To build muscle, you need roughly 0.7 to 1 gram of protein per pound of body weight per day. The sweet spot for most people doing resistance training falls around 0.73 grams per pound (1.6 g/kg), with diminishing returns beyond that point. If you want a simple, safe ceiling, 1 gram per pound (2.2 g/kg) covers virtually everyone.
Where the Numbers Come From
A large meta-analysis published in the British Journal of Sports Medicine pooled data from 49 studies and 1,863 participants. The researchers found that muscle gains from resistance training plateaued at 0.73 grams of protein per pound of body weight per day. Eating more protein beyond that threshold didn’t produce additional muscle growth on average.
But averages hide individual variation. The 95% confidence interval in that same analysis stretched from 0.47 to 1.0 gram per pound. That means some people in the studies did continue benefiting from higher intakes. To account for that variation, the researchers suggested that aiming for roughly 1 gram per pound per day is a reasonable upper target for anyone trying to maximize muscle growth. The International Society of Sports Nutrition’s position is broadly consistent, recommending 0.64 to 0.91 grams per pound for most exercising adults.
A Practical Range for Different Goals
Your ideal intake depends on what you’re doing with your training and your diet:
- Building muscle in a calorie surplus: 0.7 to 1.0 g per pound of body weight. Most people will capture the full benefit somewhere in this range.
- Losing fat while preserving muscle: 0.73 to 1.1 g per pound. When you’re eating fewer calories than you burn, your body is more likely to break down muscle for energy. Higher protein intakes help protect against that. The more aggressive your calorie deficit, the closer to the upper end you should aim.
- General fitness and maintenance: 0.5 to 0.7 g per pound is typically sufficient if you’re not pushing hard for size gains.
Total Weight vs. Lean Body Mass
If you’re relatively lean (under about 20% body fat for men, under about 30% for women), calculating protein based on your total body weight works fine. But if you carry a significant amount of extra body fat, using total weight can overshoot your needs. Fat tissue doesn’t require the same protein supply that muscle does.
A more accurate approach for people at higher body fat percentages is to base the calculation on lean body mass, which is your total weight minus your fat mass. For example, someone who weighs 200 pounds at 35% body fat has about 130 pounds of lean mass. Targeting 1 gram per pound of lean mass (130 grams) makes more sense than eating 200 grams. If you don’t know your body fat percentage, using your goal weight as a rough proxy works reasonably well.
How to Spread It Across the Day
Your body can use more than 20 grams of protein in a sitting, but there’s a practical ceiling on how much stimulates muscle repair at one time. Research points to 0.4 to 0.55 grams per kilogram per meal, spread across four meals, as a solid strategy. For a 180-pound person, that works out to roughly 30 to 45 grams of protein per meal.
Spacing meals every three to four hours gives your muscles repeated signals to build throughout the day. This matters more than obsessing over the post-workout “anabolic window.” The old idea that you need to slam a protein shake within 30 minutes of your last set has been largely debunked. The window for your body to use that protein extends to five or six hours around your training session. If you ate a meal containing protein an hour or two before training, you don’t need to rush to eat again the moment you finish.
One timing strategy that does have support: eating 30 to 40 grams of a slow-digesting protein (like casein, found in cottage cheese or casein powder) before bed. This increases muscle protein synthesis overnight without disrupting fat burning.
Why Older Adults Need More
As you age, your muscles become less responsive to the protein you eat. This phenomenon, called anabolic resistance, means older adults need a bigger dose of protein to trigger the same muscle-building response that a smaller dose would produce in a 25-year-old. Research estimates the per-meal dose required is about 68% higher in older adults, translating to roughly 40 grams of protein per meal instead of the 20 to 25 grams that works well for younger people.
For total daily intake, expert panels recommend at least 0.45 to 0.68 grams per pound for older adults who want to maintain muscle. Those who are actively strength training to build muscle should aim for the same 0.73 to 1.0 gram per pound range as younger lifters, possibly at the higher end to compensate for that blunted response.
Does Going Higher Than 1 Gram Help?
Some research has looked at intakes above 1.4 grams per pound (over 3.0 g/kg). At those levels, the extra protein doesn’t appear to build additional muscle, but there’s preliminary evidence it may help with fat loss in experienced lifters. The mechanism isn’t entirely clear, and the effect is modest. For most people, pushing that high means spending more on food, feeling uncomfortably full, and crowding out carbohydrates and fats that also support training performance. There’s no safety concern for healthy kidneys at these intakes, but the practical return on investment drops off sharply past 1 gram per pound.
Protein Quality Matters Too
Not all protein sources stimulate muscle growth equally. The key driver is leucine, an amino acid that acts as the “on switch” for muscle protein synthesis. You need roughly 700 to 3,000 milligrams of leucine per meal to flip that switch effectively. Animal proteins like chicken, eggs, dairy, and fish are naturally high in leucine and contain the full spectrum of essential amino acids your muscles need. Plant proteins can absolutely work, but you typically need a larger serving or a combination of sources (like rice and beans, or soy-based foods) to hit the same leucine threshold. If you’re plant-based, aiming toward the higher end of the protein range helps compensate for the lower leucine density per gram.
The Bottom Line in Practice
For a 170-pound person aiming to build muscle: eat between 120 and 170 grams of protein per day, split across three to four meals of 30 to 45 grams each. Prioritize protein sources rich in essential amino acids. If you’re cutting calories, push toward the higher end. If you’re over 50, also push toward the higher end. And if the math feels overwhelming, just remember that 0.8 grams per pound covers the vast majority of people and leaves very little muscle growth on the table.