Most healthy 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, the Recommended Dietary Allowance (RDA), represents the minimum to prevent deficiency. Depending on your age, activity level, and goals, your actual needs could be two or three times higher.
The Baseline for Healthy Adults
The RDA of 0.8 grams per kilogram of body weight (0.36 grams per pound) is designed to meet the basic protein needs of 97.5% of healthy, sedentary adults. For a 165-pound person, that comes to roughly 60 grams per day. Federal dietary guidelines place protein’s share of total calories between 10% and 35% for adults 19 and older, giving you a wide range to work within depending on your other macronutrient preferences.
It’s worth understanding that the RDA is a floor, not a target. It tells you the minimum amount needed to avoid losing muscle over time in a sedentary person. Most nutrition researchers now consider it too low for people who exercise, are trying to lose weight, or are over 50.
How Exercise Changes the Math
If you work out regularly, your protein needs jump significantly. People who exercise consistently need about 1.1 to 1.5 grams per kilogram of body weight. If you lift weights or train for distance running or cycling events, that range increases to 1.2 to 1.7 grams per kilogram, roughly 0.55 to 0.77 grams per pound.
For a 170-pound person who lifts weights three or four times a week, that translates to about 93 to 131 grams of protein per day. Endurance athletes have a slightly different reason for needing more: prolonged cardio burns through amino acids for fuel, creating oxidative losses that need to be replaced on top of normal muscle repair. Factoring in those losses, endurance athletes may benefit from intakes around 1.8 grams per kilogram (about 0.82 grams per pound), which is at the higher end of most athletic recommendations.
Protein Needs After 50
Aging muscles become less efficient at using dietary protein to build and repair tissue. This phenomenon, sometimes called anabolic resistance, means older adults can need up to 60% more protein in a single meal to get the same muscle-building response as a younger person eating the same amount. The practical result is that the standard RDA of 0.36 grams per pound often isn’t enough to prevent gradual muscle loss in people over 50 or 60.
Most experts in aging and nutrition recommend older adults aim higher, closer to the ranges used for active adults. Combining higher protein intake with resistance exercise produces the best results for preserving muscle mass and strength. Spreading protein across all three meals rather than loading it into dinner also appears to help, since the body can only use so much at once to stimulate muscle repair.
How Much You Need During Weight Loss
When you’re eating fewer calories than you burn, your body doesn’t just pull energy from fat stores. It also breaks down muscle. Eating more protein is the most effective dietary strategy to limit that muscle loss. Recommendations for preserving lean mass during a caloric deficit are considerably higher than the baseline RDA: roughly 0.7 to 1.0 grams per pound of body weight. A 150-pound person cutting calories would aim for 105 to 150 grams of protein daily.
Protein also helps with the hunger side of weight loss. It’s the most satiating macronutrient, meaning it keeps you feeling full longer per calorie than fat or carbohydrates. This makes higher-protein diets easier to stick with over weeks and months, which is ultimately what determines whether a weight-loss plan works.
Pregnancy and Breastfeeding
Protein needs increase during pregnancy, but the increase is modest in early pregnancy and grows substantially as the baby develops. In the first trimester, you need barely any extra protein beyond your normal intake. By the second trimester, the additional requirement is around 9 to 10 grams per day. In the third trimester, when fetal growth accelerates, you need an extra 28 to 31 grams daily on top of your baseline.
During breastfeeding, the additional protein demand is about 19 to 23 grams per day in the first six months, tapering to roughly 12 to 13 grams per day after six months if you’re partially breastfeeding. For most women, this means a total daily intake somewhere in the range of 70 to 90 grams during late pregnancy and early breastfeeding.
How to Spread It Across Meals
Your body doesn’t stockpile amino acids the way it stores fat or carbohydrates. Eating 100 grams of protein at dinner and very little at breakfast means you’re missing opportunities for muscle repair earlier in the day. Research on muscle protein synthesis suggests that roughly 20 to 40 grams of protein per meal is the practical range for most people, with older adults likely benefiting from the higher end of that range. For older adults specifically, hitting about 3 grams of leucine (an amino acid abundant in eggs, dairy, meat, and soy) per meal appears important for triggering the muscle repair process effectively. A meal with 30 to 40 grams of high-quality protein typically provides that amount.
A simple approach: aim for a solid protein source at each of your three main meals rather than relying on one large serving. If your daily target is 120 grams, three meals with 30 to 35 grams each plus a protein-rich snack gets you there without any single meal feeling excessive.
Is Too Much Protein Dangerous?
For healthy people, high-protein diets are not known to cause medical problems. The longstanding concern that high protein intake damages kidneys has not held up in research on people with normal kidney function. That said, intakes above roughly 0.9 grams per pound of body weight (about 150 grams per day for a 165-pound person) push past what most evidence supports as beneficial, and the returns diminish well before that point for most people.
The situation is different if you have existing kidney disease, diabetes, or other chronic conditions. In those cases, the kidneys may struggle to clear the waste products generated when protein is broken down, and higher intakes can accelerate decline in kidney function.
Quick Reference by Body Weight
- 130-pound sedentary adult: 47 g/day (RDA minimum), 91–130 g/day if losing weight
- 150-pound regular exerciser: 75–103 g/day for general fitness, 105–150 g/day if cutting calories
- 170-pound strength athlete: 93–131 g/day for muscle building and recovery
- 180-pound endurance athlete: up to 147 g/day to cover exercise-related amino acid losses
- 165-pound older adult: aim well above the 60 g/day RDA minimum, ideally with resistance training
These ranges overlap because protein needs depend on multiple factors at once. Someone who is 60 years old, actively lifting weights, and trying to lose body fat sits at the intersection of three categories that all push protein needs upward. In that case, aiming for the higher end of the range, closer to 0.7 to 1.0 grams per pound, makes sense.