Most adults need at least 0.36 grams of protein per pound of body weight per day, which works out to about 54 grams for a 150-pound person. That number is the bare minimum to prevent deficiency, though. Your actual target depends on your age, activity level, and goals, and for many people it should be significantly higher.
The Baseline: What “Enough” Actually Means
The Recommended Dietary Allowance for protein is 0.8 grams per kilogram of body weight, or 0.36 grams per pound. For a 180-pound person, that’s roughly 65 grams per day. This number was set to meet the needs of 97.5% of the healthy adult population, but it was designed to prevent deficiency, not to optimize health, body composition, or performance. Think of it as the floor, not the ceiling.
If you’re relatively sedentary, eating at or slightly above the RDA is usually fine. But if you exercise regularly, are trying to lose weight, or are over 65, that baseline likely isn’t enough.
Protein for Muscle and Strength
If you lift weights or do any kind of resistance training, your protein needs jump considerably. A large meta-analysis published in the British Journal of Sports Medicine, pooling data from 49 studies and over 1,800 participants, found that muscle gains from resistance training plateau at about 1.62 grams per kilogram of body weight per day (0.73 g/lb). Beyond that point, extra protein didn’t translate into more muscle.
However, because individual responses vary, the researchers noted the upper end of the confidence interval reached 2.2 g/kg/day (1 g/lb). If you’re serious about maximizing muscle growth, aiming for roughly 0.7 to 1 gram of protein per pound of body weight per day covers the full range where benefits have been observed. For a 170-pound person, that’s 120 to 170 grams daily.
Protein for Weight Loss
When you eat fewer calories than you burn, your body doesn’t just pull energy from fat. It also breaks down muscle. Getting enough protein is the single most effective dietary strategy to minimize that muscle loss while you slim down.
Research in Advances in Nutrition confirms that eating below the RDA during a calorie deficit accelerates the loss of lean mass, at a rate of roughly 0.2 to 0.5% per week. Higher protein intakes help preserve muscle during weight loss, which matters because muscle is metabolically active tissue that keeps your resting metabolism higher. Most weight-loss studies showing good muscle retention use protein intakes in the range of 1.2 to 1.6 g/kg/day (0.55 to 0.73 g/lb).
Protein also helps with hunger. It’s the most satiating macronutrient, meaning it keeps you feeling full longer than the same number of calories from carbs or fat. That alone can make a calorie deficit easier to stick with.
Protein Needs After Age 65
Aging muscles become less responsive to protein. The same meal that triggers robust muscle repair in a 30-year-old produces a weaker response in a 70-year-old. This “anabolic resistance” is a major driver of sarcopenia, the gradual loss of muscle mass and strength that accelerates after 65.
Current expert recommendations for older adults range from 1.2 to 2.0 g/kg/day depending on health status. Older adults dealing with acute or chronic illness generally need 1.2 to 1.5 g/kg/day, while those with serious illness, injury, or malnutrition may need up to 2.0 g/kg/day. A recent study using precise amino acid tracking found that older adults with sarcopenia needed about 1.5 g/kg/day just to meet their baseline requirements. For a 150-pound older adult, that translates to roughly 100 grams per day rather than the 54 grams the standard RDA would suggest.
Protein During Pregnancy
Protein needs increase as pregnancy progresses, but the first trimester barely changes anything. Both the WHO and European food safety authorities recommend about 1 extra gram per day in the first trimester, roughly 9 additional grams in the second trimester, and 28 to 31 additional grams in the third trimester. That third-trimester bump is substantial. A woman who normally needs around 50 grams per day would need closer to 80 grams in late pregnancy.
How to Spread It Across Meals
Your body can only use so much protein at once for muscle repair. Research consistently shows that about 30 grams of protein per meal is enough to maximally stimulate muscle building in younger adults. Eating 60 grams in one sitting doesn’t double the response. For older adults, that threshold is higher, closer to 30 to 45 grams per meal, because their muscles need a stronger signal to kick-start the repair process.
The key amino acid driving this response is leucine, which acts as a trigger for your muscle-building machinery. Younger adults need about 2 grams of leucine per meal to flip that switch, while older adults likely need around 3 grams. You don’t need to track leucine specifically. If you’re getting 30 or more grams of high-quality protein per meal from sources like eggs, meat, fish, dairy, or soy, you’ll hit that leucine threshold naturally.
Practically, this means spreading your protein across three or four meals works better than loading it all into dinner. If your target is 120 grams, three meals with 40 grams each will likely do more for your muscles than eating 20 grams at breakfast, 20 at lunch, and 80 at dinner.
Is Too Much Protein Dangerous?
The concern you’ll hear most often is kidney damage. For healthy people, this isn’t supported by evidence. High-protein diets are not known to cause kidney problems in people with normal kidney function. The confusion stems from the fact that people with existing kidney disease do need to limit protein, because their kidneys struggle to clear the waste products of protein metabolism. That’s a management strategy for a disease, not a risk that protein creates the disease in the first place.
If you have kidney disease, diabetes, or other chronic conditions, protein intake is something to discuss with your doctor. For everyone else, intakes up to 2.2 g/kg/day have been studied extensively without adverse effects.
Quick Reference by Body Weight
- 130 lbs (59 kg): RDA minimum 47 g, active/weight loss range 72–95 g, muscle-building range 95–130 g
- 150 lbs (68 kg): RDA minimum 54 g, active/weight loss range 82–110 g, muscle-building range 110–150 g
- 180 lbs (82 kg): RDA minimum 65 g, active/weight loss range 98–132 g, muscle-building range 132–180 g
- 200 lbs (91 kg): RDA minimum 73 g, active/weight loss range 109–146 g, muscle-building range 146–200 g
These ranges use 0.8 g/kg for the RDA, 1.2–1.6 g/kg for the active and weight-loss range, and 1.6–2.2 g/kg for muscle building. If you’re significantly overweight, using your goal body weight or lean body mass rather than your current weight gives a more accurate target.