The baseline recommendation for protein is 0.8 grams per kilogram of body weight per day, or about 0.36 grams per pound. For a 150-pound person, that works out to roughly 54 grams daily. But that number is a minimum to prevent deficiency in sedentary adults, not a target for optimal health. Depending on your age, activity level, and goals, you likely need more.
The Baseline: 0.8 Grams Per Kilogram
The Recommended Dietary Allowance of 0.8 g/kg/day was set to cover the basic needs of most healthy, sedentary adults. It keeps you from losing muscle under normal conditions, but it wasn’t designed with fitness, aging, or weight loss in mind. If you don’t exercise regularly and you’re under 65, this number is adequate. For most other people, it’s a floor, not a ceiling.
To calculate your baseline: divide your weight in pounds by 2.2 to get kilograms, then multiply by 0.8. A 180-pound person (about 82 kg) would need at least 65 grams of protein per day at this level.
Building Muscle: 1.6 to 2.0 Grams Per Kilogram
If you’re doing resistance training and want to build or maintain muscle, you need significantly more protein than the baseline. Research on trained men found that whole-body muscle building maxes out at roughly 2.0 g/kg/day. Beyond that point, additional protein didn’t produce further gains. The 95% confidence interval in that study ranged from about 1.6 to 2.4 g/kg/day, which means most people doing regular strength training will see full benefits somewhere in the 1.6 to 2.0 range.
For a 170-pound lifter (77 kg), that translates to 123 to 154 grams of protein per day. If you’re newer to training, the lower end of that range is likely sufficient. More experienced lifters with higher muscle mass tend to benefit from pushing closer to 2.0 g/kg.
Losing Weight Without Losing Muscle
When you’re eating fewer calories than you burn, your body doesn’t just pull energy from fat. It also breaks down muscle tissue. Protein is your main tool for limiting that loss. Current recommendations for athletes cutting weight land between 1.6 and 2.4 g/kg/day, with some research suggesting resistance-trained individuals benefit from intakes as high as 2.7 g/kg during a calorie deficit.
That said, going above about 2.4 g/kg/day during a diet doesn’t appear to provide much additional muscle-sparing benefit. The practical takeaway: if you’re dieting and want to hold onto muscle, aim for at least 1.6 g/kg and ideally closer to 2.0 or above, especially if you’re also lifting weights. Pair that protein with resistance training, because protein alone won’t preserve muscle without a stimulus to maintain it.
Adults Over 65: Higher Needs Than You’d Expect
Aging muscles become less efficient at using dietary protein. The PROT-AGE study group, an international panel focused on nutrition in older adults, recommends 1.0 to 1.2 g/kg/day as a minimum for people over 65. That’s 25 to 50% more than the standard RDA.
Older adults who exercise regularly should aim for at least 1.2 g/kg/day. Those managing acute or chronic illness may need 1.2 to 1.5 g/kg/day to prevent the progressive muscle loss known as sarcopenia, which contributes to falls, fractures, and loss of independence. The one notable exception: people with advanced kidney disease (specifically those with significantly reduced kidney filtration who aren’t on dialysis) may need to limit protein intake rather than increase it.
Pregnancy and Breastfeeding
Before conception, the standard 0.8 g/kg/day applies, with a minimum of 40 grams daily regardless of body weight. During pregnancy, protein needs rise to at least 60 grams per day, which should make up roughly 20 to 25 percent of total calories. For many women, especially those with higher body weights or carrying multiples, actual needs may exceed that 60-gram floor.
How You Spread It Out Matters
Your body can only use so much protein for muscle building at one time. Research consistently points to about 20 to 25 grams of high-quality protein per meal as the amount that maximally stimulates muscle repair in younger adults. Older adults may need a bit more per sitting because their muscles require a stronger signal to kick-start that process. Studies suggest older adults benefit from reaching about 3 grams of leucine per meal, which is the specific amino acid that triggers muscle building. That typically means 30 to 40 grams of protein per meal from a quality source.
Rather than loading all your protein into one or two meals, spreading it across three or four eating occasions gives your muscles repeated opportunities to rebuild throughout the day. A common mistake is eating a low-protein breakfast (toast, cereal, fruit) and cramming most protein into dinner.
Plant vs. Animal Protein Sources
Not all protein is absorbed equally. Animal proteins (meat, fish, eggs, dairy) deliver a complete set of essential amino acids and are more easily digested than most plant proteins. Plant sources like beans, lentils, nuts, and grains are lower in one or more essential amino acids and are generally less digestible because of fiber and other compounds that slow breakdown in the gut.
This doesn’t mean plant-based diets can’t meet your protein needs. It does mean you may need to eat a bit more total protein to compensate for lower absorption, and you’ll want to combine different plant sources throughout the day so the amino acid profiles complement each other. Soy and quinoa are among the few plant proteins that contain all essential amino acids in meaningful amounts.
Quick Reference by Goal
- Sedentary adult under 65: 0.8 g/kg/day (minimum)
- Recreationally active adult: 1.0 to 1.4 g/kg/day
- Strength training for muscle growth: 1.6 to 2.0 g/kg/day
- Dieting while preserving muscle: 1.6 to 2.4 g/kg/day
- Adults over 65: 1.0 to 1.2 g/kg/day (1.2 to 1.5 if ill or very active)
- Pregnant women: minimum 60 g/day (roughly 20 to 25% of calories)
Is Too Much Protein Dangerous?
For people with healthy kidneys, there’s no strong evidence that high protein intake causes kidney damage. The concern about protein harming kidneys comes from studies on people who already have chronic kidney disease, where high intake can accelerate decline. For those individuals, guidelines recommend limiting protein to as low as 0.55 to 0.8 g/kg/day depending on disease severity.
Interestingly, one large study of people with existing kidney disease found that intakes above 0.8 g/kg/day were actually associated with about an 8% lower mortality risk for every additional 0.2 g/kg/day consumed, complicating the traditional advice to restrict protein in all kidney patients. The picture is nuanced, but if your kidneys are functioning normally, protein intakes in the 1.6 to 2.4 g/kg range are well within what healthy adults tolerate without issues.