The baseline recommendation for protein is 0.8 grams per kilogram of body weight per day, or about 0.36 grams per pound. For a 150-pound person, that works out to roughly 54 grams daily. But that number represents the minimum to prevent deficiency in a sedentary adult, not the amount that’s optimal for building muscle, losing fat, or aging well. Depending on your goals and activity level, you may need two or even three times that amount.
The Baseline: 0.8 Grams Per Kilogram
The official Recommended Dietary Allowance sets protein at 0.8 g/kg/day for healthy adults of all ages. In absolute terms, that translates to 46 grams per day for adult women and 56 grams for adult men. The acceptable range for protein as a share of total calories is 10 to 35 percent.
At the low end, this supplies about 10 percent of daily calories for a moderately active person. Most nutrition researchers now view 0.8 g/kg as a floor rather than a target. It prevents clinical protein deficiency, but it doesn’t optimize muscle maintenance, recovery, or body composition. Almost every population with a specific physical goal benefits from eating above this line.
How Much for Building Muscle
If you lift weights and want to gain muscle, the well-supported range is 1.4 to 2.0 grams per kilogram per day (about 0.64 to 0.91 grams per pound). The International Society of Sports Nutrition considers this sufficient for most exercising individuals to build and maintain muscle mass. For a 180-pound lifter, that’s roughly 115 to 164 grams of protein daily.
A large meta-analysis of randomized controlled trials found a clear dose-response relationship: for every additional 0.1 g/kg/day of protein consumed, lean body mass increased. But the gains weren’t linear. Below 1.3 g/kg/day, each small increase in protein produced meaningful muscle gains. Above 1.3 g/kg/day, the benefit per additional gram dropped sharply, though resistance training helped squeeze more out of higher intakes. In practical terms, you get the biggest bang for your buck by hitting at least 1.3 g/kg, and diminishing but still real returns up to about 2.0 g/kg.
There’s even some evidence that very high intakes above 3.0 g/kg/day may promote fat loss in resistance-trained individuals without negative effects on body composition. That said, most people don’t need to go that high to see results.
How Much for Endurance Athletes
Runners, cyclists, swimmers, and other endurance athletes have elevated protein needs, though not quite as high as strength athletes. The current recommendation for endurance runners is 1.2 to 1.4 grams per kilogram per day. For a 140-pound runner, that’s about 76 to 89 grams daily.
Post-workout nutrition matters here too. A recovery meal should contain 15 to 30 grams of high-quality protein paired with carbohydrates in roughly a 3:1 carb-to-protein ratio. This combination supports both glycogen replenishment and muscle repair.
How Much During Weight Loss
When you’re eating in a calorie deficit, your body doesn’t just burn fat. It also breaks down muscle for energy, which slows your metabolism and makes it harder to keep weight off long term. Protein is the main lever you can pull to protect against this.
Guidelines for muscle preservation during weight loss recommend approximately 0.7 to 1.0 grams of protein per pound of body weight, which is notably higher than the standard RDA. For someone at 200 pounds aiming to lose fat, that means 140 to 200 grams per day. This is one of the highest recommended ranges across any goal, reflecting how important protein becomes when calories are restricted. The satiating effect of protein also helps with appetite control, making it easier to stick with a deficit.
How Much for Adults Over 65
Aging muscles become less efficient at using dietary protein, a phenomenon researchers call “anabolic resistance.” The same 0.8 g/kg that technically meets minimum needs in a younger adult often isn’t enough to prevent gradual muscle loss in older adults. The result, over years, is sarcopenia: the progressive loss of muscle mass and strength that increases fall risk and reduces independence.
Researchers recommend that older adults consume 1.0 to 1.2 grams of protein per kilogram of body weight daily. For a 160-pound older adult, that’s roughly 73 to 87 grams per day. Spreading protein across meals rather than loading it into dinner appears to be especially important for this age group.
How to Spread Protein Across the Day
Your body can only use so much protein for muscle building at one time. Research shows that meals containing at least 30 grams of protein are needed to maximally stimulate muscle protein synthesis. Portions providing 30 to 45 grams per meal produced the strongest association with leg lean mass and strength in study participants. Eating above 45 grams in a single sitting didn’t add further benefit.
The practical takeaway: aim for 30 to 45 grams of protein at each of your main meals, distributed every three to four hours across the day. If you eat three meals, that’s 90 to 135 grams just from meals, with snacks filling in the rest depending on your target. A pre-sleep serving of 30 to 40 grams of slow-digesting protein (like cottage cheese or a casein-based shake) can support overnight muscle repair and slightly boost your metabolic rate while you sleep.
Each serving should include a full range of essential amino acids. Meat, poultry, fish, eggs, dairy, and quinoa all qualify. Plant-based eaters can combine legumes with grains or use protein-dense options like tofu and tempeh to hit the same amino acid profile.
Quick Reference by Goal
- General health (sedentary adult): 0.8 g/kg (0.36 g/lb)
- Older adults (65+): 1.0 to 1.2 g/kg (0.45 to 0.55 g/lb)
- Endurance athletes: 1.2 to 1.4 g/kg (0.55 to 0.64 g/lb)
- Muscle building with resistance training: 1.4 to 2.0 g/kg (0.64 to 0.91 g/lb)
- Fat loss while preserving muscle: 1.5 to 2.2 g/kg (0.7 to 1.0 g/lb)
To convert your weight: divide your weight in pounds by 2.2 to get kilograms, then multiply by the g/kg target for your goal. A 170-pound person aiming for 1.6 g/kg, for example, would calculate 170 ÷ 2.2 = 77.3 kg, then 77.3 × 1.6 = about 124 grams of protein per day.