How much protein do I need a day to lose weight or build muscle?
The minimum for most adults is 0.8 g of protein per kg of body weight (0.36 g per pound), but the 2025–2030 Dietary Guidelines for Americans set a higher goal of 1.2–1.6 g/kg a day.[1][2] If you're strength training to build muscle, research finds gains level off at about 1.6 g/kg a day on average.[3] For a 170-pound adult, that works out to about 93–123 g a day.
Key Takeaways
- RDA: 0.8 g/kg/day (0.36 g/lb). This is a minimum, not an optimal intake.[1]
- 2025–2030 Dietary Guidelines goal: 1.2–1.6 g/kg/day, adjusted to your calorie needs.[2]
- Building muscle: a meta-analysis of 49 trials found muscle gains leveled off around 1.6 g/kg/day. Up to about 2.2 g/kg is suggested for people trying to maximize gains.[3]
- Losing weight: more protein plus exercise helps keep lean mass while you cut calories.[4] Lifting is still the bigger driver of muscle than protein.[3]
- Spread it out: about 20–40 g per meal, every 3–4 hours.[4]
What is the minimum amount of protein I need?
The Recommended Dietary Allowance (RDA) is 0.8 g of protein per kilogram of body weight per day, or 0.36 g per pound. As Harvard Health puts it, the RDA is "the minimum amount you need to keep from getting sick," not the amount you're supposed to eat.[1] Harvard's example: a sedentary 140-pound, 50-year-old woman needs about 53 g a day to meet the RDA.[1]
The 2025–2030 Dietary Guidelines for Americans set a higher goal: 1.2 to 1.6 g per kg of body weight per day, which may vary based on your individual protein and calorie needs.[2]
How much protein per day for my weight and goal?
| Daily target | Where the number comes from | For a 170 lb (77 kg) adult |
|---|---|---|
| 0.8 g/kg (0.36 g/lb) | RDA: the baseline minimum for most adults[1] | ≈ 62 g/day |
| 1.2 g/kg | Low end of the 2025–2030 Dietary Guidelines goal[2] | ≈ 93 g/day |
| 1.6 g/kg | High end of the Dietary Guidelines goal; average plateau for muscle gain with lifting[3] | ≈ 123 g/day |
| 2.2 g/kg | Upper estimate for people trying to maximize muscle gain[3] | ≈ 170 g/day |
Math: 170 lb ÷ 2.2046 = 77.1 kg, multiplied by each target and rounded. Swap in your own weight. If you have obesity, ask your clinician or dietitian which body weight to use (see FAQ).
To convert to pounds, 1.2–1.6 g/kg works out to about 0.54–0.73 g per pound of body weight.
How much protein do I need to lose weight?
When you eat fewer calories, protein helps protect muscle. The International Society of Sports Nutrition (ISSN) position stand reviews studies where protein above the RDA was combined with calorie restriction and exercise. These studies show greater fat loss with better preservation of fat-free mass.[4] In one 21-day study it describes, people eating 1× the RDA lost the most total weight but also the largest share of fat-free mass. Groups eating 2× and 3× the RDA lost weight that was 70% and 64% fat.[4]
A practical range for most people losing weight is the Dietary Guidelines' 1.2–1.6 g/kg/day,[2] combined with strength training. Higher protein on its own isn't a magic fix. A Harvard-affiliated dietitian quoted by Harvard Health says the "verdict is still out" on protein for weight loss by itself: "Some studies support it, some studies don't."[1]
If you're losing weight with a GLP-1 medication, see how to prevent muscle loss on GLP-1s. A 2025 medical advisory gives specific protein and training targets.[5]
How much protein do I need to build muscle?
