Most women need between 46 and 75 grams of protein per day, depending on body weight, activity level, and life stage. The baseline recommendation for all adults is 0.8 grams of protein per kilogram of body weight. For a 140-pound (64 kg) woman, that works out to about 51 grams daily. But that number is a minimum to prevent deficiency, not necessarily the amount that keeps you feeling strong, full, and healthy over the long term.
The Baseline Number and Why It’s Often Too Low
The standard recommendation of 0.8 g/kg per day has been essentially unchanged for over 70 years. It doesn’t distinguish between men and women or between a 25-year-old and a 70-year-old. It was set to meet the minimum needs of most healthy, sedentary adults, not to optimize muscle retention, bone health, or satiety. For many women, especially those who exercise, are losing weight, or are over 50, this baseline falls short.
A more practical starting point for most active or health-conscious women is 1.2 g/kg per day. For that same 140-pound woman, that’s about 77 grams. The right number for you depends on what your body is doing right now.
Protein Needs by Activity Level
If you work out regularly, your protein needs are roughly double the baseline. A systematic review of pre-menopausal female athletes found that the requirements are surprisingly similar across exercise types. Women doing cardio-based exercise like running or cycling need about 1.28 to 1.63 g/kg per day. Women doing resistance training need around 1.49 g/kg per day, and those in intermittent sports (think soccer, basketball, HIIT) need about 1.41 g/kg per day. For a 150-pound woman, that range translates to roughly 87 to 111 grams daily.
Even if you wouldn’t call yourself an athlete, consistent exercise of 60 to 90 minutes a few times a week puts you in this category. If you’re lifting weights with any goal of building or maintaining muscle, aiming for 1.4 to 1.6 g/kg is a solid target.
Protein for Weight Loss
Protein becomes especially important when you’re eating fewer calories. A 12-week study of women with BMIs between 26 and 37 compared a higher-protein diet (30% of calories from protein) against a normal-protein diet (18% of calories). Both groups lost weight, but the higher-protein group lost significantly less muscle: 1.5 kg of lean mass versus 2.8 kg. That matters because muscle drives your metabolism. Losing it makes it harder to keep weight off later.
The higher-protein group also reported better satiety and more enjoyment of their food throughout the diet. If you’re cutting calories, getting 25 to 30% of those calories from protein helps you feel less deprived and protects the muscle you’ve built. On a 1,500-calorie diet, that’s roughly 94 to 112 grams of protein per day.
After 50: Why Protein Needs Go Up
As women age, the body becomes less efficient at using dietary protein to maintain muscle. This gradual loss of muscle mass, called sarcopenia, accelerates after menopause. An international expert panel recommended that adults over 65 consume 1.0 to 1.2 g/kg of protein per day, with even higher intakes for those who are physically active. The current evidence suggests that at least 1.2 g/kg per day is needed to maintain optimal muscle function in older adults.
Pairing that protein intake with resistance exercise twice a week has strong evidence behind it for reducing age-related muscle loss. Neither protein alone nor exercise alone is as effective as the combination. For a 130-pound woman over 65, the target is at least 71 grams per day, and closer to 85 or more if she’s active.
Pregnancy and Breastfeeding
Protein needs increase progressively during pregnancy. The additional protein recommended beyond normal intake is minimal in the first trimester (less than 1 gram extra per day), then jumps to about 10 extra grams per day in the second trimester and roughly 31 extra grams per day in the third trimester. That third-trimester increase is substantial. A woman who normally needs 55 grams would need about 86 grams daily in late pregnancy. Protein needs remain elevated during breastfeeding as well, generally by about 15 to 20 grams above baseline.
How to Spread Protein Across the Day
Your body can only use so much protein at once for muscle repair. The research suggests that about 20 to 25 grams of high-quality protein per meal maximally stimulates muscle building in younger adults. A more individualized target is 0.4 g/kg per meal across at least four eating occasions per day. For a 140-pound woman, that’s about 26 grams per meal.
This is where many women fall short. A common pattern is a low-protein breakfast (toast, fruit, coffee), a moderate lunch, and a large dinner. By the time you eat most of your protein at 7 PM, you’ve missed several opportunities to fuel muscle repair earlier in the day. Distributing protein more evenly, with 20 to 30 grams at each meal plus a protein-rich snack, is more effective than loading it all into one sitting.
For older women, the threshold per meal may be slightly higher. Studies suggest that about 25 to 30 grams of protein per meal, providing roughly 3 to 4 grams of the amino acid leucine, is needed to optimally stimulate muscle repair in older adults. A leucine-enriched protein source produced significantly greater muscle protein synthesis than the same total protein with less leucine, suggesting that protein quality matters more as you age. Animal proteins, soy, and dairy tend to be the richest leucine sources.
What Enough Protein Actually Looks Like
Hitting 80 to 100 grams of protein can sound intimidating until you see what it looks like in real food. A piece of chicken, fish, or meat the size of a deck of cards contains about 21 grams. A single egg has 6 grams. A cup of Greek yogurt provides 12 to 18 grams. Half a cup of cottage cheese delivers 14 grams. Half a cup of lentils or black beans gives you 8 to 9 grams.
Here’s a sample day that reaches about 90 grams without protein shakes:
- Breakfast: Two eggs (12 g) plus Greek yogurt (15 g) = 27 g
- Lunch: 3 oz chicken on a salad (21 g) with half a cup of beans (8 g) = 29 g
- Snack: Cottage cheese, half cup (14 g) = 14 g
- Dinner: 3 oz salmon (21 g) with quinoa, one-third cup (6 g) = 27 g
If you eat plant-based, it takes more planning but is entirely doable. Edamame, lentils, tofu, beans, nuts, and high-protein cereals can all contribute meaningfully. Dry roasted edamame packs 13 grams per ounce, and hummus offers 7 grams per third of a cup. Combining several plant sources throughout the day covers your amino acid bases.
Upper Limits and Safety
Long-term protein intake up to 2 g/kg per day is considered safe for healthy adults with normal kidney function. For a 140-pound woman, that’s about 127 grams. The tolerable upper limit for well-adapted individuals is 3.5 g/kg per day, but chronic intake above 2 g/kg has been linked to digestive and kidney strain and is generally not recommended. Most women aiming for better health, fitness, or weight management will land comfortably in the 1.2 to 1.6 g/kg range, well within safe bounds.