Most people looking to build muscle need between 1.4 and 2.0 grams of protein per kilogram of body weight per day. For a 180-pound (82 kg) person, that works out to roughly 115 to 164 grams daily. That range, established by the International Society of Sports Nutrition, covers the needs of most people who exercise regularly. But where you fall within it depends on your training intensity, whether you’re cutting or bulking, and your age.
The Daily Target That Actually Matters
The most widely cited research points to 1.6 g/kg/day as the minimum effective dose for maximizing muscle growth when paired with resistance training. Going above that, up to about 2.2 g/kg/day, may offer a small additional benefit for some people, but the gains taper off sharply. For practical purposes, aiming for 0.7 to 1.0 gram per pound of body weight per day puts you squarely in the optimal zone.
To put real numbers on this: a 150-pound person should target roughly 105 to 150 grams per day. A 200-pound person would aim for 140 to 200 grams. If you’re carrying significant extra body fat, basing your calculation on your goal weight or lean body mass gives a more useful number than using your total weight.
How to Spread Protein Across Meals
Your body doesn’t just look at the total protein you eat in a day. How you distribute it across meals matters too. The muscle-building response peaks at roughly 0.4 g/kg per meal, which translates to about 20 to 40 grams of protein per sitting for most adults. Eating significantly more than that in a single meal doesn’t appear to stimulate additional muscle building in the short term, though the extra protein still gets used for other bodily functions and energy.
Spreading your total intake across at least four meals, spaced about three to four hours apart, appears to be the most effective strategy. So if your daily target is 160 grams, you’d aim for roughly 40 grams at each of four meals rather than cramming 80 grams into two large meals. This keeps the muscle-building signal elevated throughout the day rather than spiking it once or twice.
Why Cutting Calories Changes the Equation
If you’re eating in a caloric deficit to lose fat, your protein needs go up, not down. When your body has less total energy available, it’s more likely to break down muscle tissue for fuel. The International Society of Sports Nutrition recommends 2.3 to 3.1 g/kg/day for resistance-trained individuals during a calorie deficit. That’s substantially higher than the standard recommendation.
For a 170-pound person cutting weight, that could mean 180 to 240 grams of protein per day. It’s a lot, but the evidence supports it: higher protein intake during a caloric deficit preserves an additional 400 to 800 grams of lean mass compared to lower intakes. That difference compounds over weeks of dieting. Eating below even the basic recommended dietary allowance of 0.8 g/kg/day while in a deficit accelerates muscle loss at a rate of roughly 0.2 to 0.5 percent per week.
When you’re eating at maintenance calories or in a surplus, going above the standard 1.4 to 2.0 g/kg range doesn’t appear to add muscle. Some evidence suggests very high intakes above 3.0 g/kg/day may help with fat loss in trained individuals, but for pure muscle building in a caloric surplus, 1.6 to 2.0 g/kg is sufficient.
Protein Needs After 50
Older adults need more protein per meal to trigger the same muscle-building response as younger people. While a 25-year-old’s muscles respond strongly to about 0.24 g/kg of protein in a single meal, someone over 50 may need closer to 0.40 g/kg to reach the same level of stimulation. That’s roughly 25 to 30 grams per meal for a younger person versus 30 to 40 grams for an older adult.
The reason comes down to something called anabolic resistance: aging muscles become less sensitive to the protein you eat. This effect appears more pronounced in older women than older men. One study found that 0.25 g/kg of protein boosted the muscle-building response by 56% in older men, but only 13% in older women. For older adults, the amino acid leucine plays a particularly important role. Consuming roughly 3 to 4 grams of leucine per meal (found naturally in about 25 to 30 grams of high-quality protein) helps overcome this blunted response.
Plant vs. Animal Protein Sources
A systematic review of randomized controlled trials found that protein source, whether plant or animal, did not significantly affect total lean mass gains or muscle strength, provided total protein intake was adequate. This held true across studies where participants consumed anywhere from 1.0 to 3.1 g/kg/day. As long as you’re hitting your daily target and eating a varied diet, the protein can come from chicken, lentils, dairy, tofu, or any combination.
There is one nuance: animal proteins tend to be higher in leucine and other essential amino acids per gram, so plant-based eaters may benefit from eating slightly more total protein or combining complementary sources throughout the day. Some earlier research suggested plant protein might require higher quantities to match animal protein’s acute muscle-building effect, but longer-term studies looking at actual muscle growth found no meaningful difference when total intake was sufficient.
Without resistance training, neither protein source nor protein quantity above the basic recommended amount produced significant changes in lean mass. The training itself is the primary driver. Protein provides the raw material, but lifting is the signal your body needs to actually use it for building muscle.
A Practical Framework
Here’s how to set your protein target based on your situation:
- Building muscle in a caloric surplus: 1.6 to 2.2 g/kg/day (0.7 to 1.0 g per pound)
- Losing fat while preserving muscle: 2.3 to 3.1 g/kg/day (1.0 to 1.4 g per pound)
- General fitness and maintenance: 1.4 to 1.6 g/kg/day (0.6 to 0.7 g per pound)
- Adults over 50: Aim for the higher end of each range, with at least 30 to 40 grams per meal
Divide your daily total across four meals spaced three to four hours apart, with each meal containing at least 20 to 40 grams of protein. Prioritize protein sources that give you a broad range of essential amino acids, whether that’s eggs, Greek yogurt, fish, beans, or a protein shake. The best protein source is the one you’ll actually eat consistently enough to hit your numbers.