The largest analysis on this question pooled 49 randomized trials with 1,863 participants who were lifting weights. Extra protein increased gains in muscle and strength, but the benefit for fat-free mass leveled off at about 1.62 g/kg/day.[3] Because that estimate is uncertain (95% CI 1.03–2.20), the authors suggest that people trying to maximize muscle gain could aim for about 2.2 g/kg/day.[3] The ISSN position stand recommends 1.4–2.0 g/kg/day for most people who exercise.[4]
The same meta-analysis makes a point that's easy to miss: the training itself is "the much more potent stimulus." Protein adds to the gains from lifting but doesn't replace it.[3] The effect of extra protein was also smaller in older adults,[3] which is one more reason training matters as you age. For reference, the CDC recommends muscle-strengthening activity on at least 2 days a week for all adults.[6]
How much protein per meal, and when?
The ISSN position stand recommends about 0.25 g/kg per meal, or 20–40 g, spread every 3–4 hours across the day. It also notes that older adults likely need doses closer to 40 g to get the full muscle-building response.[4] Harvard Health also points out that many Americans eat most of their protein at dinner, and that spreading it out may make it more effective.[1] Exact timing matters less than your total for the day.[4]
What does that look like in food?
Approximate protein in common foods, from Harvard Health (USDA data):[1]
| Food | Protein |
|---|---|
| 3 oz tuna, salmon, haddock, or trout | 21 g |
| 3 oz cooked turkey or chicken | 19 g |
| 6 oz plain Greek yogurt | 17 g |
| ½ cup cottage cheese | 14 g |
| ½ cup cooked beans | 8 g |
| 1 cup milk | 8 g |
| 1 oz nuts | 7 g |
| 1 egg | 6 g |
Harvard also recommends looking at the whole "protein package": favor sources that are lower in saturated fat and processed carbohydrates, and don't read "eat more protein" as "eat more meat." Beans, nuts, whole grains, and dairy count too.[1]
Do I need protein powder?
No. The ISSN says active people can get enough protein from whole foods, and that supplements are simply a practical way to fill gaps.[4] Powders are useful when you're busy, traveling, or have a small appetite.
Zac and Ashley Gerard are independent Amway business owners and may earn income from Nutrilite protein products. You don't need any particular brand to hit your protein target, and you don't need powder at all if food works for you.
Can you eat too much protein?
For healthy people who exercise, the ISSN position stand found no controlled evidence that higher protein intakes harm the kidneys or liver.[4] The 2025 GLP-1 nutrition advisory is more cautious. It advises against staying at 2 g/kg/day or more for long periods because of potential adverse effects, and it notes that protein beyond what your muscles need for repair or growth can be converted to fat by the liver.[5] If you have kidney disease, talk to your doctor first. People with kidney failure benefit from protein-restricted diets.[4]
Frequently Asked Questions
How many grams of protein a day for a woman?
How much protein do I need per pound of body weight?
Should I use my current weight or my goal weight?
For people with obesity, experts haven't settled which weight to use. Using actual body weight can significantly overestimate needs. An absolute target of about 80–120 g/day is one simpler option described in a 2025 medical advisory.[5] A registered dietitian can personalize this.
Do older adults need more protein?
Sources
Every link below was opened and checked on Oct 9, 2026. Numbers in brackets in the text point to these sources.
- Harvard Health Publishing, Harvard Medical School. How much protein do you need every day? (reviewed by Howard E. LeWine, MD). https://www.health.harvard.edu/blog/how-much-protein-do-you-need-every-day-201506188096
- MedlinePlus (U.S. National Library of Medicine). Dietary Guidelines for Americans 2025–2030 (review date Feb 9, 2026). https://medlineplus.gov/ency/article/002093.htm
- Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 2018;52(6):376–384. https://bjsm.bmj.com/content/52/6/376
- Jäger R, et al. International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition, 2017;14:20. https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0177-8
- Mozaffarian D, et al. Nutritional priorities to support GLP-1 therapy for obesity: a joint Advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity / Am J Clin Nutr, 2025 (full text on PubMed Central). https://pmc.ncbi.nlm.nih.gov/articles/PMC12304835/
- Centers for Disease Control and Prevention. Adult Activity: An Overview (Physical Activity Guidelines for Americans summary). https://www.cdc.gov/physical-activity-basics/guidelines/adults.html