Most women need between 46 and 75 grams of protein per day, but the real answer depends on your body weight, activity level, and life stage. The baseline recommendation is 0.8 grams of protein per kilogram of body weight, which works out to about 0.36 grams per pound. For a 140-pound woman, that’s roughly 50 grams daily. But that number is a minimum to prevent deficiency, not necessarily the amount for optimal health, and many women benefit from eating significantly more.
The Baseline for Healthy Adults
The Recommended Dietary Allowance of 0.8 grams per kilogram of body weight applies to sedentary, generally healthy adult women. Here’s what that looks like at different body weights:
- 120 pounds (54 kg): about 44 grams per day
- 140 pounds (64 kg): about 51 grams per day
- 160 pounds (73 kg): about 58 grams per day
- 180 pounds (82 kg): about 65 grams per day
These numbers are enough to meet basic metabolic needs, but they were set to prevent deficiency in the general population. If you exercise regularly, are trying to lose weight, or are over 50, your target is higher.
Protein for Active Women
Women who exercise regularly need substantially more protein than the baseline. Current sports nutrition research recommends 1.4 to 1.6 grams per kilogram of body weight per day for active women. During periods of heavy training or calorie restriction, that number can go up to 2.2 grams per kilogram. For a 140-pound woman, that range translates to roughly 90 to 140 grams daily.
Endurance athletes have their own considerations. Running, cycling, and other sustained cardio increase the rate at which your body breaks down amino acids for fuel. Research suggests female endurance athletes should target about 1.89 grams per kilogram on training days, which is actually beyond the upper end of most general athletic guidelines. For a 140-pound woman, that’s about 120 grams.
Resistance training is the single most effective stimulus for building and maintaining muscle. Pairing it with protein intakes of 1.4 to 1.6 grams per kilogram forms what researchers describe as the cornerstone of muscle health, performance, and long-term well-being for women.
Protein for Weight Loss
When you’re eating fewer calories than you burn, your body doesn’t just pull from fat stores. It also breaks down muscle tissue, which is something higher protein intake can help slow down. Research from Washington University School of Medicine compared women eating the standard 0.8 grams per kilogram during weight loss to women eating 1.2 grams per kilogram. The higher-protein group preserved slightly more lean tissue, though the difference was modest (about a pound). The more noticeable benefit of extra protein during a calorie deficit is hunger control. Protein is the most satiating macronutrient, meaning it keeps you feeling full longer between meals.
If you’re actively losing weight, aiming for at least 1.2 grams per kilogram is a reasonable starting point. Women who are also strength training during a cut may benefit from going higher, into the 1.4 to 1.6 range.
Protein After Menopause
Menopause accelerates muscle loss. Declining estrogen levels reduce the body’s ability to build and repair muscle tissue, making adequate protein even more important. Mayo Clinic recommends post-menopausal women aim for 1.0 to 1.2 grams of protein per kilogram of body weight daily. The higher end of that range is appropriate if you exercise regularly, are older, or are managing your weight.
For a 150-pound post-menopausal woman, this means roughly 68 to 82 grams per day, a noticeable step up from the 54 grams the standard RDA would suggest. Combined with resistance training, this level of protein supports muscle, bone, and metabolic health over the long term.
Protein During Pregnancy
Pregnant women should aim for a minimum of 60 grams of protein per day, which accounts for roughly 20 to 25 percent of total calorie intake. This supports fetal growth, placental development, and the significant increase in blood volume that happens during pregnancy. Many women will need more than 60 grams depending on their pre-pregnancy weight and activity level, so think of that number as a floor rather than a target.
How to Spread Protein Across the Day
Your body builds muscle most efficiently when protein is distributed evenly across meals rather than loaded into one or two sittings. Research shows that muscle protein synthesis is about 25 percent greater when protein is spread across breakfast, lunch, and dinner compared to the common pattern of eating very little protein at breakfast and most of it at dinner.
A useful per-meal target is about 0.31 grams of protein per kilogram of body weight. For a 140-pound woman, that’s roughly 20 grams at each meal. You need about 3 grams of leucine (an amino acid concentrated in animal proteins, dairy, and soy) to flip the switch from muscle breakdown to muscle repair, and that amount is found in roughly 30 grams of high-quality protein. This doesn’t mean protein beyond 30 grams per meal is wasted. When you eat whole foods that digest slowly, like meat, eggs, beans, and dairy, your body continues absorbing and using protein well beyond that threshold.
Plant-Based vs. Animal Protein
Animal proteins contain higher amounts of essential amino acids, particularly leucine and lysine, and are more digestible than most plant sources. This doesn’t mean plant-based diets are inadequate, but it does mean plant-based eaters should be more intentional. Eating a variety of plant protein sources (legumes, grains, nuts, seeds, soy) throughout the day covers the full spectrum of essential amino acids. If you eat exclusively plant-based, aiming for the higher end of whatever protein range applies to your situation is a smart hedge against lower digestibility.
Upper Limits and Safety
For most healthy women who aren’t elite athletes, keeping protein intake at or below 2 grams per kilogram of ideal body weight is a reasonable ceiling. For a 140-pound woman, that’s about 125 grams per day. Very high protein diets are associated with an increased risk of kidney stones, and diets heavy in red and processed meat may raise the risk of heart disease and colon cancer. However, those risks are tied more to the protein source than to protein itself. High-protein diets built around poultry, fish, dairy, legumes, and other plant sources don’t appear to carry the same risks. Women with existing kidney disease should be especially cautious with high protein intakes.