The baseline recommendation for protein is 0.36 grams per pound of body weight per day. For a 170-pound person, that works out to about 61 grams. But this number represents the minimum to avoid deficiency, not the amount that’s optimal for building muscle, losing fat, or staying strong as you age. Most active people need significantly more.
Your ideal intake depends on what your body is doing: maintaining weight, building muscle, cutting fat, or simply keeping up with the demands of aging. Here’s what the evidence supports for each scenario.
The Baseline: 0.36 Grams per Pound
The Recommended Dietary Allowance (RDA) of 0.36 grams per pound (0.8 g/kg) is set for generally healthy, sedentary adults. It’s enough to meet basic physiological needs, support immune function, and prevent muscle wasting in someone who isn’t particularly active. If you weigh 150 pounds, that’s about 54 grams per day. At 200 pounds, it’s 72 grams.
For context, a chicken breast has roughly 30 grams and a cup of Greek yogurt has about 15. Most Americans already eat at or above this level without trying. The real question most people are asking isn’t whether they’re hitting the minimum. It’s how much more they need to reach their specific goal.
Building Muscle: 0.7 to 1.0 Grams per Pound
If you’re strength training and trying to gain muscle, you need roughly double the RDA or more. The range most supported by research falls between 0.7 and 1.0 grams per pound of body weight (1.6 to 2.2 g/kg). For a 180-pound person, that’s 126 to 180 grams per day.
Going above 1 gram per pound hasn’t shown meaningful additional benefits for muscle growth in most studies. The popular “1 gram per pound” rule is a simple ceiling that’s easy to remember, and it keeps you comfortably within the effective range even if your intake varies day to day. If you’re newer to lifting, the lower end of this range is likely sufficient since your body responds more readily to training stimulus early on.
Losing Fat Without Losing Muscle
Protein becomes even more important when you’re eating in a caloric deficit. Cutting calories puts your body in a state where it can break down muscle for energy, and higher protein intake is the most effective nutritional strategy to prevent that.
Research on athletes restricting calories by 40% illustrates this clearly. In one study, participants eating about 0.45 grams per pound (1.0 g/kg) lost 3.5 pounds of lean mass in just two weeks. Those eating roughly 1.0 gram per pound (2.3 g/kg) lost only 0.7 pounds of lean mass over the same period. In another trial, participants consuming about 1.1 grams per pound (2.4 g/kg) during a steep caloric deficit actually gained lean mass over four weeks while losing fat, while a lower-protein group simply maintained theirs.
Current recommendations for preserving muscle during weight loss fall between 0.7 and 1.1 grams per pound (1.6 to 2.4 g/kg). If you’re resistance training while dieting, which you should be, some research suggests going as high as 1.2 grams per pound (2.7 g/kg) can be beneficial. The more aggressive your calorie cut, the more protein you need to protect muscle tissue. There appears to be a ceiling around 1.1 grams per pound beyond which additional protein doesn’t offer further muscle-sparing effects for most people.
Endurance Athletes: A Different Range
Runners, cyclists, and swimmers don’t need quite as much protein as strength athletes, but they still need more than the baseline. The recommended range for endurance athletes is 0.55 to 0.64 grams per pound (1.2 to 1.4 g/kg). For a 150-pound runner, that’s roughly 82 to 96 grams daily.
This accounts for the muscle repair demands of sustained aerobic exercise. Long runs and rides cause micro-damage to muscle fibers, and adequate protein supports recovery between sessions. If you’re doing both endurance and strength work, aim closer to the strength training range.
Adults Over 50: Higher Needs Than You’d Expect
Aging muscles become less efficient at using dietary protein to build and repair tissue, a phenomenon researchers call “anabolic resistance.” This means older adults need more protein per meal and per day to get the same muscle-building response a younger person would.
The standard RDA of 0.36 grams per pound is increasingly considered inadequate for people over 50. Most experts in aging and nutrition recommend 0.5 to 0.7 grams per pound to slow age-related muscle loss. Pairing this with resistance exercise produces the strongest results for maintaining muscle mass and strength.
There is an upper limit worth noting. Intakes above roughly 0.9 grams per pound (about 150 grams per day for a 165-pound person) may carry risks, particularly for older adults. Staying within 0.5 to 0.7 grams per pound hits the sweet spot for most people in this age group.
How to Spread It Across the Day
Your body can only use so much protein at once for muscle repair. Research shows that muscle protein synthesis maxes out at around 30 to 45 grams per meal. Eating 80 grams in one sitting won’t double the muscle-building response compared to 40 grams. Those extra calories still count, but the muscle-building benefit plateaus.
A practical approach: divide your daily target across three to four meals, aiming for at least 30 grams at each. If your target is 150 grams per day, that could look like four meals with roughly 37 grams each. People who consistently hit 30 or more grams in at least one to two meals per day show better lean mass and muscle strength than those who concentrate their protein in a single meal, particularly as they age.
Is High Protein Safe?
For healthy people, high-protein diets have not been shown to cause kidney damage or other medical problems. This is one of the most persistent nutrition myths, and the evidence simply doesn’t support it. Your kidneys are designed to filter the byproducts of protein metabolism, and they handle elevated intakes without issue when they’re functioning normally.
The exception is people with existing kidney disease, diabetes, or other chronic conditions that affect kidney function. In those cases, the body may struggle to clear protein waste products efficiently, and a high-protein diet can accelerate kidney decline.
Quick Reference by Goal
- Sedentary adult (minimum): 0.36 g per pound
- Endurance athlete: 0.55 to 0.64 g per pound
- Muscle building: 0.7 to 1.0 g per pound
- Fat loss while preserving muscle: 0.7 to 1.1 g per pound
- Adults over 50: 0.5 to 0.7 g per pound
These ranges assume total body weight. If you carry a significant amount of body fat (above 30% or so), using your lean body mass or your goal weight as the basis for calculation will give you a more accurate target than plugging in your total weight.