Most healthy adults need at least 0.8 grams of protein per kilogram of body weight per day, which works out to about 0.36 grams per pound. For a 150-pound person, that’s roughly 54 grams; for someone weighing 180 pounds, about 65 grams. But that baseline number is a minimum to prevent deficiency, not necessarily the amount that keeps you in optimal health. Your actual needs depend on your age, activity level, and goals.
The Baseline: 0.8 Grams Per Kilogram
The Recommended Dietary Allowance of 0.8 g/kg was set to cover the basic protein needs of nearly all sedentary adults. It’s the amount required to maintain nitrogen balance, meaning your body isn’t breaking down more protein than it’s taking in. Most people who eat a standard mixed diet meet or exceed this number without trying.
That said, many nutrition researchers now view 0.8 g/kg as a floor rather than a target. The Chinese Nutrition Society, for instance, updated its general recommendation in 2023 to 1.0–1.2 g/kg per day, reflecting a growing body of evidence that slightly higher intakes support better muscle maintenance, bone health, and metabolic function over time.
How Exercise Changes the Number
If you’re physically active, 0.8 g/kg won’t cut it. People who exercise regularly, whether running, swimming, cycling, or doing group fitness classes, generally need about 1.1 to 1.5 grams per kilogram. If you lift weights or train seriously for endurance events, that range shifts up to 1.2 to 1.7 g/kg. For a 170-pound person lifting weights several times a week, that translates to roughly 93 to 131 grams of protein per day.
There’s a ceiling, though. Research on muscle-related outcomes shows diminishing returns above about 1.6 to 1.9 g/kg per day. Intakes above 2 g/kg are generally considered excessive for most people, offering little additional benefit for muscle growth or performance while simply adding calories. So doubling or tripling your protein intake beyond what your body can use doesn’t build more muscle; it just gets burned for energy or stored.
Protein Needs After 65
Adults over 65 face a challenge: the body becomes less efficient at using dietary protein to build and repair muscle. This makes age-related muscle loss, known as sarcopenia, a real concern. Losing muscle doesn’t just mean losing strength. It increases fall risk, limits independence, and raises the likelihood of hospitalization.
Despite this, the official RDA for older adults remains the same 0.8 g/kg set for younger people. Researchers who study aging and nutrition consistently recommend higher intakes: 1.0 to 1.2 g/kg per day at minimum, with some evidence supporting up to 1.3 g/kg for those who are already frail or recovering from illness. For a 160-pound older adult, that means aiming for roughly 73 to 87 grams daily rather than the 58 grams the RDA would suggest.
Protein During Weight Loss
When you cut calories to lose weight, your body doesn’t just burn fat. It also breaks down muscle for energy, especially if protein intake drops too low. Eating more protein during a caloric deficit helps preserve lean mass, which matters because muscle tissue drives your resting metabolism. Lose too much of it, and keeping weight off becomes harder over time.
A review published in The Journals of Gerontology found that older adults in particular benefit from 1.0 to 1.6 g/kg daily during weight loss to maintain muscle strength. For a 180-pound person, that’s roughly 82 to 130 grams per day. Even if you’re younger, bumping protein toward the higher end of your recommended range during a diet is a practical way to stay fuller longer and protect the muscle you already have.
Pregnancy and Breastfeeding
Protein needs increase during pregnancy, but the increase is surprisingly small in the first trimester: only about 1 to 5 extra grams per day beyond your normal intake. The jump comes later. In the second trimester, you need roughly 6 to 9 additional grams daily, and by the third trimester, that rises to 17 to 31 extra grams per day depending on which set of international guidelines you follow.
During breastfeeding, the extra demand stays elevated at about 19 to 23 additional grams per day for the first few months, gradually decreasing to around 12 to 13 extra grams after six months. These additions sit on top of whatever your baseline needs would otherwise be.
When You Eat Matters Too
Spreading your protein across three meals is more effective than loading most of it into dinner, which is what many people do. A study in The Journal of Nutrition compared two groups eating the same total protein: one split it evenly across breakfast, lunch, and dinner (about 30 grams each), while the other skewed heavily toward the evening meal (roughly 10 grams at breakfast, 16 at lunch, and 63 at dinner). The group that spread their intake evenly had 25% higher muscle protein synthesis over 24 hours.
The practical takeaway: aim for at least 25 to 30 grams of protein at each meal rather than eating toast for breakfast and making up the difference at dinner. A few eggs with toast gets you close to 20 grams. A palm-sized portion of chicken, fish, or beans at lunch and dinner easily covers the rest.
Not All Protein Sources Are Equal
Protein quality matters, and it’s measured by how well your body can digest and use the amino acids in a given food. Animal proteins like dairy and eggs score at the top. Whey protein concentrate, for example, scores 107 out of 100 on the digestibility scale used by the food science community (scores above 100 are possible because some proteins exceed the reference standard). Milk protein concentrate scores 120.
Plant proteins score lower. Soy protein isolate comes in around 84, soy flour at 89, and pea protein concentrate at 62. Wheat protein sits at just 45. This doesn’t mean plant proteins are inadequate, but it does mean that if you rely heavily on plant sources, you may need to eat a bit more total protein to get the same muscle-building effect. Combining different plant sources, like rice and beans, helps fill gaps in amino acid profiles.
Is Too Much Protein Bad for Your Kidneys?
This is one of the most common concerns, and for healthy people, the evidence is reassuring. A systematic review of both controlled trials and observational studies found that protein intakes well above the RDA had little or no effect on blood markers of kidney function in healthy adults. Higher protein diets did increase the kidneys’ filtration rate, but all measured rates remained within the normal range.
The key word is “healthy.” If you already have chronic kidney disease, higher protein intake can accelerate damage, and your intake should be guided by a specialist. But for people with normal kidney function, eating 1.2 to 1.6 g/kg per day poses no demonstrated risk based on current evidence.
Quick Reference by Body Weight
- 130 lbs (59 kg): RDA minimum 47 g, active range 65–100 g
- 150 lbs (68 kg): RDA minimum 54 g, active range 75–116 g
- 170 lbs (77 kg): RDA minimum 62 g, active range 85–131 g
- 200 lbs (91 kg): RDA minimum 73 g, active range 100–155 g
The “active range” covers regular exercisers through serious strength trainers at 1.1 to 1.7 g/kg. If you’re over 65 or losing weight, aim for at least the lower end of the active range even if you’re not particularly athletic.