To gain muscle, most people need 1.6 to 2.2 grams of protein per kilogram of body weight per day. For a 180-pound (82 kg) person, that works out to roughly 130 to 180 grams of protein daily. Hitting that range, combined with resistance training, is the single most important nutritional factor for building muscle.
How to Calculate Your Target
The math is straightforward: divide your body weight in pounds by 2.2 to get your weight in kilograms, then multiply by 1.6 and 2.2 to find your range. Here’s what that looks like at common body weights:
- 140 lbs (64 kg): 102–141 g protein per day
- 160 lbs (73 kg): 117–161 g per day
- 180 lbs (82 kg): 131–180 g per day
- 200 lbs (91 kg): 146–200 g per day
- 220 lbs (100 kg): 160–220 g per day
The International Society of Sports Nutrition sets the floor slightly lower, at 1.4 g/kg/day, for maintaining muscle in active people. But if your goal is to maximize growth, aiming for the 1.6 to 2.0 range is the well-supported sweet spot. Going above 2.2 g/kg doesn’t appear to build additional muscle, though intakes above 3.0 g/kg have shown some benefit for losing body fat in experienced lifters.
How You Spread It Out Matters
Eating 150 grams of protein in one or two large meals is less effective than distributing it across three or four meals. Research consistently shows that spreading protein evenly throughout the day stimulates more muscle building over a 24-hour period than loading most of it into dinner, which is how many people eat by default.
The target per meal is 30 to 45 grams of protein. A study comparing even distribution (about 30 grams at each meal) against a skewed pattern (10 grams at breakfast, 15 at lunch, 65 at dinner) found that even distribution produced significantly more muscle protein synthesis, despite total daily intake being identical. Spacing those meals every three to four hours gives your body repeated signals to build new muscle tissue throughout the day.
As a practical rule: aim for at least three protein-rich meals, each containing 30 or more grams. If you eat four or five smaller meals, 20 to 40 grams per sitting works well. The key is avoiding the common pattern of a low-protein breakfast, a moderate lunch, and one massive protein serving at night.
Protein Timing Is Overrated
The idea of a narrow “anabolic window” after your workout, where you need to chug a protein shake within 30 minutes or lose your gains, doesn’t hold up. Two separate meta-analyses found no benefit to consuming protein at a specific time relative to exercise when total daily intake was adequate. A 2024 study in Frontiers in Nutrition confirmed this directly: resistance-trained men who consumed protein at different times of day saw identical improvements in muscle mass and performance, as long as their daily totals matched.
If anything, the anabolic window appears to extend over several hours, not the 30-minute slot that gym culture has promoted for decades. Total daily protein intake is the primary driver of muscle growth. That said, having a protein-rich meal within a couple of hours before or after training is still a reasonable habit, especially since it helps you hit your daily target anyway.
When You’re Cutting Body Fat
If you’re trying to lose fat while preserving muscle, your protein needs go up, not down. During a caloric deficit, the recommended range increases to 1.6 to 2.4 g/kg per day. The higher end of that range becomes more important the more aggressive your calorie cut is.
This is one of the most common mistakes people make during a diet. Reducing calories often means reducing protein along with everything else, which accelerates muscle loss. Keeping protein high while dropping carbs and fats is the most effective strategy for maintaining the muscle you’ve already built.
Adjustments for Adults Over 50
Older adults face a biological challenge called anabolic resistance: aging muscles don’t respond to protein as efficiently as younger ones do. A 22-year-old might only need about 0.2 g/kg per meal to trigger muscle building, while a 70-year-old needs roughly 0.4 g/kg per meal to get the same response. That translates to about 30 to 35 grams per meal for most older adults.
For a 165-pound person over 50, that means each of three daily meals should contain around 30 grams of protein. This is a higher per-meal threshold than younger adults require, so older individuals benefit especially from planning protein into every meal rather than relying on a single large serving.
Plant Protein Requires Higher Amounts
Not all protein sources are equally efficient at building muscle. Animal proteins (meat, fish, eggs, dairy) have higher digestibility, more essential amino acids, and more leucine, the specific amino acid that triggers muscle protein synthesis. The leucine threshold for maximally stimulating muscle growth is about 2 to 3 grams per meal, and animal proteins reach that threshold more easily.
If you eat a plant-based diet, you can absolutely build muscle, but you’ll likely need to eat more total protein to compensate. Young adults on plant-based diets should aim for at least 20% more protein per meal than omnivores. For older plant-based eaters, that adjustment rises to 30% or more. In practical terms, that means targeting at least 30 grams per meal if you’re young and at least 40 grams if you’re over 50.
Soy protein is the standout plant source, with a quality score above 0.9 on the standard digestibility scale, comparable to animal proteins. Nearly all other plant proteins score below 0.9. Combining complementary sources (rice and beans, for instance) helps fill in amino acid gaps. Plant-based protein isolates, particularly soy isolate, can also close the gap with animal sources.
One additional challenge: plant foods are less protein-dense, meaning you’ll often need to eat a larger volume of food and more total calories to hit the same protein targets. This is worth planning for if you’re also trying to manage your calorie intake.
Is High Protein Safe for Your Kidneys?
For people with healthy kidneys, high protein intake does not appear to cause kidney damage. A meta-analysis published in Frontiers in Nutrition found that higher intakes of total protein actually lowered the risk of chronic kidney disease by 18%. Plant protein showed an even larger protective effect, reducing risk by 23%.
High protein diets do increase the kidneys’ filtration rate, which is a normal adaptive response, not a sign of harm. The concern about protein and kidney damage applies specifically to people who already have kidney disease, where protein restriction (around 0.8 g/kg/day) is a standard recommendation. If your kidneys are healthy, eating in the 1.6 to 2.2 g/kg range for muscle building is well within safe bounds.
Putting It Into Practice
The simplest approach is to work backward from your daily target. If you weigh 180 pounds and aim for 1.8 g/kg, your goal is about 150 grams per day. Split across four meals, that’s roughly 37 grams each. A chicken breast has about 30 grams, a cup of Greek yogurt has 15 to 20, three eggs have about 18, and a scoop of whey protein powder has 20 to 25.
A pre-sleep protein serving of 30 to 40 grams, particularly from a slower-digesting source like casein (found in cottage cheese or casein powder), has been shown to increase overnight muscle protein synthesis and boost metabolic rate. This is one of the easier habits to add if you’re falling short of your daily target.
Consistency matters more than precision. Hitting your range on most days, spread across multiple meals, with enough leucine-rich protein at each sitting, covers the vast majority of what nutrition can do for muscle growth. Everything else is minor optimization.