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, set as the Recommended Dietary Allowance, represents the minimum to prevent deficiency in a sedentary adult. It’s not necessarily the optimal amount, and depending on your age, activity level, and goals, you may benefit from significantly more.
The Baseline for Sedentary Adults
The RDA of 0.8 grams per kilogram of body weight (0.36 grams per pound) is designed to meet the basic needs of 97.5% of healthy, inactive adults. For a few common body weights, that translates to:
- 130 pounds (59 kg): ~47 grams per day
- 150 pounds (68 kg): ~55 grams per day
- 180 pounds (82 kg): ~65 grams per day
- 200 pounds (91 kg): ~73 grams per day
These numbers keep you out of trouble, but they were established to prevent deficiency, not to optimize body composition, recovery, or long-term health. Most nutrition researchers now consider the RDA a floor rather than a target.
If You Exercise Regularly
Physical activity increases protein turnover in your muscles, so active people need more. The range depends on the type of exercise. People who do regular cardio or moderate exercise benefit from about 1.1 to 1.5 grams per kilogram daily (0.5 to 0.68 grams per pound). If you lift weights or train for endurance events like distance running or cycling, that range shifts to 1.2 to 1.7 grams per kilogram (0.55 to 0.77 grams per pound).
For a 170-pound person who lifts weights, this means roughly 93 to 131 grams of protein per day. Intakes above 2 grams per kilogram (0.91 grams per pound) are generally considered excessive for most exercisers, with diminishing returns beyond that point.
If You’re Trying to Lose Weight
Protein becomes especially important when you’re eating fewer calories than you burn. In a caloric deficit, your body is more likely to break down muscle for energy. Eating more protein helps preserve lean mass while you lose fat, and it keeps you feeling fuller between meals.
Research on athletes cutting weight suggests a range of 1.6 to 2.4 grams per kilogram per day (0.73 to 1.09 grams per pound). Above 2.4 grams per kilogram, there doesn’t appear to be a meaningful additional muscle-sparing benefit. For someone who weighs 160 pounds and is actively dieting, that’s roughly 117 to 175 grams per day. Even if you’re not an athlete, aiming for the lower end of this range gives you better results than sticking with the standard RDA during weight loss.
If You’re Over 65
Nearly half the protein in your body is found in muscle tissue, and muscle mass naturally declines with age. This gradual loss, called sarcopenia, accelerates after 65 and increases the risk of falls, fractures, and loss of independence. Older adults process protein less efficiently, which means they need more of it to achieve the same muscle-building effect as a younger person.
Current recommendations for adults over 65 are 1.0 to 1.2 grams per kilogram per day (0.45 to 0.55 grams per pound). For a 155-pound older adult, that’s about 70 to 84 grams daily, roughly 30 to 50% more than the general RDA. The one exception: people with kidney disease should work with their care team on protein targets, since higher intake can accelerate kidney function decline when kidneys are already compromised.
During Pregnancy and Breastfeeding
Protein needs increase during pregnancy, but the increase is modest in the first trimester and climbs significantly toward the end. In the first trimester, you need only about 1 extra gram of protein per day above your baseline. By the second trimester, that rises to roughly 6 to 9 additional grams. In the third trimester, when fetal growth is fastest, the additional need jumps to about 17 to 31 grams per day, depending on which set of guidelines you follow.
During breastfeeding, the extra protein requirement is about 19 to 23 grams per day for the first several months, tapering slightly after six months. For most women, this means a total daily intake somewhere in the range of 75 to 100 grams during late pregnancy and early lactation.
How to Spread It Across the Day
Your body can only use so much protein at once for muscle repair and growth. Eating 25 to 40 grams of protein per meal appears to be the practical sweet spot for most adults. Below about 20 grams, you may not hit the threshold of key amino acids needed to trigger muscle repair effectively. This is particularly relevant for older adults, who appear to need about 3 grams of the amino acid leucine per meal to fully activate muscle protein synthesis, and most 20-gram servings of protein only contain about 2 grams of leucine.
The practical takeaway: rather than loading all your protein into one large dinner, distributing it relatively evenly across three or four meals tends to give your muscles more opportunities to rebuild throughout the day. A breakfast of eggs and yogurt, a lunch with chicken or beans, and a dinner with fish or tofu gets most people into a good range without supplementation.
Not All Protein Sources Are Equal
Protein quality varies depending on how well your body can digest and use the amino acids in a given food. Animal sources like dairy, eggs, meat, and fish score highest on protein quality scales. Dairy proteins, for instance, score 100 to 120 on the digestibility scale used by the food science community, while soy scores around 84 to 89, peas around 62, and wheat as low as 45.
This doesn’t mean plant proteins are useless. It means you may need to eat a bit more total protein or combine different plant sources to get the same effect. Pairing grains with legumes (rice and beans, for example) covers the amino acid gaps that each has individually. If you eat a fully plant-based diet and you’re aiming for muscle maintenance or growth, targeting the higher end of the recommended ranges helps compensate for the lower digestibility scores.
Can You Eat Too Much Protein?
For people with healthy kidneys, high-protein diets don’t appear to cause kidney damage. A large study of women found no association between high protein intake and declining kidney function in those who started with normal kidneys. The concern is real, however, for people who already have reduced kidney function, even mild levels. In that group, diets heavy in animal protein were linked to faster decline.
Intakes beyond about 2 grams per kilogram of body weight per day are generally considered excessive and offer little additional benefit for most people. At very high levels, protein simply displaces other nutrients in your diet, potentially leaving you short on fiber, healthy fats, or micronutrients from fruits and vegetables. For the vast majority of people, the risk isn’t eating too much protein. It’s not eating enough, particularly among older adults and people who are dieting.