Most people looking to build muscle need between 1.4 and 2.0 grams of protein per kilogram of body weight each day. For a 180-pound (82 kg) person, that works out to roughly 115 to 164 grams of protein daily. Hit that range consistently while resistance training, and you’re covering the most important nutritional variable for muscle growth.
But the total number only tells part of the story. How you spread that protein across the day, what happens when you’re cutting weight, and how your needs shift as you age all matter. Here’s what the evidence actually supports.
Your Daily Protein Target
The International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg/day for most people doing regular resistance training. That’s about 0.6 to 0.9 grams per pound of body weight. If you weigh 150 pounds, aim for 90 to 136 grams. At 200 pounds, you’re looking at 120 to 180 grams.
Where you land within that range depends on your training intensity, how long you’ve been lifting, and your overall calorie intake. Beginners can often build muscle toward the lower end. More experienced lifters, or those eating fewer calories, benefit from pushing toward the higher end. Going above 2.0 g/kg is unlikely to add extra muscle-building benefit for most people, though it won’t cause harm either.
How to Spread Protein Across the Day
Your body doesn’t just bank unlimited protein from one massive meal. To get the most out of your daily intake, aim for at least four protein-rich meals spaced roughly three to four hours apart. Each meal should contain about 0.4 g/kg of your body weight in protein. For a 180-pound person, that’s around 30 to 35 grams per meal.
If you’re eating at the higher end of the daily range (closer to 2.2 g/kg), that works out to about 0.55 g/kg per meal, or around 45 grams per sitting for the same 180-pound person. The reason this matters comes down to what happens at the cellular level: each serving of protein needs to deliver enough of a specific amino acid called leucine (roughly 3 to 4 grams per meal) to flip the switch on muscle protein synthesis. That threshold is typically met with 25 to 40 grams of high-quality protein.
A practical pattern looks like this: breakfast, lunch, an afternoon meal or snack, and dinner, each with a solid protein source. If you train in the evening, a pre-sleep serving of 30 to 40 grams of slow-digesting protein (like cottage cheese or casein) has been shown to increase overnight muscle protein synthesis without affecting fat metabolism.
Protein Needs When Cutting Weight
If you’re eating in a calorie deficit to lose fat, your protein needs actually go up, not down. During a cut, your body is more likely to break down muscle tissue for energy, and higher protein intake acts as a buffer against that loss.
For resistance-trained individuals in a caloric deficit, the evidence supports intakes of 2.3 to 3.1 g/kg/day to maximize lean mass retention. That’s a significant jump from the standard recommendation. A 180-pound lifter cutting weight might need 190 to 255 grams of protein per day. This is one of the few situations where going well above 2.0 g/kg has a clear, practical benefit.
For people with obesity undergoing weight loss, the target is more moderate but still above baseline: at least 1.2 to 1.5 grams per kilogram combined with regular resistance training. The priority here is preserving muscle while the scale moves down.
How Protein Needs Change After 60
Older adults face a biological challenge called anabolic resistance. As you age, your muscles become less responsive to protein. The amino acids from a meal are less efficiently delivered to muscle tissue, the signaling pathways that trigger muscle repair become sluggish, and your digestive system extracts fewer usable building blocks from the same food.
The practical result: a 25-year-old can maximize muscle protein synthesis after a workout with about 20 grams of protein, while someone over 60 often needs 40 grams to get the same response. Older adults also require a higher proportion of leucine-rich protein at each meal to overcome that blunted signaling.
For healthy older adults doing resistance training, the baseline recommendation is 1.0 to 1.2 g/kg/day just for maintenance. Those recovering from illness or actively trying to build muscle should aim for 1.2 to 1.5 g/kg/day or higher. Prioritizing protein-rich meals with at least 30 to 40 grams each becomes especially important in this population.
Plant Protein vs. Animal Protein
A common concern is whether plant-based protein can build muscle as effectively as whey or other animal sources. The short answer: yes, when the amino acid profile is matched. A study comparing a pea-based protein blend (formulated to match whey’s essential amino acid content) against whey protein found no difference in body composition, strength, or power in trained athletes. Whey does not appear to have unique muscle-building properties beyond its amino acid content.
The catch is that many individual plant proteins are lower in one or more essential amino acids, particularly leucine. You can compensate by eating slightly more total protein, combining complementary sources (grains with legumes, for example), or choosing protein supplements specifically blended to match the amino acid profile of animal sources. If your total daily protein exceeds 1.6 g/kg and your meals include a variety of protein sources, the type of protein becomes a minor factor.
Is High Protein Intake Safe?
The concern you’ll hear most often is about kidney damage. Here’s what the data shows: high protein intake does cause your kidneys to filter blood at a faster rate, a response called hyperfiltration. In people with existing kidney disease or risk factors for it, this added workload can accelerate damage over time.
For people with healthy kidneys, the picture is different. Randomized trials lasting six months or longer have generally shown no meaningful decline in kidney function from high-protein diets, and no increase in protein leaking into urine. A trial comparing 2.2 g/kg to 1.1 g/kg found no adverse effects on kidney function, liver function, or bone density. The consensus for healthy individuals: there is limited evidence that high-protein diets pose a danger.
That said, if you have a family history of kidney disease, diabetes, or high blood pressure, those are risk factors worth discussing with a doctor before pushing protein intake above 2.0 g/kg for extended periods.
Putting It All Together
For most lifters, the formula is straightforward. Eat 1.4 to 2.0 g/kg of protein daily, spread across at least four meals of 25 to 40 grams each, spaced three to four hours apart. If you’re cutting, push to 2.3 to 3.1 g/kg. If you’re over 60, aim for the higher end of the range and prioritize leucine-rich foods at every meal. If you eat plant-based, match the amino acid profile through variety or blended supplements and keep total intake above 1.6 g/kg.
Consistency matters more than precision. Hitting your daily target reliably, week after week, will do more for muscle growth than obsessing over exact gram counts at any single meal.