Most adults need at least 0.36 grams of protein per pound of body weight per day. That’s the official Recommended Dietary Allowance, and for a 160-pound person, it works out to about 58 grams. But that number is a minimum to prevent deficiency, not an optimal target, and most active people need significantly more.
The Baseline: 0.36 Grams per Pound
The RDA of 0.36 grams per pound (0.8 grams per kilogram) was set to meet the basic needs of 97.5% of the healthy adult population. It keeps you from losing muscle in a sedentary lifestyle, but it wasn’t designed for people who exercise, want to build muscle, or are trying to lose fat. Think of it as the floor, not the ceiling.
For a sense of scale: a 140-pound sedentary adult meets this minimum with about 50 grams of protein a day. That’s roughly one chicken breast and a cup of Greek yogurt. Most Americans already exceed the RDA without trying, so protein deficiency is rare in developed countries. The more useful question is how much protein actually helps you reach a specific goal.
Building Muscle: 0.7 to 1.0 Grams per Pound
If you’re strength training and want to add muscle, the research points to a clear sweet spot. A large meta-analysis published in the British Journal of Sports Medicine found that protein intake beyond 1.62 grams per kilogram per day (about 0.73 grams per pound) produced no additional gains in fat-free mass for people doing resistance training. For a 180-pound person, that’s roughly 132 grams per day.
However, because individual responses vary, the same researchers noted the confidence interval stretched up to 2.2 grams per kilogram (1.0 gram per pound). If you want to play it safe and maximize your chances, aiming for 0.7 to 1.0 grams per pound covers the full range supported by evidence. A separate systematic review in Nutrition Reviews confirmed this pattern: gains in lean body mass increased steeply up to about 1.3 grams per kilogram (0.59 grams per pound), then the rate of benefit dropped sharply. Resistance training helped people continue gaining muscle at higher intakes, but the returns kept diminishing.
In practical terms, if you weigh 170 pounds and lift weights three to four times a week, shooting for 120 to 170 grams of protein daily puts you squarely in the effective range. Going above 1.0 gram per pound is unlikely to hurt, but unlikely to help your muscles grow faster either.
Losing Weight: 0.7 to 1.0 Grams per Pound
When you’re eating fewer calories than you burn, your body doesn’t just pull energy from fat. It also breaks down muscle tissue, which slows your metabolism and leaves you weaker. Protein is your main defense against this. Guidelines for preserving muscle during weight loss recommend approximately 0.7 to 1.0 grams of protein per pound of body weight. A 150-pound person cutting calories would aim for 105 to 150 grams of protein daily.
This is notably higher than the RDA, and for good reason. In a caloric deficit, your body’s demand for amino acids rises because it’s under metabolic stress. Higher protein also helps with satiety, making it easier to stick with a calorie target without feeling starved between meals.
Endurance Athletes: 0.55 to 0.64 Grams per Pound
Runners, cyclists, and swimmers don’t need quite as much protein as strength athletes, but they still need more than the RDA. Sports nutrition guidelines recommend 1.2 to 1.4 grams per kilogram (0.55 to 0.64 grams per pound) for endurance athletes. If you’re also trying to lose body fat while training, that number goes up to about 0.9 grams per pound to protect muscle tissue.
Spreading your intake across meals matters here. Aiming for roughly 0.25 to 0.3 grams per pound at each meal or snack helps your body use the protein more efficiently for repair, rather than oxidizing it all for energy at once.
Adults Over 50: 0.54 to 0.72 Grams per Pound
Muscle loss accelerates with age. After 50, you lose roughly 1% to 2% of muscle mass per year if you don’t actively work against it, a process called sarcopenia. Older adults also become less efficient at using dietary protein to build and repair muscle, so the same intake that works for a 30-year-old won’t cut it.
Stanford Lifestyle Medicine recommends adults over 50 consume 0.54 to 0.72 grams per pound per day (1.2 to 1.6 grams per kilogram). For those over 65, some research pushes the upper end even higher, to 0.9 grams per pound. A 155-pound person in their 60s would target roughly 84 to 112 grams per day as a starting point, potentially more if they’re active.
During Pregnancy
Pregnant women need a minimum of 60 grams of protein per day, which should make up about 20% to 25% of total calorie intake. That figure applies across pregnancy, though needs increase in the second and third trimesters as the baby grows. For most women, this works out to somewhat above the standard RDA but below what athletes need.
Upper Limits and Safety
For the average healthy person who isn’t a competitive athlete or serious bodybuilder, Harvard Health suggests capping total protein at about 2 grams per kilogram of ideal body weight, or roughly 0.9 grams per pound. For a 140-pound person, that’s around 125 grams per day.
Very high protein diets carry some risks depending on where the protein comes from. People eating large amounts of protein have a higher rate of kidney stones. Diets heavy in red meat and saturated fat are linked to increased risk of heart disease and colon cancer. But a high-protein diet built around plant sources, poultry, fish, and dairy doesn’t appear to carry the same risks. The source of your protein matters as much as the quantity.
If you have existing kidney disease, high protein intakes can accelerate damage. Otherwise, for healthy kidneys, intakes up to 1.0 gram per pound have not been shown to cause harm in research spanning several months to over a year.
Quick Reference by Goal
- Sedentary adult (minimum): 0.36 grams per pound
- Adults over 50: 0.54 to 0.72 grams per pound
- Endurance athletes: 0.55 to 0.64 grams per pound
- Muscle building: 0.7 to 1.0 grams per pound
- Weight loss (preserving muscle): 0.7 to 1.0 grams per pound
- Upper limit for most people: ~0.9 grams per pound
Your ideal number depends on your body weight, activity level, and goal. If you’re active in any meaningful way, the RDA of 0.36 grams per pound is almost certainly too low. For most people who exercise and want to stay strong, somewhere between 0.7 and 1.0 grams per pound covers the range where real benefits happen.