Most adult women need between 46 and 105 grams of protein per day, depending on body weight, activity level, and life stage. The old baseline of 46 grams per day, which has been the standard recommendation for decades, is now widely considered a minimum rather than a target. The 2025-2030 Dietary Guidelines for Americans raised the suggested range to 1.2 to 1.6 grams per kilogram of body weight per day, which is 50 to 100 percent higher than the previous minimum.
The Old Recommendation vs. the New One
For years, the Recommended Dietary Allowance (RDA) for protein for all adult women, regardless of age, was a flat 46 grams per day. That number was designed to prevent deficiency in a sedentary person, not to promote optimal health. It translates to roughly 0.8 grams per kilogram of body weight, which for a 140-pound (64 kg) woman works out to about 51 grams.
The updated dietary guidelines now suggest 1.2 to 1.6 grams per kilogram per day. For that same 140-pound woman, the new range is approximately 77 to 102 grams daily. For a 160-pound (73 kg) woman, it’s about 88 to 117 grams. This shift reflects growing evidence that higher protein intake supports muscle maintenance, bone health, and metabolic function across the lifespan.
How to Calculate Your Personal Target
The simplest approach is to convert your weight to kilograms (divide pounds by 2.2) and then multiply by a factor based on your activity level and goals:
- Sedentary adults: 1.2 g/kg per day (the new lower end)
- Regularly active or exercising: 1.2 to 1.5 g/kg per day
- Strength training or intense exercise: 1.6 g/kg per day or slightly above
- Losing weight: 1.2 to 1.6 g/kg per day, based on your goal weight rather than your current weight
A 150-pound woman who exercises a few times a week would divide 150 by 2.2 to get 68 kg, then multiply by 1.2 to 1.5. Her target range: roughly 82 to 102 grams of protein per day.
Why Higher Protein Helps With Weight Loss
When you eat fewer calories to lose weight, your body doesn’t just burn fat. It also breaks down muscle. A 12-week study of women on a calorie-restricted diet found that those who got 30 percent of their calories from protein lost significantly less muscle than those who got 18 percent. The higher-protein group lost an average of 1.5 kg of lean body mass compared to 2.8 kg in the lower-protein group, even though total weight loss was similar.
The higher-protein group also reported feeling more satisfied and experiencing more pleasure from eating during the diet. That’s a practical advantage: if you feel less deprived, you’re more likely to stick with a calorie deficit long enough to see results. Importantly, the study found no meaningful negative effects on kidney function or blood lipids from the higher protein intake.
Protein Needs During Pregnancy
Protein requirements increase substantially during pregnancy, and the increase isn’t uniform across trimesters. Recent research using more precise measurement methods found that pregnant women need approximately 1.2 grams per kilogram per day during early pregnancy (around 16 weeks) and 1.52 grams per kilogram per day during late pregnancy (around 36 weeks).
In practical terms, the FAO estimates that pregnant women should consume an additional 0.7 grams of protein per day in the first trimester, about 10 extra grams in the second, and roughly 31 extra grams in the third. So a woman who normally aims for 80 grams daily would want to work up to about 111 grams by her final trimester. This makes sense given that the third trimester is when the fetus is growing most rapidly and the body is producing the most new tissue.
After Menopause: Protecting Muscle and Bone
Muscle loss accelerates after menopause due to declining estrogen levels. Women can lose up to 3 to 5 percent of their muscle mass per decade after 30, and that rate increases after menopause. This makes protein intake especially important for women over 50.
Mayo Clinic recommends that postmenopausal women aim for 1.0 to 1.2 grams of protein per kilogram of body weight daily. Women who exercise regularly or are actively trying to lose weight should aim for the higher end of that range. For a 155-pound postmenopausal woman, that works out to roughly 70 to 85 grams per day, well above the old 46-gram minimum.
Protein also plays a direct role in bone strength. Collagen, the most abundant protein in the body, is the main structural protein in bone. Chronically low protein intake increases fracture risk, which is already elevated in postmenopausal women due to declining bone density.
Spreading Protein Across Meals
Your body builds muscle most efficiently when protein is distributed throughout the day rather than loaded into one meal. Research suggests that roughly 0.4 grams per kilogram per meal, spread across at least four eating occasions, optimally stimulates muscle building. For a 140-pound woman, that’s about 25 to 30 grams per meal.
This doesn’t mean protein eaten in larger amounts is wasted. Your body still digests and uses it for energy, immune function, and other processes. But if your primary goal is maintaining or building muscle, consistent protein at each meal matters more than a single large serving. A common pattern that falls short: a low-protein breakfast (toast and fruit, maybe 5 grams), a moderate lunch (15 grams), and a protein-heavy dinner (40 grams). Redistributing that same total more evenly would be more effective.
Signs You’re Not Getting Enough
True protein deficiency is uncommon in developed countries, but chronically low intake is not. The signs can be subtle and easy to attribute to other causes. Hair that breaks easily, feels thinner, or falls out more than usual can signal inadequate protein, since hair is made almost entirely of a protein called keratin. Dry, pale skin is another early sign.
More systemic effects include getting sick more often, since your body needs protein to produce the antibodies that fight infections. You might also notice slow recovery from workouts, persistent fatigue, or unexpected weight gain. That last one is counterintuitive: when you lose muscle from low protein intake, your metabolism slows, making it easier to gain fat. Feeling unusually hungry between meals, especially craving carbs and snacks, can also point to meals that are too low in protein.
In more severe cases, low protein leads to edema (visible swelling in the hands and legs), anemia, and significant muscle wasting. These are rare but worth knowing about, particularly for women with eating disorders or those following very restrictive diets.
Putting It Into Practice
Hitting a daily protein target of 80 to 100 grams is more achievable than it sounds once you learn which foods deliver. A palm-sized portion of chicken, fish, or lean meat provides roughly 25 to 30 grams. A cup of Greek yogurt has about 15 to 20 grams. Two eggs provide 12 grams. A cup of cooked lentils has around 18 grams. Even a glass of milk adds 8 grams.
If you’re vegetarian or vegan, combining legumes, tofu, tempeh, seeds, and whole grains throughout the day easily reaches these targets. A tofu stir-fry with edamame and quinoa can deliver 35 or more grams in a single meal. The key is planning ahead so that every meal and snack includes a meaningful protein source rather than relying on one large serving at dinner to make up the difference.