Most people who lift weights need between 1.2 and 1.7 grams of protein per kilogram of body weight per day to maximize muscle growth. For a 180-pound (82 kg) person, that works out to roughly 98 to 139 grams of protein daily. Where you fall in that range depends on your training intensity, age, body composition goals, and whether you’re eating in a caloric deficit.
The General Target for Muscle Growth
The most widely cited range for people who regularly lift weights is 1.2 to 1.7 grams per kilogram of body weight per day. That range covers everything from moderate recreational lifting to serious strength training. If you’re newer to resistance training or lifting at moderate intensity, the lower end of that range is likely sufficient. If you’re training hard four or more days per week and actively trying to add size, aim closer to the upper end.
In pounds, a simpler rule of thumb lands at roughly 0.7 to 1.0 grams per pound of body weight. That math is easier and produces numbers close enough to the per-kilogram recommendations that the difference is negligible in practice. For most lifters, hitting somewhere around 0.8 grams per pound consistently is a solid, well-supported target.
One thing worth understanding: there appears to be a ceiling. Research on adults with overweight and obesity found that protein intake above 1.3 g/kg/day helped increase muscle mass, while intake below 1.0 g/kg/day was associated with muscle loss. But pushing dramatically higher, say past 2.2 g/kg, hasn’t shown clear additional muscle-building benefits in most studies. More protein isn’t wasted, but the extra gains taper off significantly once you’ve met that 1.6 to 1.7 g/kg threshold.
Why You Need More Protein After 60
As you age, your body becomes less efficient at turning dietary protein into new muscle tissue. This phenomenon, called anabolic resistance, means that the same meal that would trigger robust muscle repair in a 30-year-old produces a weaker response in a 65-year-old. Several things contribute to this: your gut absorbs fewer amino acids from each meal, blood flow to muscles after eating decreases, and the chemical signals that kick off muscle repair become sluggish.
For healthy adults over 65, experts at the European Society for Clinical Nutrition and Metabolism recommend at least 1.0 to 1.2 g/kg/day just to maintain muscle mass. That’s notably higher than the standard recommendation of 0.8 g/kg for the general population. Older adults dealing with chronic illness may need 1.2 to 1.5 g/kg/day, and those recovering from severe illness or injury may need even more. If you’re over 60 and actively strength training to build muscle, aiming for the higher end of the general muscle-building range (1.5 to 1.7 g/kg) makes sense to overcome that blunted response.
Protein Needs During a Caloric Deficit
If you’re trying to lose fat while keeping (or building) muscle, protein becomes even more important. When your body is taking in fewer calories than it burns, it looks for energy wherever it can find it, and muscle tissue is on the menu unless you give it a reason to hold on. That reason is protein, combined with resistance training.
Guidelines for preserving muscle during weight loss recommend approximately 0.7 to 1.0 grams per pound of body weight. That’s the higher end of the muscle-building range, and it’s intentionally aggressive. During a caloric deficit, a larger share of the protein you eat gets burned for energy instead of being used for muscle repair, so you need to compensate by eating more of it. If you’re currently cutting calories and lifting, this is not the time to let your protein intake slide.
Plant Protein vs. Animal Protein
Not all protein sources trigger the same muscle-building response. Plant-based proteins are generally less digestible than animal proteins, partly because of their molecular structure. Plant proteins contain more of a folded shape (beta-sheet conformation) that resists breakdown in the digestive tract. Fiber and naturally occurring compounds like phytic acid and tannins further reduce how much of the protein your body can actually absorb and use.
The amino acid profiles also differ in meaningful ways. Muscle growth is heavily driven by essential amino acids, particularly leucine, which acts as the primary trigger for muscle protein synthesis. Animal-based proteins contain about 8.8% leucine on average, with dairy proteins exceeding 10%. Plant-based proteins average around 7.1%. That gap matters at the level of individual meals. Studies comparing soy protein to whey or casein have found that amino acids from soy are more likely to be broken down and excreted rather than directed toward muscle repair.
Plant proteins also tend to be low in specific essential amino acids. Legumes like soybeans, peas, and lentils are low in sulfur-containing amino acids, while grains like wheat and corn are low in lysine. Neither deficiency is a problem if you eat a variety of plant protein sources throughout the day, but relying on a single source can leave gaps. Using standardized protein quality scores (PDCAAS and DIAAS), virtually all plant proteins tested so far score below 100%, while most animal proteins meet or exceed that mark.
None of this means you can’t build muscle on a plant-based diet. It does mean you may benefit from eating toward the higher end of the protein range, combining complementary protein sources (legumes with grains, for example), and paying attention to total leucine intake. Some people find that supplementing with a blended plant protein powder that includes pea, rice, and soy covers most of the amino acid gaps.
How to Distribute Protein Throughout the Day
Total daily protein matters more than meal timing, but distribution still plays a role. Your body can only use so much protein for muscle repair in a single sitting. Spreading your intake across three to four meals, each containing 25 to 40 grams of protein, tends to produce better results than eating most of your protein in one large meal. This is especially true for older adults, whose muscle-building response to a single dose of protein is already reduced.
A post-workout meal or shake containing at least 20 to 30 grams of protein is a reasonable practice, but the window isn’t as narrow as gym culture suggests. Eating a protein-rich meal within a couple of hours of training is more than sufficient. If you trained in a fasted state, prioritizing protein sooner rather than later makes more sense, but for most people who ate a meal before their workout, the urgency is low.
Is High Protein Intake Safe?
For healthy people, high-protein diets are not known to cause medical problems. The longstanding concern about protein damaging kidneys has not held up in research on people with normal kidney function. Your kidneys handle the byproducts of protein metabolism as part of their normal job, and eating 1.5 or even 2.0 g/kg per day does not appear to strain them.
The caveat is for people who already have kidney disease. In that case, high protein intake can worsen kidney function because the kidneys may struggle to clear the waste products of protein breakdown. If you have known kidney issues, your intake should be guided by your medical team rather than general muscle-building recommendations.
Practical Targets by Body Weight
- 140 lbs (64 kg): 77 to 109 g/day for muscle building; up to 140 g/day if cutting
- 160 lbs (73 kg): 88 to 124 g/day for muscle building; up to 160 g/day if cutting
- 180 lbs (82 kg): 98 to 139 g/day for muscle building; up to 180 g/day if cutting
- 200 lbs (91 kg): 109 to 155 g/day for muscle building; up to 200 g/day if cutting
- 220 lbs (100 kg): 120 to 170 g/day for muscle building; up to 220 g/day if cutting
These numbers assume you’re at a relatively normal body fat percentage. If you carry significant excess body fat, using your lean body mass or your goal weight for the calculation will give you a more accurate target than using your total body weight.