How many grams of protein in a day? Most healthy adults need 0.8 grams of protein per kilogram of body weight per day, which works out to about 0.36 grams per pound. For a 70 kg (154 lb) adult that is 56 grams a day.
That figure is the Recommended Dietary Allowance (RDA) in the Dietary Reference Intakes used in the United States and Canada, as listed in the Health Canada reference table. It is the amount that covers nearly all healthy people.
Your daily protein number by body weight
Multiply your weight in kilograms by 0.8. The table does that math for common body weights.
| Body weight (kg) | Body weight (lb) | Protein per day (g) |
|---|---|---|
| 50 | 110 | 40 |
| 60 | 132 | 48 |
| 70 | 154 | 56 |
| 80 | 176 | 64 |
| 90 | 198 | 72 |
| 100 | 220 | 80 |
Source: 0.8 g/kg RDA for adults 19 and older, Dietary Reference Intakes (Health Canada table); the arithmetic and pound conversions are ours.
The same table lists reference intakes of 56 g a day for men and 46 g a day for women aged 19 and older. Those are fixed values for reference body sizes, so your own weight-based number is the better guide.
The adult RDA has been essentially unchanged for more than 70 years, according to a review in the journal Advances in Nutrition. It was derived as the minimum intake needed to avoid losing body nitrogen, which makes it a floor for avoiding deficiency.
The estimated average requirement behind it is 0.66 g/kg. The RDA of 0.8 g/kg sits above that so it covers almost everyone.
Video: Ohio State Wexner Medical Center
How protein needs change at different life stages
The 0.8 g/kg value applies to adults. Children, pregnancy and lactation have their own reference values.
| Group | RDA (g/kg/day) |
|---|---|
| Children 4 to 8 years | 0.95 |
| Teens 14 to 18 years | 0.85 |
| Adults 19 and older | 0.80 |
| Pregnancy (all ages) | 1.1 |
| Lactation (all ages) | 1.3 |
Source: Dietary Reference Intakes, protein reference values (Health Canada table).
The American Heart Association says growing children and pregnant or lactating women need a little more protein per kilogram because their bodies are building tissue.
Older adults and people who exercise
The official RDA does not change after age 70. Researchers have questioned that: a 2018 perspective in Advances in Nutrition by Traylor, Phillips and colleagues proposed that older adults consume at least 1.2 g/kg a day, while noting that longer intervention trials are still needed.
For people who train, the International Society of Sports Nutrition says 1.4 to 2.0 g/kg a day is sufficient for most exercising individuals. That is roughly 1.75 to 2.5 times the RDA.
If you are weighing supplements alongside that, our look at creatine and hair loss covers what one study actually found.
What 56 grams looks like on a plate
The American Heart Association gives approximate amounts: an 8-ounce glass of milk has about 8 grams, a cup of yogurt about 11 grams, a 3-ounce piece of lean meat about 21 grams, and a cup of dry beans about 16 grams. Those four add up to 56 grams.
Eggs are another easy source, and we broke down how many grams of protein are in an egg separately.
Where the popular advice goes wrong
The gym rule of one gram per pound is 2.2 g/kg, almost three times the adult RDA. It falls just inside the exercising range above, so it suits some hard-training people but is too high a baseline for most.
More is not automatically better. The American Heart Association notes that extra protein often comes from meats high in saturated fat, which can raise LDL cholesterol, and that it can crowd out fruits and vegetables. Food rumors deserve the same scrutiny: we checked whether tomatoes cause inflammation and what the science says about seed oils.
The acceptable range for protein is 10 to 35 percent of daily calories, so the RDA sits at the bottom of the range.
The same Advances in Nutrition review converts that range into grams: for reference body weights of 57 kg for women and 70 kg for men, it equals 1.05 to 3.67 g/kg a day. The low end of that range is already above the 0.8 g/kg RDA.
You do not need to count every gram. The American Heart Association says most people can meet their needs with a variety of protein sources, favoring beans, lentils, nuts, seeds and soy, plus fish and some lean meat.
It also suggests aiming for 3-ounce servings of cooked poultry or meat per meal, and says healthy people can include up to a whole egg or equivalent daily.
This is general information, not a diet plan. Check with your doctor or a registered dietitian before changing your protein intake, especially during pregnancy or if you have a health condition.
Frequently asked questions
How many grams of protein per pound of body weight do I need?
About 0.36 grams per pound at the adult RDA, which is 0.8 g/kg divided by 2.2 pounds per kilogram. A 154-pound adult comes to roughly 56 grams a day.
Is 100 grams of protein a day too much?
It is above the RDA for most adults, but it is not unusual for an active person. For a 70 kg exerciser, the International Society of Sports Nutrition range of 1.4 to 2.0 g/kg works out to 98 to 140 grams a day. Ask your doctor if you have kidney disease or another condition.
Do I need more protein when losing weight?
The International Society of Sports Nutrition says resistance-trained people may need 2.3 to 3.1 g/kg a day to retain lean mass while eating fewer calories. That statement applies to trained people in calorie deficits, so check with a dietitian before using it as a personal target.
