To gain muscle, most people need 1.6 grams of protein per kilogram of body weight per day (about 0.73 grams per pound). For a 180-pound person, that works out to roughly 130 grams daily. This number comes from a meta-analysis of 74 randomized controlled trials involving nearly 2,700 people, which found that combining resistance training with 1.6 g/kg/day of protein maximized muscle growth. Going higher than that didn’t produce additional muscle or strength gains.
That said, the number shifts depending on your age, whether you’re in a calorie deficit, and how you spread your protein across the day. Here’s how to dial in your intake.
The Range That Actually Matters
The broad recommendation for people who lift weights regularly is 1.2 to 1.7 grams of protein per kilogram of body weight. But within that range, the evidence points to 1.6 g/kg as the ceiling for muscle-building benefits when you’re eating enough total calories. That’s not a starting point or a minimum. It’s the point of diminishing returns, where eating more protein simply stops translating into more muscle.
To calculate your target: divide your weight in pounds by 2.2 to get kilograms, then multiply by 1.6. A 200-pound person (91 kg) would aim for about 145 grams of protein per day. A 150-pound person (68 kg) would target around 109 grams.
If you carry a significant amount of body fat, these calculations can overestimate your needs, since fat tissue doesn’t require protein the way muscle does. In that case, basing your calculation on your goal weight or estimated lean mass gives a more realistic number.
Why You Need More When Cutting
The 1.6 g/kg ceiling applies when you’re eating at or above your calorie needs. If you’re in a calorie deficit, the rules change. Your body is more likely to break down muscle for energy when calories are scarce, and extra protein helps counteract that.
During a significant deficit (around 40% below maintenance calories with intense training), bumping protein up to about 2.4 g/kg per day can help you hold onto lean mass and even add a small amount while losing fat. For less aggressive cuts, aiming for 0.7 to 1.0 grams per pound of body weight provides a practical target. A 150-pound person cutting weight would shoot for 105 to 150 grams daily.
How to Spread It Across the Day
Your body doesn’t use protein as efficiently in one massive dose as it does in smaller, spaced-out servings. Research suggests that eating 0.40 to 0.55 grams of protein per kilogram of body weight per meal, spread across roughly four meals, is the most effective approach for stimulating muscle repair throughout the day. For a 180-pound person, that’s about 30 to 45 grams per meal.
Three to four protein-rich meals per day consistently outperforms eating your entire daily protein in one or two sittings. But there’s no benefit to going beyond four meals. A study in rugby players found no difference between four and six protein feedings per day for building lean mass. So four meals is the sweet spot for most people, and three works well too.
The Post-Workout Window Is Wider Than You Think
The old advice to chug a protein shake within 30 minutes of your last set overstates the urgency for most lifters. The window for your body to use protein effectively after training extends to roughly five to six hours surrounding your workout, not just the hour after.
The timing matters most when you train on an empty stomach. If you haven’t eaten for several hours before lifting, getting protein in sooner after your session is more important. But if you ate a meal with decent protein one to two hours before training, you don’t need to rush. You can base your post-workout eating on preference, convenience, and your normal meal schedule.
Total daily protein intake matters more than precisely when you eat it relative to your workout.
Hitting the Leucine Threshold
Not all protein servings are created equal when it comes to flipping the switch on muscle repair. Each meal needs to deliver enough of the amino acid leucine, which acts as a trigger for your muscles to start building new tissue. The threshold sits at around 2 to 3 grams of leucine per meal. Most whole-food protein sources hit this mark naturally if you’re eating 25 to 40 grams of protein per sitting. Eggs, chicken, Greek yogurt, beef, fish, and dairy all deliver leucine efficiently.
Plant-Based Protein Works, With One Caveat
If you eat a plant-based diet, you can build muscle just as effectively as someone using whey or other animal proteins. Studies have shown that plant-based and whey protein produce equal muscle growth when total protein and essential amino acid content are matched. The key is making sure each serving delivers at least 20 to 30 grams of protein with adequate leucine (1 to 3 grams per serving).
Some plant proteins are lower in leucine or other essential amino acids per gram compared to animal sources, so you may need slightly larger servings or strategic combinations (like pairing rice and pea protein) to hit the same amino acid profile. This isn’t a dealbreaker. It just means paying a bit more attention to variety and portion size.
Adjustments for Older Adults
After about age 60, muscles become less responsive to protein. This is called anabolic resistance, and it means older adults need more protein per meal and per day to get the same muscle-building signal that a younger person gets with less. The recommended intake for older adults is at least 1.0 to 1.2 grams per kilogram of body weight daily, and the per-meal dose that maximizes muscle repair is higher too: about 0.40 g/kg per meal compared to 0.24 g/kg for younger adults.
For a 170-pound older adult (77 kg), that means targeting at least 77 to 92 grams of protein per day, spread evenly across meals with 30 or more grams at each sitting. Spacing protein throughout the day is especially important in this age group, since skewing intake toward a single large dinner leaves the other meals below the threshold needed to stimulate muscle repair.
Is High Protein Safe?
High-protein diets are not known to cause medical problems in healthy people. The longstanding concern about kidney damage from high protein intake has not been supported by research in individuals with normal kidney function. If you have existing kidney disease, diabetes, or other chronic conditions, higher protein intakes can be harder for your body to process, and your needs should be discussed with a provider. But for generally healthy adults eating in the 1.2 to 1.6 g/kg range, kidney health is not a concern.
A Quick Reference by Body Weight
- 130 lbs (59 kg): ~95 grams per day
- 150 lbs (68 kg): ~109 grams per day
- 180 lbs (82 kg): ~131 grams per day
- 200 lbs (91 kg): ~145 grams per day
- 220 lbs (100 kg): ~160 grams per day
These numbers assume you’re eating enough total calories to support muscle gain. If you’re in a deficit, scale up toward 1.0 gram per pound of body weight to protect the muscle you already have.