Most adults need at least 0.36 grams of protein per pound of body weight each day. For a 150-pound person, that works out to about 54 grams. But that baseline number, set by the Recommended Dietary Allowance, represents the minimum to prevent deficiency, not the amount that’s optimal for muscle, energy, or aging well. Depending on your activity level, age, and goals, you likely need more.
The Baseline: 0.36 Grams Per Pound
The RDA of 0.8 grams per kilogram of body weight (0.36 grams per pound) was designed for sedentary adults. It’s enough to keep your body functioning and prevent muscle wasting in the short term, but most nutrition researchers now consider it a floor rather than a target. If you exercise regularly, are over 65, are pregnant, or are trying to lose weight while preserving muscle, your needs are higher.
Here’s what the math looks like at the RDA level for different body weights:
- 130 lbs (59 kg): ~47 g/day
- 150 lbs (68 kg): ~54 g/day
- 180 lbs (82 kg): ~65 g/day
- 200 lbs (91 kg): ~73 g/day
If You Exercise Regularly
Physical activity increases protein demand because your muscles need amino acids to repair and grow after training. Endurance athletes, like runners and cyclists, do well with 1.2 to 1.4 grams per kilogram of body weight per day (about 0.55 to 0.64 grams per pound). For a 160-pound runner, that’s roughly 88 to 102 grams daily.
If you do resistance training or are actively trying to build muscle, the range shifts higher. Research suggests that 1.6 to 2.2 grams per kilogram per day (0.73 to 1.0 grams per pound) optimizes muscle building. A 180-pound person lifting weights would aim for roughly 131 to 180 grams per day. Going above 2.2 g/kg doesn’t appear to provide additional muscle-building benefit for most people.
Protein Needs After 65
Aging bodies become less efficient at using dietary protein to maintain muscle. This is one reason older adults lose muscle mass gradually, a process called sarcopenia that accelerates after 65. To counteract this, researchers recommend that older adults consume 1.0 to 1.2 grams per kilogram of body weight daily, which is 25 to 50 percent more than the standard RDA. For a 155-pound older adult, that means 70 to 84 grams of protein per day instead of the baseline 56 grams.
During Pregnancy and Breastfeeding
Protein needs rise substantially during pregnancy and lactation to support fetal growth and milk production. The recommendation jumps from 0.8 g/kg to 1.1 g/kg per day, which translates to about 71 grams daily for most women. That’s roughly 25 extra grams compared to the standard recommendation, equivalent to adding a chicken breast or a cup of Greek yogurt plus an egg to your usual diet.
Why Protein Helps With Weight Loss
Protein is the most satiating macronutrient, meaning it keeps you feeling full longer than the same number of calories from carbohydrates or fat. It also has a higher thermic effect: your body burns more energy digesting protein than it does digesting other nutrients. Studies measuring this effect show that meals with 30% of calories from protein can produce a thermic effect around 9 to 11% of total calories consumed, meaning your body uses a meaningful chunk of those protein calories just to process them.
If you’re eating at a calorie deficit to lose weight, getting enough protein also protects against muscle loss. Many weight-loss diets aim for 25 to 30% of total calories from protein. On a 1,800-calorie diet, that’s 112 to 135 grams per day.
Spreading Protein Across Meals
Your body can only use so much protein at once for muscle repair. Research on younger adults suggests that 20 to 25 grams of protein per meal, eaten roughly every three to four hours, maximizes the muscle-building response. A more individualized guideline is 0.4 to 0.55 grams per kilogram of body weight per meal, spread across four meals. For a 170-pound person, that’s about 31 to 42 grams per meal.
This doesn’t mean protein beyond that threshold is wasted. Your body still uses it for energy, immune function, and other processes. But if your goal is building or maintaining muscle, front-loading all your protein into a single meal is less effective than distributing it throughout the day.
Not All Protein Sources Are Equal
Animal proteins generally contain all nine essential amino acids in proportions your body can use efficiently. Plant proteins often fall short on one or two amino acids, which means your body absorbs and uses a smaller percentage of the protein you eat. Researchers measure this with a digestibility score: whey protein scores 100 to 107 out of 100 (it’s highly bioavailable), soy protein scores 84 to 89, and pea protein scores around 62.
This doesn’t mean plant protein is bad. It means that if you rely primarily on plant sources, you’ll want to eat a bit more total protein and combine different sources throughout the day, such as pairing legumes with grains, to cover all your amino acid needs.
High-Protein Foods at a Glance
Animal Sources
- Chicken breast, skinless (3 oz): 28g
- Steak (3 oz): 26g
- Salmon or tuna (3 oz): 22g
- Greek yogurt (6 oz): 18g
- Cottage cheese (4 oz): 14g
- Egg, large (1): 6g
- Skim milk (1 cup): 8g
Plant Sources
- Pinto beans (½ cup): 11g
- Lentils (½ cup): 9g
- Edamame (½ cup): 9g
- Chickpeas (½ cup): 7g
- Pumpkin seeds (1 oz): 9g
- Peanut butter (1 Tbsp): 7g
- Almonds (1 oz): 6g
- Quinoa (½ cup): 4g
A practical day at 100 grams of protein might look like: two eggs at breakfast (12g), Greek yogurt as a snack (18g), a chicken breast with quinoa at lunch (32g), and salmon with a half cup of black beans at dinner (30g). That’s 92 grams before accounting for the smaller amounts of protein in bread, vegetables, and other foods that add up across the day.
Can You Eat Too Much Protein?
For people with healthy kidneys, there’s no strong evidence that high protein intake (even above 2.0 g/kg) causes kidney damage. However, if you already have kidney disease, high protein intake can worsen kidney function because the kidneys struggle to clear the extra waste products from protein metabolism. If you have impaired kidney function, your protein intake should be guided by your doctor.
For most healthy adults, the practical ceiling isn’t really about safety. It’s about diminishing returns: eating beyond 2.2 g/kg per day doesn’t build more muscle, and those extra calories from protein could be spent on other nutrients your body needs. Extremely high protein diets can also crowd out fiber, healthy fats, and micronutrients if you’re not careful about food variety.