Most people need between 0.36 and 1.0 gram of protein per pound of body weight per day, depending on their activity level, age, and goals. A 170-pound sedentary adult needs a minimum of about 61 grams daily, while that same person building muscle in the gym might need 120 to 150 grams. The right number for you depends on what your body is doing.
The Baseline: Sedentary Adults
The Recommended Dietary Allowance for protein is 0.36 grams per pound of body weight. That’s the minimum to prevent deficiency in a healthy adult who isn’t particularly active. For a 150-pound person, that works out to about 54 grams of protein a day. For a 200-pound person, it’s 72 grams.
This number is lower than most people expect, and many nutrition researchers consider it a floor rather than a target. It’s enough to keep you from losing muscle if you’re sitting at a desk all day, but it’s not optimized for anything: not fitness, not aging well, not recovering from illness. If you exercise, want to lose fat without losing muscle, or are over 65, you almost certainly need more.
Building Muscle and Strength Training
If your goal is muscle growth, the research converges on a range of 0.73 to 1.0 gram per pound of body weight per day. That’s the range most sports nutrition experts agree maximizes muscle protein synthesis, the process by which your body repairs and builds new muscle tissue after training. For a 150-pound person, that means roughly 109 to 150 grams of protein daily.
The International Society of Sports Nutrition recommends a slightly broader range of 0.64 to 0.91 grams per pound for most exercising individuals. There’s even some evidence that intakes above 1.36 grams per pound may help resistance-trained athletes lose fat, though the muscle-building benefits plateau well before that point. For most people lifting weights three to five days a week, aiming for around 0.8 to 1.0 gram per pound is a practical, well-supported target.
Losing Weight Without Losing Muscle
When you’re eating fewer calories than you burn, your body doesn’t just tap into fat stores. It can also break down muscle for energy. Protein intake is the single biggest dietary lever you have to prevent that.
During a caloric deficit, protein needs go up, not down. Research on athletes cutting weight recommends 0.73 to 1.1 grams per pound per day, with some studies on resistance-trained individuals suggesting up to 1.2 grams per pound. Beyond about 1.1 grams per pound, the additional muscle-sparing effect becomes negligible. So if you’re dieting and want to hold onto the muscle you have, aim for the higher end of the range: roughly 0.8 to 1.0 gram per pound is a solid target for most people in a deficit.
Endurance Athletes
Runners, cyclists, and swimmers don’t need quite as much protein as strength athletes, but they need more than sedentary adults. Sports nutrition guidelines recommend 0.55 to 0.64 grams per pound daily for endurance training. If you’re also trying to lean out while training for a race, pushing that to 0.64 to 0.91 grams per pound helps preserve muscle tissue while you drop body fat.
Adults Over 65
Aging muscles become less efficient at using dietary protein. Starting around age 50, you lose roughly 1 to 2 percent of your muscle mass per year, a process called sarcopenia. To slow this decline, researchers recommend older adults consume 0.45 to 0.55 grams per pound daily, a meaningful bump above the baseline RDA. For a 160-pound older adult, that translates to about 72 to 88 grams a day rather than the 58 grams the standard RDA would suggest.
Pregnancy and Breastfeeding
Protein needs increase gradually during pregnancy but not as dramatically as you might think. In the first trimester, the increase is negligible, just a gram or two above your normal intake. By the third trimester, you need an additional 17 to 31 grams per day on top of your baseline. European health guidelines put the overall target for late pregnancy at roughly 0.45 grams per pound of body weight per day.
During breastfeeding, the recommendation is about 0.55 grams per pound, or an extra 19 to 23 grams per day above what a non-lactating woman would need. This additional protein supports milk production without depleting your own muscle stores.
How to Spread Protein 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 about 30 to 45 grams of protein per meal. Eating 80 grams in one sitting doesn’t double the effect of eating 40 grams. The excess gets used for energy or other metabolic processes, but it won’t build more muscle than a moderate dose would.
The practical takeaway: distribute your protein across three to four meals, aiming for 30 to 45 grams each time. Space those meals roughly three to four hours apart. If you eat before bed, 30 to 40 grams of a slow-digesting protein (like casein from dairy, cottage cheese, or Greek yogurt) has been shown to support overnight muscle repair and boost metabolic rate during sleep.
Upper Limits and Safety
For most healthy people, keeping protein at or below about 0.91 grams per pound of ideal body weight is a reasonable ceiling. That’s approximately 125 grams a day for someone whose ideal weight is around 140 pounds. Very high protein diets are associated with a higher risk of kidney stones, and if much of that protein comes from red and processed meat, there are links to increased heart disease and colon cancer risk. High-protein diets built around plant sources, poultry, and fish don’t appear to carry the same risks.
If you have existing kidney disease, high protein intake can accelerate damage. Healthy kidneys handle higher protein loads without trouble, but the “more is always better” mindset doesn’t hold up past a certain point.
Quick Reference by Goal
- Sedentary adult: 0.36 g per pound
- Older adult (65+): 0.45–0.55 g per pound
- Endurance athlete: 0.55–0.64 g per pound
- Muscle building: 0.73–1.0 g per pound
- Fat loss (preserving muscle): 0.73–1.1 g per pound
- Pregnancy (third trimester): ~0.45 g per pound
- Breastfeeding: ~0.55 g per pound
To calculate your own target, multiply your body weight in pounds by the number that matches your goal. If you’re between categories (say, a 55-year-old who lifts weights), lean toward the higher recommendation. These ranges overlap intentionally because bodies, training loads, and goals vary.