Most adults need at least 0.36 grams of protein per pound of body weight per day, which works out to about 55 grams for a 150-pound person. That number is the bare minimum to prevent deficiency, though. Depending on your age, activity level, and goals, you likely need more.
The Baseline: 0.8 Grams per Kilogram
The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight, or 0.36 grams per pound. For a 180-pound person, that’s roughly 65 grams a day. For someone at 140 pounds, it’s about 50 grams. This amount keeps a sedentary adult from losing muscle mass and covers basic metabolic needs, supplying about 10% of total daily calories.
The RDA is not a target for optimal health. It’s a floor. Most nutrition researchers now consider it too low for people who exercise, want to maintain muscle as they age, or are trying to lose weight without losing lean tissue.
What Active People Actually Need
If you exercise regularly, whether that’s strength training, running, cycling, or playing sports, your protein needs climb well above the RDA. The range most supported by research is 1.2 to 2.0 grams per kilogram of body weight per day, or roughly 0.55 to 0.9 grams per pound. Where you fall in that range depends on how intense your training is and whether you’re trying to build muscle or maintain it.
For a 160-pound person who lifts weights three to four times a week, that translates to roughly 88 to 144 grams per day. People focused on building muscle tend to benefit from the higher end, while endurance athletes can stay closer to the middle of the range.
Protein Needs After 65
Older adults lose muscle more easily and use dietary protein less efficiently than younger people. The PROT-AGE study group, an international panel focused on nutrition in aging, recommends that adults over 65 eat 1.0 to 1.2 grams of protein per kilogram of body weight daily just to maintain muscle mass and physical function. That’s 25 to 50% more than the standard RDA.
For older adults who exercise regularly, the recommendation rises to at least 1.2 grams per kilogram. Those dealing with acute or chronic illness need even more: 1.2 to 1.5 grams per kilogram per day. For a 155-pound person with a chronic condition, that means roughly 84 to 106 grams daily, a meaningful jump from the 56 grams the standard RDA would suggest.
This higher intake helps counteract sarcopenia, the gradual loss of muscle that accelerates after 65 and contributes to falls, frailty, and loss of independence.
Pregnancy and Breastfeeding
Protein needs rise during pregnancy, but the increase is modest in the first trimester and becomes significant only later. International guidelines from the WHO recommend an additional 1 gram per day in the first trimester, 9 grams in the second, and 31 grams in the third. A pregnant woman who would normally need about 55 grams daily would need closer to 85 grams by the final months of pregnancy.
During breastfeeding, the extra requirement stays elevated at about 19 grams per day for the first six months, dropping to around 13 grams after that if you’re partially breastfeeding. These numbers sit on top of your normal baseline, so a breastfeeding mother weighing 150 pounds would aim for roughly 70 to 75 grams daily.
How to Calculate Your Number
The simplest approach is to multiply your body weight by the gram-per-pound figure that matches your situation:
- Sedentary adult: 0.36 g per pound (0.8 g/kg)
- Recreationally active adult: 0.55 to 0.7 g per pound (1.2 to 1.6 g/kg)
- Serious strength training or muscle gain: 0.7 to 0.9 g per pound (1.6 to 2.0 g/kg)
- Adults over 65: 0.45 to 0.55 g per pound (1.0 to 1.2 g/kg)
- Weight loss while preserving muscle: 0.55 to 0.7 g per pound (1.2 to 1.6 g/kg)
If you’re significantly overweight, using your goal body weight rather than your current weight gives a more realistic target. Someone who weighs 250 pounds but is aiming for 180 would calculate based on 180 pounds, landing at roughly 65 to 126 grams depending on activity level.
How Much Protein per Meal
Your body can only use so much protein at once for building and repairing muscle. Research shows that muscle protein synthesis, the process that repairs and grows muscle fibers, maxes out at around 30 grams of protein in a single meal. Eating 60 grams in one sitting doesn’t double the muscle-building response compared to 30 grams.
That said, the picture is slightly more nuanced. Studies on meal frequency found that eating two or more meals containing 30 to 45 grams of protein produced the strongest association with leg muscle mass and strength. The benefit plateaued at around 45 grams per meal for people eating at least two high-protein meals a day. For someone eating only one protein-rich meal, the ceiling was closer to 30 grams.
The practical takeaway: spreading your protein across three or four meals tends to be more effective than loading it into one or two. If your daily target is 100 grams, eating 25 to 35 grams at each of three meals plus a protein-rich snack is a better strategy than having a 10-gram breakfast and a 70-gram dinner.
What 30 Grams of Protein Looks Like
Hitting your target is easier when you can visualize portion sizes. Each of these provides roughly 30 grams of protein:
- Chicken breast: about 4 ounces cooked (roughly the size of a deck of cards)
- Greek yogurt: one and a half cups of plain nonfat
- Eggs: five large eggs
- Canned tuna: one standard 5-ounce can
- Lentils: about one and a half cups cooked
- Tofu: roughly 14 ounces of firm tofu
- Whey protein powder: one typical scoop
Most people already eat enough protein at dinner. The meals that tend to fall short are breakfast and lunch. Adding eggs, yogurt, or a handful of nuts to breakfast and including beans, chicken, or cheese at lunch can close the gap without overhauling your diet.