Most adults need at least 0.36 grams of protein per pound of body weight per day, which works out to about 55 grams for a 150-pound person. That number is the official Recommended Dietary Allowance (RDA), but it represents a minimum to prevent deficiency, not necessarily an optimal intake. Depending on your age, activity level, and goals, you likely need more.
The Baseline for Average Adults
The RDA of 0.8 grams per kilogram of body weight (0.36 grams per pound) is designed for generally healthy, sedentary adults. For a 165-pound person, that comes to roughly 60 grams of protein a day. This amount keeps your body functioning and prevents muscle wasting under normal conditions, but many nutrition researchers consider it a floor rather than a target.
Most healthy people can safely eat up to 2 grams per kilogram of body weight, which for a 150-pound person is about 135 grams a day. Consuming more than about 0.9 grams per pound (around 150 grams daily for a 165-pound person) is where potential downsides start to appear, particularly extra strain on the kidneys over time. So for most people, the practical range falls somewhere between the RDA floor and that upper ceiling.
If You’re Trying to Build Muscle
Protein needs increase significantly when you’re doing regular strength training. A large meta-analysis published in the British Journal of Sports Medicine found that muscle gains from resistance training plateau at a total daily intake of about 1.6 grams per kilogram (0.73 grams per pound). Beyond that threshold, extra protein didn’t produce additional muscle growth in healthy adults. For a 170-pound person, that translates to roughly 125 grams a day.
Some researchers place the upper useful range at 2.2 grams per kilogram for people training hard, but the evidence for benefits above 1.6 grams per kilogram is thin. If you’re lifting weights consistently and want a simple target, aiming for 0.7 to 0.8 grams per pound of body weight covers the vast majority of what your muscles can use.
If You’re Trying to Lose Weight
Protein becomes especially important during a calorie deficit because it helps preserve muscle mass while you lose fat, and it keeps you feeling full longer than carbohydrates or fat do. A study from the Carle Illinois College of Medicine found that dieters who increased their protein intake to about 80 grams per day (along with boosting fiber to 20 grams) had better weight-loss outcomes. For many people cutting calories, that 80-gram mark is a reasonable starting point, though those who are heavier or more active will benefit from more.
When you’re in a calorie deficit, your body is more likely to break down muscle for energy. Eating closer to 1.2 to 1.6 grams per kilogram helps counteract that effect, especially if you’re also exercising.
Protein Needs After Age 50
Adults over 50 face a gradual loss of muscle mass that accelerates with each passing decade. This process, called sarcopenia, contributes to falls, fractures, and loss of independence. Despite these higher stakes, nearly half of adults over 51 don’t meet even the basic protein recommendation. A study in the Journal of Nutrition, Health & Aging that examined the diets of nearly 12,000 older individuals found that roughly 46% fell short.
Older adults generally need more protein than younger adults because aging muscles become less efficient at using dietary protein. Many geriatric nutrition experts recommend 1.0 to 1.2 grams per kilogram as a better daily target for this age group. Combining higher protein intake with resistance exercise produces the most improvement in both muscle mass and strength.
During Pregnancy and Breastfeeding
Protein needs rise progressively throughout pregnancy. In the first trimester, the increase is negligible, just 1 gram above your normal intake. By the second trimester, you need an additional 9 to 10 grams per day, and by the third trimester, you need roughly 28 to 31 extra grams daily. For a woman who normally needs 50 grams, that means a third-trimester target of about 78 to 81 grams.
During breastfeeding, the additional requirement is around 19 grams per day for the first six months, dropping to about 13 grams per day after that as your baby starts eating solid foods.
How to Spread Protein Across Your Day
Your body can only use so much protein at once for building and repairing muscle. Research suggests that 20 to 25 grams of high-quality protein per meal is the minimum needed to trigger a meaningful muscle-building response. Eating more than that in a single sitting isn’t wasted (your body still uses it for energy and other functions), but the muscle-building benefit per gram starts to diminish.
A practical approach is to aim for about 0.4 grams per kilogram of body weight at each of four meals throughout the day. For a 155-pound person, that’s roughly 28 grams per meal, which adds up to about 112 grams daily. This even distribution tends to be more effective for maintaining muscle than loading most of your protein into a single large dinner, which is the pattern many people default to.
Plant-Based Protein Considerations
If you get most or all of your protein from plants, the total grams on a nutrition label don’t tell the full story. Animal proteins contain all essential amino acids in proportions your body can readily use, and they score higher on digestibility tests. Plant proteins, particularly from grains and legumes, tend to be lower in one or more essential amino acids and are slightly less digestible overall.
This doesn’t mean plant-based diets can’t meet your protein needs. It does mean you may want to aim for the higher end of any recommended range and eat a variety of protein sources throughout the day. Combining legumes with grains, or adding soy-based foods (which have a more complete amino acid profile), helps fill in the gaps. If you’re vegan and strength training, targeting 1.8 to 2.0 grams per kilogram rather than 1.6 gives you a buffer for lower digestibility.
Quick Reference by Body Weight
- 130 lbs (59 kg): RDA minimum 47 g; active/muscle-building 86–95 g; safe upper limit ~118 g
- 150 lbs (68 kg): RDA minimum 54 g; active/muscle-building 99–109 g; safe upper limit ~136 g
- 170 lbs (77 kg): RDA minimum 62 g; active/muscle-building 112–124 g; safe upper limit ~154 g
- 200 lbs (91 kg): RDA minimum 72 g; active/muscle-building 132–146 g; safe upper limit ~182 g
These ranges assume a healthy person without kidney disease. The “active” range reflects the 1.6 grams per kilogram threshold supported by the strongest evidence for muscle maintenance and growth.