb) according to the International Society of Sports Nutrition (2017). When losing fat, aim toward the top of that range. The protein calculator gives your exact number.
Daily protein targets
| Situation | Per kg of body weight | Per lb | For 70 kg (154 lb) |
|---|---|---|---|
| No training, minimum | 0.8 g | 0.36 g | 56 g |
| Regular strength training | 1.4-2.0 g | 0.6-0.9 g | 98-140 g |
| Fat loss with training | 1.8-2.2 g | 0.8-1.0 g | 126-154 g |
| Muscle gain | 1.6-2.0 g | 0.7-0.9 g | 112-140 g |
If you carry a lot of extra weight, use your goal weight instead of your current weight. Otherwise the number comes out too high.
How much protein to build muscle
A meta-analysis by Morton and colleagues (2018) combined 49 studies with 1,863 people doing resistance training. Extra protein increased muscle gain up to about 1.6 g per kg a day, and beyond that the benefit almost flattened. The upper end of the confidence interval was about 2.2 g per kg.
So 1.6 g per kg is enough for most people, and 2.0-2.2 g makes sense when dieting or if you want a safety margin. Above that, extra protein simply becomes extra calories.
Why protein matters for fat loss
Protein does two jobs in a calorie deficit. It protects muscle while the body looks for energy, and it keeps you full longer than carbs or fat. A review by Leidy and colleagues (2015) found that higher-protein diets of about 1.2-1.6 g per kg helped people lose weight and keep it off better than normal-protein diets.
That is why protein should go up, not down, when you cut calories. How to set the deficit itself is in calorie deficit: how to calculate it.
High-protein foods
Values per 100 g of cooked food from USDA FoodData Central. Full nutrition facts for each are on the food calories pages.
| Food | Protein per 100 g | Calories per 100 g |
|---|---|---|
| Braised beef | 32.4 g | 191 kcal |
| Roasted chicken breast | 31 g | 165 kcal |
| Roasted turkey | 29.1 g | 159 kcal |
| Cooked shrimp | 24 g | 99 kcal |
| Baked pollock | 23.5 g | 111 kcal |
| Canned tuna | 19 g | 90 kcal |
| Tofu | 17.3 g | 144 kcal |
| Hard-boiled egg | 12.6 g | 155 kcal |
| Cottage cheese 4% | 11.1 g | 98 kcal |
| Cooked lentils | 9 g | 116 kcal |
Fish, shrimp, poultry and cottage cheese give the most protein per calorie. Beans and lentils give less protein but add fibre.
How to hit your protein target
A target of 120-140 g looks big until you split it across meals. Three meals of 30-40 g and one snack of 20 g get you there.
- Breakfast: 3 eggs and 150 g (5 oz) of cottage cheese, about 36 g of protein.
- Lunch: 150 g (5 oz) of chicken breast with rice, about 50 g.
- Snack: a cup of kefir or Greek yogurt and a handful of almonds, about 16-20 g.
- Dinner: 150 g (5 oz) of white fish or a can of tuna with vegetables, about 30-35 g.
Protein powder is handy when real food is not around, but it is optional. Use it only if food alone falls short.
Bottom line
Work out your daily target, split it across 3-4 meals and fix the meal that has the least protein first. For most people that is breakfast.
Tonus sets your protein target from your goal and updates it with your weight: higher when you lose fat, lower when you maintain. The food diary shows protein eaten against the target, and you can log a meal with a photo or by voice.
Frequently asked questions
How much protein do I need to build muscle?
About 1.6 g per kg of body weight (0.7 g per lb) covers most people who lift. Going up to 2.2 g per kg is fine, but research shows little extra muscle above 1.6 g.
How much protein can the body absorb at once?
There is no hard limit of 30 g. All protein gets absorbed, larger meals just take longer. For muscle growth, spreading protein over 3-4 meals of 0.3-0.4 g per kg works well.
Is high protein bad for your kidneys?
Not in healthy people: a 2018 meta-analysis by Devries and colleagues found that diets with 1.5 g per kg or more did not harm kidney function. People with kidney disease should follow their doctor's advice.
Sources
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press, 2005 nap.nationalacademies.org/catalog/10490
- Jäger R. et al. International Society of Sports Nutrition Position Stand: protein and exercise. JISSN, 2017 doi.org/10.1186/s12970-017-0177-8
- Morton R. W. 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. Br J Sports Med, 2018 doi.org/10.1136/bjsports-2017-097608
- Leidy H. J. et al. The role of protein in weight loss and maintenance. Am J Clin Nutr, 2015 doi.org/10.3945/ajcn.114.084038
- Devries M. C. et al. Changes in kidney function do not differ between healthy adults consuming higher- compared with lower- or normal-protein diets. J Nutr, 2018 doi.org/10.1093/jn/nxy197
This article is for general information and does not replace medical advice.