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. This is notably higher than the official Recommended Dietary Allowance of 0.8 g/kg, which represents the bare minimum to prevent deficiency, not the amount that actually preserves lean tissue over time.
The gap between the RDA and what your muscles actually need is significant. A large body of evidence from randomized controlled trials now suggests that intakes approximating twice the RDA promote preservation of lean body mass and functional ability, especially as you age. Your exact number depends on your activity level, age, whether you’re losing weight, and where your protein comes from.
Your Baseline Number by Activity Level
If you’re a generally healthy adult who isn’t doing intense exercise, aiming for 1.2 to 1.6 g/kg of body weight per day gives you a strong foundation for muscle maintenance. At the lower end, a sedentary 150-pound person (68 kg) needs about 82 grams daily. At the upper end, that same person would target around 109 grams.
If you exercise regularly, especially with resistance training, your needs climb. Active individuals benefit from 1.4 to 2.0 g/kg per day. For that same 150-pound person, that’s 95 to 136 grams. The higher end of this range matters most when you’re training hard or trying to add muscle, but even for pure maintenance, staying above 1.4 g/kg gives your muscles consistent building material to work with.
Here’s a quick reference by body weight, using the 1.2 to 1.6 g/kg range for general maintenance:
- 130 lbs (59 kg): 71 to 94 g/day
- 150 lbs (68 kg): 82 to 109 g/day
- 170 lbs (77 kg): 92 to 123 g/day
- 200 lbs (91 kg): 109 to 146 g/day
Why the RDA Falls Short
The RDA of 0.8 g/kg was designed to meet the minimum protein needs of 97.5% of the population. It prevents outright deficiency. It does not optimize muscle retention. The Protein Summit 2.0, a gathering of nutrition researchers, highlighted a growing consensus that intakes around 1.6 g/kg offer measurable benefits for body composition, appetite regulation, and metabolic health that the RDA simply doesn’t account for.
Data from middle-aged adults supports this directly: consuming more than 1.2 g/kg per day during midlife appears to be advantageous for maintaining muscle mass into later years. If you’ve been eating at or near the RDA and wondering why you’re losing tone despite staying active, insufficient protein is a likely contributor.
Adjustments for Adults Over 50
Aging muscles become less efficient at using dietary protein. This phenomenon, called anabolic resistance, means older adults need more protein per meal and per day to get the same muscle-preserving effect that younger adults get from smaller amounts. Experts recommend older adults consume 1.2 to 1.6 g/kg daily, with some guidelines starting at 1.0 g/kg as a floor.
Per-meal amounts matter more here too. Younger adults can trigger a strong muscle-building response from about 0.24 g/kg of protein in a single meal (roughly 16 to 20 grams for most people). Older adults need about 0.40 g/kg per meal to hit the same threshold, which translates to 30 grams or more per sitting. This is partly because older muscles need about 3 grams of leucine, a specific amino acid, to fully activate repair processes. A typical 20-gram serving of protein only delivers about 2 grams of leucine, which falls short.
Protein Needs During Weight Loss
When you’re eating fewer calories than you burn, your body doesn’t just tap into fat stores. It also breaks down muscle for energy, and the less protein you eat, the more muscle you lose. This is why people who crash diet without attention to protein often end up lighter on the scale but weaker and softer in the mirror.
To preserve muscle during a caloric deficit, aim for 0.7 to 1.0 grams per pound of body weight. That’s considerably higher than maintenance recommendations, and intentionally so. A 160-pound person cutting calories should target 112 to 160 grams of protein per day. Combined with resistance training, this range minimizes muscle loss and keeps your metabolism from slowing as dramatically as it otherwise would.
How to Spread Protein Across the Day
Total daily protein intake is the single most important factor for muscle maintenance. If you hit your daily target, you’re doing the most important thing right, regardless of how you split it up. That said, distribution across meals can offer an additional edge, particularly for older adults or people eating on the lower end of their protein range.
Research on meal dosing found that consuming one to two meals per day with 30 to 45 grams of protein produced the strongest association with leg lean mass and muscle strength. Below 30 grams per meal, the muscle-building signal is weaker. Above about 45 grams in a single sitting, the benefit plateaus. Your body can still use the extra protein for other functions, but it won’t drive additional muscle repair.
A practical approach: aim for at least 30 grams of protein at two or three meals rather than loading 80 grams at dinner and eating 10 grams at breakfast. If you’re already eating plenty of total protein, though, don’t stress over perfect distribution. The total matters more.
Plant Protein vs. Animal Protein
Plant proteins are less digestible than animal proteins. Animal sources like meat, eggs, and dairy are absorbed at rates of 90% to 95%, while plant proteins in their whole-food form land closer to 75% to 80%. Plant proteins also contain lower concentrations of the essential amino acids that drive muscle repair, particularly leucine.
To put this in concrete terms: 25 grams of whey protein delivers about 2.7 grams of leucine, which is enough to fully activate muscle repair in most adults. To get that same 2.7 grams of leucine from plant sources, you’d need to eat 38 grams of pea protein, 40 grams of soy protein, or 47 grams of oat protein. Hemp protein requires the most at 105 grams to reach the same leucine content.
None of this means plant-based diets can’t maintain muscle. They can. But if you eat mostly or entirely plant-based, aim for the higher end of protein recommendations. For active individuals on plant-based diets, targeting 1.6 to 2.0 g/kg per day compensates for the lower digestibility and amino acid density. Combining different plant protein sources at meals (grains with legumes, for example) helps ensure you’re getting the full range of essential amino acids your muscles need. Eating a greater volume of protein-rich plant foods, enough to deliver at least 20 grams of protein per meal, can effectively stimulate muscle repair even without animal products.
Putting It All Together
For a straightforward starting point, multiply your body weight in pounds by 0.7. That gives you a reasonable daily protein target in grams for muscle maintenance. If you’re over 50, very active, eating mostly plant-based, or losing weight, multiply by 0.8 to 1.0 instead.
Spread that protein across at least two meals with 30 or more grams each. Prioritize whole protein sources that are rich in essential amino acids, whether that’s chicken, fish, eggs, Greek yogurt, tofu, lentils, or a combination. Track your intake for a few days to see where you actually land. Most people who’ve never counted are surprised to find they’re eating less protein than they assumed, especially at breakfast and lunch.