Most healthy adults need at least 0.8 grams of protein per kilogram of body weight per day. For a 150-pound (68 kg) person, that works out to about 54 grams. But that number is a minimum to prevent deficiency, not necessarily what’s optimal. Your actual needs depend on your age, activity level, whether you’re trying to lose weight, and whether you’re pregnant or breastfeeding.
The Baseline for Healthy Adults
The international Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg of body weight, regardless of age. To find your minimum in grams, divide your weight in pounds by 2.2, then multiply by 0.8. A 180-pound person lands around 65 grams per day; a 130-pound person, about 47 grams.
This baseline keeps the average sedentary adult in positive nitrogen balance, meaning your body isn’t breaking down its own muscle to meet its needs. But most researchers now consider 0.8 g/kg a floor, not a target. People who exercise, are over 65, or are losing weight on purpose generally benefit from eating well above it.
If You Exercise Regularly
The International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg per day for most people who exercise, whether that’s running, cycling, or lifting weights. For a 170-pound person, that range is roughly 108 to 154 grams daily. The society frames this as a minimum recommended amount, noting that people who train hard may need even more.
If you’re dieting while trying to hold onto muscle, the numbers go higher still. Resistance-trained individuals cutting calories may need 2.3 to 3.1 g/kg per day to maximize lean mass retention. There’s even evidence that intakes above 3.0 g/kg can promote fat loss in people who lift regularly, though that level isn’t necessary for most.
How to Spread It Across Meals
Your body can only use so much protein at once for building muscle. Research in young adults suggests that roughly 20 to 25 grams of high-quality protein per meal maximally stimulates muscle repair and growth. Eating 60 grams in one sitting isn’t wasted (your body still uses the calories and amino acids), but it won’t double the muscle-building signal compared to a moderate portion.
A practical approach: aim for about 0.4 g/kg per meal spread across at least four eating occasions. For someone targeting 1.6 g/kg per day (a good middle ground for active people), that’s four meals each containing around 0.4 g/kg. For a 150-pound person, that works out to roughly 30 grams per meal, four times a day. Spacing your intake this way gives your muscles repeated building signals throughout the day rather than one large spike.
Protein Needs After 65
Older adults need more protein per meal to trigger the same muscle-building response that younger people get from a smaller dose. This matters because age-related muscle loss (sarcopenia) accelerates after 65 and contributes to falls, fractures, and loss of independence. Protein intake above the standard RDA has been shown to improve muscle health and help prevent sarcopenia in this population.
Most experts in aging nutrition recommend older adults aim for at least 1.0 to 1.2 g/kg per day, with some suggesting even higher amounts for those who are physically active or recovering from illness. At meals, shooting for 25 to 40 grams of protein helps overcome the blunted muscle-building response that comes with aging.
During Pregnancy and Breastfeeding
Protein needs rise during pregnancy to support fetal growth, placental development, and expanded blood volume. The recommended intake is about 60 grams per day, up from 46 grams for non-pregnant women. During breastfeeding, needs climb even further, with an additional 25 grams per day on top of the non-pregnant baseline. That puts lactating women at roughly 71 grams daily as a minimum target.
During Weight Loss
When you eat fewer calories than you burn, your body doesn’t just pull from fat stores. It also breaks down muscle. Eating more protein is the most effective dietary strategy to limit that loss. Research on older adults with obesity found that those consuming 1.1 g/kg per day preserved more muscle during weight loss than those eating the standard 0.8 g/kg.
General guidance for people losing weight is to eat 1.0 to 1.2 g/kg if you’re sedentary during your diet, and above 1.2 g/kg (roughly 1.5 times the RDA) if you’re also doing resistance training. Combining higher protein with strength exercise is consistently the most effective pairing for holding onto muscle while dropping fat. One additional detail: distributing at least 30 grams per meal (rather than eating most of your protein at dinner) improved physical function in older adults during weight loss.
Plant Protein vs. Animal Protein
Plant proteins tend to contain less of the amino acid leucine, which is the primary driver of the muscle-building signal after a meal. Soy protein produces a measurable anabolic response but is less potent than whey. Pea protein provides leucine above the minimum requirement and shows promise, particularly for older adults trying to maintain muscle.
The practical takeaway: if you eat mostly plant-based protein, you may want to aim toward the higher end of the recommended ranges to compensate for lower digestibility and amino acid differences. Combining different plant sources (legumes with grains, for example) helps fill amino acid gaps. Research also shows that adding free leucine to plant proteins like pea and soy can make them stimulate muscle building at levels comparable to whey.
Is High Protein Safe for Your Kidneys?
This is one of the most persistent concerns about eating more protein, and for healthy people, the evidence is reassuring. Randomized trials lasting six months or longer have generally shown little to no adverse effect on kidney function from high-protein diets. Data from the Nurses’ Health Study found that high protein intake was not associated with declining kidney filtration rates in people with normal kidney function.
The caveat is for people who already have kidney disease. In that case, high protein intake can accelerate damage, and intake should be managed carefully. But if your kidneys are healthy, eating 1.2 to 2.0 g/kg per day is well within the range that current evidence supports as safe.
Quick Reference by Body Weight
- 130 lbs (59 kg): minimum 47 g/day; active range 83–118 g/day
- 150 lbs (68 kg): minimum 54 g/day; active range 95–136 g/day
- 180 lbs (82 kg): minimum 65 g/day; active range 115–164 g/day
- 200 lbs (91 kg): minimum 73 g/day; active range 127–182 g/day
The “active range” uses the 1.4 to 2.0 g/kg guideline for people who exercise. If you’re sedentary and not losing weight, somewhere between 0.8 and 1.2 g/kg is a reasonable daily target. If you’re over 65 or cutting calories, lean toward 1.2 g/kg or above.