Most healthy adults should get 10% to 35% of their daily calories from protein. That range, known as the Acceptable Macronutrient Distribution Range, covers everyone from sedentary office workers to serious athletes. Where you land within it depends on your activity level, age, body composition goals, and whether you’re pregnant or breastfeeding. For a person eating 2,000 calories a day, 10% to 35% translates to roughly 50 to 175 grams of protein.
The Baseline for Most Adults
The standard recommendation for healthy adults is 0.8 grams of protein per kilogram of body weight per day. For a 150-pound person, that works out to about 55 grams. The World Health Organization puts this slightly differently: 10% to 15% of total daily calories from protein is generally enough for adults, which lands around 50 to 75 grams on a 2,000-calorie diet.
That baseline keeps you from becoming deficient, but many nutrition researchers consider it a floor rather than a target. The 0.8 g/kg figure was designed to prevent deficiency in most people, not to optimize muscle retention, recovery, or body composition. If you’re relatively inactive and at a healthy weight, staying in the 10% to 15% range will meet your needs. But if you exercise regularly, are trying to lose fat, or are over 65, you’ll likely benefit from eating more.
How Activity Level Changes the Number
If you exercise regularly, 0.8 g/kg is not enough. The International Society of Sports Nutrition recommends 1.4 to 2.0 grams per kilogram of body weight per day for most people who train, whether that’s running, cycling, lifting, or playing recreational sports. For a 170-pound person, that’s roughly 108 to 154 grams of protein daily, or about 22% to 31% of a 2,000-calorie diet.
The upper end of that range matters most during two scenarios: when you’re trying to build muscle and when you’re cutting calories to lose fat. If you’re dieting while resistance training, protein needs can climb even higher, to 2.3 to 3.1 g/kg per day, to help preserve lean mass while you lose weight. That’s a lot of protein, and it pushes you toward the top of the 35% ceiling or even slightly beyond it.
Protein Needs After 65
Older adults lose muscle more easily and build it less efficiently. The process of age-related muscle loss (sarcopenia) accelerates after 65, and the standard 0.8 g/kg recommendation doesn’t appear to be enough to slow it down. Research on muscle protein synthesis in older adults suggests aiming for 25 to 30 grams of high-quality protein at each meal, rather than clustering most protein at dinner, which is the typical eating pattern in Western diets.
Spreading protein across three meals at 25 to 30 grams each gives you 75 to 90 grams a day, which for most older adults falls in the 15% to 25% range of total calories. That’s meaningfully higher than the standard guideline, but it’s the amount research suggests is needed to maximally stimulate muscle repair and maintenance at each eating occasion.
Protein for Weight Loss
Protein is the most satiating macronutrient. Studies comparing meals at different protein levels consistently find that higher-protein meals (25% to 30% of calories) leave people feeling fuller for longer than meals with only 10% to 15% protein. In one study, a meal with 60% of its calories from protein produced significantly greater fullness than a meal at 19%.
For practical weight loss purposes, you don’t need to eat 60% protein. A diet providing 20% to 30% of calories from protein is considered “high protein” relative to a standard diet at 10% to 15%. The interesting thing is that the absolute grams of protein often don’t differ dramatically between a normal-calorie diet and a reduced-calorie diet. When you cut total calories, protein naturally occupies a bigger percentage of the pie even if the gram amount stays the same. So if you’re eating 1,500 calories instead of 2,000, and you keep protein at 100 grams, that protein jumps from 20% to 27% of your diet without you eating any more of it.
Pregnancy and Breastfeeding
Protein needs increase during pregnancy and rise further during breastfeeding. The current official recommendation for lactating women is about 1.05 g/kg per day, but newer research using more precise measurement methods suggests the real requirement is closer to 1.7 to 1.9 g/kg per day for women exclusively breastfeeding in the first six months. That’s roughly double the standard adult recommendation. Late pregnancy (around 36 weeks) appears to require about 1.5 g/kg per day.
For a 140-pound breastfeeding woman, the updated estimates translate to roughly 108 to 121 grams of protein daily. On a 2,200-calorie diet (a common target for breastfeeding), that’s about 20% to 22% of total calories.
How Much Is Too Much
Long-term intake of up to 2 grams per kilogram of body weight per day is considered safe for healthy adults. The tolerable upper limit, for people whose bodies have adapted to high protein intake over time, is around 3.5 g/kg per day. Chronically exceeding 2 g/kg without a specific reason (like competitive bodybuilding with guided nutrition) can increase the risk of digestive issues and may stress the kidneys and cardiovascular system over time.
For most people, staying within the 10% to 35% range keeps protein intake in a safe zone. Even at the high end, a person eating 2,500 calories a day at 35% protein would consume about 219 grams, which for someone weighing 180 pounds (82 kg) comes out to 2.7 g/kg. That’s high but within the tolerable range for an adapted individual.
A Simple Way to Find Your Number
Rather than obsessing over exact percentages, pick the category that fits you and work from grams per kilogram of body weight. Divide your weight in pounds by 2.2 to get kilograms, then multiply by the appropriate factor:
- Sedentary adult: 0.8 g/kg (about 10% to 15% of calories)
- Recreationally active: 1.2 to 1.4 g/kg (about 15% to 20%)
- Regular strength or endurance training: 1.4 to 2.0 g/kg (about 20% to 30%)
- Dieting while training: 2.0 to 2.4 g/kg (about 25% to 35%)
- Adults over 65: aim for 25 to 30 g per meal, three times daily
- Pregnant (third trimester): ~1.5 g/kg
- Breastfeeding: ~1.7 to 1.9 g/kg
A 160-pound person who exercises a few times a week, for example, weighs about 73 kg. At 1.4 g/kg, that’s roughly 102 grams of protein per day. On a 2,000-calorie diet, that’s about 20% of total calories, comfortably within the recommended range and enough to support muscle repair and recovery.