Most adults need between 1.2 and 1.6 grams of protein per kilogram of body weight per day to maintain muscle mass. For a 170-pound (77 kg) person, that works out to roughly 92 to 123 grams of protein daily. The official minimum recommendation of 0.8 g/kg/day is enough to prevent deficiency, but research consistently shows it falls short of what’s needed to actually preserve lean tissue over time, especially if you exercise or are over 65.
The Baseline: 0.8 g/kg Is Not Enough
Government guidelines in the U.S., Canada, and Europe all set the recommended protein intake at 0.8 to 0.83 g/kg of body weight per day. This number was designed to maintain nitrogen balance in about 98% of the population, which is a minimal threshold for preventing protein deficiency. It was never intended as an optimal target for keeping muscle.
A large meta-analysis in the Journal of Cachexia, Sarcopenia and Muscle found that intakes of 1.2 to 1.6 g/kg/day were needed to actually maintain or gain lean body mass in healthy adults. For people under 65 who do resistance training, the effective threshold was at or above 1.6 g/kg/day. For adults over 65, benefits showed up at a slightly lower range of 1.2 to 1.59 g/kg/day, likely because older adults respond to protein differently and need to prioritize it more carefully across meals.
How Your Age Changes the Target
Muscle loss accelerates with age. Starting around your 30s, you can lose 3 to 8% of muscle mass per decade, and the rate picks up after 60. The body becomes less efficient at using dietary protein to repair and build muscle tissue, a phenomenon researchers call “anabolic resistance.” This means older adults need more protein per meal to get the same muscle-building response a younger person would.
A 2025 study in Frontiers in Nutrition measured protein requirements directly in adults aged 65 to 81 who already had measurable muscle loss. The estimated requirement for this group was 1.21 g/kg/day on average, with the recommended safe intake set at 1.54 g/kg/day. For those without existing muscle loss, the requirement was lower at about 1.38 g/kg of fat-free mass per day. The takeaway: if you’re over 65, aiming for at least 1.2 g/kg/day is a reasonable floor, and going up to 1.5 g/kg/day provides a stronger safety margin.
Protein Needs for Active People
If you exercise regularly, your protein needs climb higher. The International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg/day for most exercising individuals looking to build or maintain muscle. That range covers both endurance and strength training, though the emphasis differs. Strength and power athletes tend to benefit from the upper end, while endurance athletes can focus on the lower-to-middle range alongside adequate carbohydrate intake.
During a calorie deficit, the stakes get higher. When you’re eating fewer calories than you burn, your body is more likely to break down muscle for energy. Research shows that protein intake above 1.3 g/kg/day helps preserve muscle mass during weight loss, while intake below 1.0 g/kg/day significantly raises the risk of losing it. For resistance-trained individuals on a serious cut, intakes as high as 2.3 to 3.1 g/kg/day have been shown to maximize lean mass retention.
How to Spread Protein Across Your Day
Total daily protein matters most, but how you distribute it across meals makes a real difference. Each time you eat protein, you trigger a burst of muscle protein synthesis that lasts a few hours and then tapers off. To keep that signal firing throughout the day, research suggests eating at least four protein-containing meals, each providing about 0.4 g/kg of body weight. For a 170-pound person, that’s roughly 30 to 35 grams per meal.
This per-meal target lines up with the amount of the amino acid leucine needed to fully activate muscle repair. Older adults need about 3 to 4 grams of leucine per meal to reach that threshold, which corresponds to roughly 25 to 30 grams of high-quality protein. Younger adults can hit it with slightly less. Eating a large portion of your daily protein in a single meal while skimping at others is less effective than spreading it evenly, even if the daily total is the same.
A pre-sleep protein dose of 30 to 40 grams, particularly from slow-digesting sources like casein (found in dairy), has been shown to increase overnight muscle protein synthesis and boost metabolic rate without interfering with fat burning.
Plant-Based Diets Require More Protein
If you get most of your protein from plants, you likely need to eat more of it to match the muscle-maintaining effect of animal protein. Plant proteins are less digestible than animal sources, contain less leucine, and are often low in one or more essential amino acids like lysine or the sulfur-containing amino acids. This means a smaller percentage of the protein you eat actually gets used for muscle repair.
Research shows that eating at least 30 grams of plant-based protein per meal can largely close this gap. The practical strategy is straightforward: increase your total intake and combine different plant sources (legumes, grains, soy, seeds) to cover the full spectrum of essential amino acids. If you’re eating a fully plant-based diet, adding roughly 10 to 20% more total protein compared to an omnivore’s target is a reasonable adjustment.
Quick Reference by Body Weight
- 130 lbs (59 kg): 71 to 95 g/day for maintenance; 83 to 118 g/day if active
- 150 lbs (68 kg): 82 to 109 g/day for maintenance; 95 to 136 g/day if active
- 170 lbs (77 kg): 92 to 123 g/day for maintenance; 108 to 154 g/day if active
- 200 lbs (91 kg): 109 to 146 g/day for maintenance; 127 to 182 g/day if active
- 220 lbs (100 kg): 120 to 160 g/day for maintenance; 140 to 200 g/day if active
These ranges use 1.2 to 1.6 g/kg for general maintenance and 1.4 to 2.0 g/kg for active individuals. If you’re in a calorie deficit, lean toward the higher end. If you’re over 65, treat 1.2 g/kg as your minimum rather than a middle target.