Most healthy adults need between 1.2 and 1.6 grams of protein per kilogram of body weight per day to maintain muscle mass. That translates to roughly 82 to 109 grams daily for a 150-pound person. The official Recommended Dietary Allowance of 0.8 g/kg/day is designed to prevent deficiency, not to optimize muscle preservation, and many researchers now consider it a floor rather than a target.
The RDA vs. What Your Muscles Actually Need
Government guidelines in the U.S., Canada, and Europe all set the protein recommendation at 0.8 to 0.83 g/kg of body weight per day. This number represents the minimum intake needed to maintain nitrogen balance and prevent muscle loss in 97.5% of the adult population. It was never intended as the amount for optimal muscle health.
A growing body of evidence points to 1.2 to 1.6 g/kg/day as the range that better supports lean body mass in both younger and older adults. A 2022 systematic review and meta-analysis in the Journal of Cachexia, Sarcopenia and Muscle confirmed that this higher range helps maintain or even improve lean body mass across age groups. For people who strength train, the International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg/day, with those focused on strength and power aiming toward the upper end.
How Activity Level Changes the Target
If you’re mostly sedentary, sticking closer to 1.2 g/kg/day is likely sufficient to hold onto the muscle you have. Eating below the RDA of 0.8 g/kg/day, even when you’re eating enough total calories, leads to measurable muscle loss of roughly 0.2 to 0.5% per week.
If you exercise regularly, the picture shifts. Endurance athletes (runners, cyclists, swimmers) do well at the lower end of the sports nutrition range, around 1.4 g/kg/day. People doing a mix of activities land in the middle, around 1.4 to 1.7 g/kg/day. And if you lift weights consistently, aiming for 1.6 to 2.0 g/kg/day gives your muscles the best chance of full recovery and maintenance. Reaching at least 1.6 g/kg/day also appears necessary for building lower-body strength specifically.
Protein Needs During Weight Loss
Cutting calories puts your muscle at risk. Your body, short on energy, will break down muscle tissue for fuel unless you give it a strong reason not to. That reason is protein, paired with resistance training.
During a caloric deficit, protein needs jump to roughly 1.0 to 1.5 g/kg/day for sedentary individuals and above 1.2 g/kg/day (at least 1.5 times the RDA) for those who exercise. Doubling the RDA to 1.6 g/kg/day has been shown to effectively preserve muscle mass during active weight loss. The protective effect is real but modest: high protein intake during a diet typically saves about 400 to 800 grams of lean mass compared to lower intakes. That may sound small, but over repeated diet cycles or extended cuts, the cumulative difference adds up considerably.
Why Older Adults Need More
Aging muscles become less responsive to protein. The same meal that triggers robust muscle repair in a 25-year-old produces a blunted response in a 65-year-old. There is broad agreement among researchers that adults over 60 benefit from intakes above the standard 0.8 g/kg/day to slow the progressive loss of muscle mass that comes with aging.
One practical difference shows up at the meal level. Younger adults get a strong muscle-building signal from as little as 20 grams of protein in a single sitting. Older adults need closer to 30 grams per meal, with at least 2.8 grams of leucine (an amino acid concentrated in dairy, eggs, meat, and soy) to cross the threshold that triggers meaningful muscle repair.
Spreading Protein Across Meals Matters
Total daily protein gets the most attention, but how you distribute it throughout the day also affects muscle maintenance. A crossover study in The Journal of Nutrition compared two eating patterns: one where protein was spread evenly across breakfast, lunch, and dinner (about 30 grams each), and another where most protein was loaded into dinner (over 60 grams at the evening meal, with only about 10 grams at breakfast). Both patterns delivered roughly 90 to 94 grams of protein per day.
The results were striking. The even distribution produced 25% higher rates of muscle protein synthesis over 24 hours compared to the dinner-heavy pattern, and this difference held up after a full week on each diet. The takeaway is straightforward: if you’re eating 30 grams of protein at dinner and 10 grams at breakfast, simply redistributing what you already eat can meaningfully improve muscle maintenance without changing your total intake.
Plant vs. Animal Protein
Plant proteins can absolutely support muscle maintenance, but they’re not identical to animal sources. A 2025 systematic review and meta-analysis of randomized controlled trials found that animal protein produced modestly better muscle mass outcomes overall. The gap was small when comparing animal protein to soy, but widened notably when comparing animal protein to non-soy plant sources like rice, oat, chia, and potato protein.
The reason comes down to amino acid profiles. Most individual plant proteins are lower in one or more essential amino acids and are slightly less digestible than animal sources. If you eat exclusively plant-based, aiming for the higher end of the recommended range (closer to 1.6 g/kg/day), combining complementary protein sources throughout the day, and including soy or other leucine-rich options can help close the gap.
Practical Numbers by Body Weight
Here’s what the 1.2 to 1.6 g/kg/day range looks like in practice:
- 130 lbs (59 kg): 71 to 94 g of protein per day
- 150 lbs (68 kg): 82 to 109 g per day
- 180 lbs (82 kg): 98 to 131 g per day
- 200 lbs (91 kg): 109 to 146 g per day
- 220 lbs (100 kg): 120 to 160 g per day
If you’re significantly overweight, using your target or lean body weight rather than your current weight gives a more accurate estimate, since body fat doesn’t drive protein requirements.
For most people trying to maintain muscle, aiming for three to four meals with 25 to 40 grams of protein each covers both the total daily target and the per-meal threshold that maximizes muscle protein synthesis. That looks like a palm-sized portion of meat or fish, a cup of Greek yogurt with nuts, or a generous serving of tofu with beans. The ceiling for useful protein per meal exists: research shows that muscle-building signals increase sharply up to about 20 grams of protein per meal in younger adults, then plateau, with minimal additional benefit from jumping to 40 grams in a single sitting.