For most people, the ideal protein intake falls between 0.5 and 1 gram per pound of body weight per day, depending on your activity level and goals. A sedentary adult can get by on as little as 0.36 grams per pound, which is the current minimum recommendation. But if you exercise regularly, want to build muscle, or are trying to lose fat without losing muscle, you’ll need significantly more.
The Baseline: Minimum vs. Optimal
The official Recommended Dietary Allowance for protein is 0.36 grams per pound of body weight per day (0.8 g/kg). For a 180-pound person, that works out to about 65 grams. This number was established using short-term nitrogen balance studies and represents the minimum needed to prevent deficiency in a healthy, mostly sedentary adult. It is not a target for anyone trying to optimize their body composition, performance, or long-term health.
Think of the RDA as the floor, not the ceiling. Most nutrition professionals now recommend that active people aim for roughly double that amount, and even sedentary individuals may benefit from eating above the minimum, particularly as they age.
Protein for Building Muscle
If you’re strength training and want to add muscle, the well-supported range is 0.64 to 0.91 grams per pound per day (1.4 to 2.0 g/kg). This range comes from joint recommendations by the Academy of Nutrition and Dietetics, Dietitians of Canada, the American College of Sports Medicine, and the International Society of Sports Nutrition. For a 180-pound person, that translates to roughly 115 to 164 grams of protein daily.
Within that range, the strongest evidence points to about 0.73 grams per pound (1.6 g/kg) as the sweet spot where most people see the best muscle-building results from resistance training. Going higher doesn’t hurt, but the additional benefit tapers off. A 150-pound person, for example, would aim for around 110 grams per day. A 200-pound person would target about 145 grams.
Protein for Fat Loss
When you’re eating in a calorie deficit, protein becomes even more important. Cutting calories signals your body to break down both fat and muscle for energy. Higher protein intake shifts that balance, helping you hold onto muscle while losing more fat.
A study comparing two groups of young men on an aggressive 40% calorie deficit illustrates this clearly. The group eating about 0.55 grams per pound (1.2 g/kg) barely maintained their muscle mass, gaining just 0.1 kg of lean tissue over four weeks. The group eating double that, around 1.1 grams per pound (2.4 g/kg), actually gained 1.2 kg of lean mass and lost more fat (10.6 pounds vs. 7.7 pounds) despite eating the same number of total calories. Both groups did intense resistance and anaerobic exercise.
The International Society of Sports Nutrition suggests that resistance-trained individuals cutting calories may need as much as 1.0 to 1.4 grams per pound (2.3 to 3.1 g/kg) to maximize muscle retention. The more aggressive your calorie deficit and the leaner you already are, the more protein you need to protect against muscle loss.
Protein Needs After 50
Aging muscles become less responsive to protein. A dose that easily triggers muscle repair in a 25-year-old may barely register in a 65-year-old. Research shows that older adults need a higher threshold of essential amino acids per meal, around 10 to 15 grams, to stimulate the same muscle-building response that younger adults get from smaller amounts.
In practical terms, this means adults over 50 should aim for 25 to 30 grams of high-quality protein at each meal rather than loading most of their protein into dinner. The standard RDA of 0.36 grams per pound gives a 75 kg (165-pound) person only about 20 grams per meal spread across three meals, which falls short of the threshold needed to effectively maintain muscle. Bumping intake to at least 0.5 to 0.7 grams per pound helps counteract the gradual muscle loss that accelerates with age.
How to Spread Protein Across the Day
Your body can use more protein in a single sitting than the old “30 grams per meal” myth suggests, but distribution still matters. The current evidence-based recommendation is to eat about 0.18 grams per pound per meal (0.4 g/kg) across at least four meals to maximize muscle protein synthesis throughout the day. For a 170-pound person, that’s roughly 30 to 35 grams per meal.
If you’re aiming for the higher end of the intake range, spreading up to 0.25 grams per pound per meal (0.55 g/kg) across four meals lets you reach about 1 gram per pound per day without wasting any of it. For older adults, each meal may need to be closer to 35 to 40 grams to clear the higher stimulation threshold.
A pre-sleep protein serving of 30 to 40 grams, particularly from a slow-digesting source like casein (found in cottage cheese and casein protein powder), has been shown to increase overnight muscle protein synthesis and slightly boost metabolic rate.
Quick Reference by Goal
- Sedentary adult (minimum): 0.36 g per pound (e.g., 65 g for a 180 lb person)
- Generally active or health-focused: 0.5 to 0.7 g per pound (e.g., 90–125 g for 180 lb)
- Building muscle: 0.7 to 1.0 g per pound (e.g., 125–180 g for 180 lb)
- Losing fat while preserving muscle: 1.0 to 1.4 g per pound (e.g., 180–250 g for 180 lb)
- Adults over 50: 0.5 to 0.7 g per pound minimum, with 25–30 g per meal
Is There an Upper Limit?
For healthy adults with normal kidney function, protein intakes up to 1.4 grams per pound (3.1 g/kg) have been studied without adverse effects on kidney health or other markers. Some research has even explored intakes above 1.36 grams per pound (3.0 g/kg) in resistance-trained individuals and found positive effects on body composition, specifically greater fat loss, with no reported harm.
That said, eating extremely high protein means something else in your diet gets crowded out. If protein displaces fruits, vegetables, and healthy fats, you may miss out on fiber, vitamins, and other nutrients. For most people, staying in the 0.7 to 1.0 grams per pound range covers the vast majority of the benefit without requiring heroic meal planning. If you have existing kidney disease, your situation is different, and protein recommendations should come from your care team.