To maximize muscle growth, 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 translates to roughly 130 to 180 grams daily. This range is supported by the International Society of Sports Nutrition, which sets 1.4 to 2.0 g/kg/day as sufficient for most exercising individuals, with the upper end favoring those focused specifically on hypertrophy.
The Daily Target That Matters Most
A large meta-analysis of resistance training studies found that 1.6 g/kg/day is the point where additional protein stops producing significantly more muscle growth in most younger adults. That number serves as a reliable floor. The ceiling, around 2.2 g/kg/day, accounts for individual variation in how efficiently people digest, absorb, and use dietary protein. If you’re newer to lifting, you can likely build muscle near the lower end. If you’ve been training consistently for years and are pushing harder in the gym, aiming closer to 2.0 g/kg/day or slightly above is a reasonable strategy.
For practical reference, here’s what the range looks like at common body weights:
- 150 lbs (68 kg): 109 to 150 g/day
- 180 lbs (82 kg): 131 to 180 g/day
- 200 lbs (91 kg): 146 to 200 g/day
- 220 lbs (100 kg): 160 to 220 g/day
These numbers use total body weight. If you’re carrying significant extra body fat, using your goal weight or lean body mass estimate will give you a more useful target.
How to Spread Protein Across Meals
Your body doesn’t use protein in one big lump. Each meal triggers a burst of muscle protein synthesis, and the size of that burst depends partly on how much protein you eat. Research on younger adults shows that about 0.4 g/kg per meal optimally stimulates this process. For most people, that’s somewhere between 30 and 50 grams per sitting.
Spreading your intake across at least four meals is the simplest way to hit your daily target while keeping each dose in the effective range. If your goal is 1.6 g/kg/day, four meals of 0.4 g/kg each gets you there exactly. If you’re aiming for the higher end of 2.2 g/kg/day, that works out to roughly 0.55 g/kg per meal across four sittings. Three meals can work too, but each one needs to be more protein-dense, and you may not get the same repeated stimulation of muscle building throughout the day.
Protein Timing and the “Anabolic Window”
The idea that you need to chug a protein shake within 30 minutes of your last set has been overstated for years. A thorough review of the evidence found no consistent indication of an ideal post-exercise timing scheme for maximizing muscle growth. Total daily intake matters far more than precisely when you eat relative to your workout.
That said, timing isn’t completely irrelevant. If you train fasted or haven’t eaten in three to four hours before your session, getting at least 25 grams of protein reasonably soon afterward (within an hour or two) makes sense to shift your body out of a catabolic state. But if you had a solid meal one to two hours before training, your next scheduled meal is likely sufficient. You don’t need to rush.
Higher Protein Needs During a Caloric Deficit
When you’re eating fewer calories than you burn, your body is more inclined to break down muscle for energy. Protein requirements go up to counteract this. The ISSN recommends 2.3 to 3.1 g/kg/day for resistance-trained individuals during a cut, which is substantially higher than what’s needed during a bulk or maintenance phase.
A meta-analysis of 47 studies found that protein intake above 1.3 g/kg/day significantly prevented muscle mass loss during weight loss, while intake below 1.0 g/kg/day was associated with greater muscle decline. If you’re dieting and want to hold onto your muscle, prioritizing protein is the single most protective nutritional strategy available to you. For a 180-pound person during an aggressive cut, that could mean 190 to 250 grams per day.
How Age Changes the Equation
Older adults face a biological challenge called anabolic resistance. Their muscles respond less robustly to both protein intake and resistance exercise, meaning the same meal that maximally stimulates muscle building in a 25-year-old produces a weaker response in a 60-year-old. Younger adults max out muscle protein synthesis at about 0.24 g/kg per meal, while older adults need roughly 0.40 g/kg per meal to achieve a comparable response.
For daily totals, adults over 50 who are resistance training should aim for at least 1.2 g/kg/day, with evidence supporting intakes up to 1.3 g/kg/day or higher to optimize muscle retention and physical function. The standard recommendation of 0.8 g/kg/day, designed for the general sedentary population, is increasingly recognized as insufficient for preserving muscle mass in aging adults.
Plant Protein vs. Animal Protein
Animal proteins like meat, eggs, dairy, and fish contain all essential amino acids in high concentrations and are more easily digested. Plant proteins tend to be lower in one or more essential amino acids and are generally less digestible, which reduces their muscle-building potential gram for gram.
A meta-analysis of randomized controlled trials found that animal protein produced a small but statistically significant advantage in percent lean mass compared to plant protein. In practical terms, though, the difference was modest (about half a percentage point). If you eat a primarily plant-based diet, you can close this gap by eating a higher total amount of protein and combining different plant sources to cover your full amino acid profile. Hitting at least 2 grams of leucine per meal across four daily meals is a useful benchmark; leucine is the amino acid most responsible for triggering muscle protein synthesis, and plant sources deliver less of it per gram of total protein.
Is High Protein Intake Safe for Your Kidneys?
A systematic review of 26 studies in healthy adults found that protein intakes above the standard recommended allowance had no adverse effect on kidney function. Most studies showed that higher protein intake increased the kidneys’ filtration rate, which is a normal adaptive response, not a sign of damage. Blood markers of kidney function remained within healthy ranges.
The caveat is that most of these studies lasted less than six months, so very long-term data at extremely high intakes (above 3.0 g/kg/day) is still limited. For people with pre-existing kidney disease, the situation is different and higher intakes may be harmful. But for healthy adults lifting weights and eating in the 1.6 to 2.2 g/kg/day range, kidney concerns are not supported by current evidence.