How much protein do women need?

Most healthy women need at least 0.8 g of protein per kilogram of body weight a day, the official recommended amount in the US and Canada, and more if they're active. Sports nutrition experts recommend 1.4 to 2.0 g/kg for people who exercise, with about 1.6 g/kg a good target if you lift weights, and a European expert group recommends 1.0 to 1.2 g/kg after menopause. For a 65 kg (143 lb) woman, that's about 52 g a day at the low end and about 104 g if she lifts.

How to work out your number

Find the row that fits you best, then multiply the number by your weight in kilograms. To get kilograms, divide your weight in pounds by 2.2. If two rows fit, such as lifting weights after menopause, go with the higher one.

These are ranges for healthy adults, not a personal prescription. The rest of this article explains where each number comes from and how solid it is.

What each number means

Mostly sitting: 0.8 g/kg

The RDA for adult women is 0.8 g/kg a day at every age, from 19 to over 70. The US and Canadian tables turn that into 46 g a day by multiplying it by a reference body weight, so your own number will be different if you weigh more or less. It's the starting point for healthy adults. The sports nutrition groups below recommend more once you train, and the European group recommends more after menopause.

Regularly active: 1.4 to 2.0 g/kg

The ISSN's 2017 position stand on protein and exercise says 1.4 to 2.0 g/kg a day is enough for most people who exercise to build muscle or keep the muscle they have. If your activity is mostly walking or a couple of light classes a week, our reading is that the lower end is plenty to start with.

Lifting weights: about 1.6 g/kg

A 2018 meta-analysis in the British Journal of Sports Medicine pooled 49 trials with 1,863 participants who did resistance training for at least six weeks. Adding protein increased gains in strength and muscle, and past a total intake of about 1.6 g/kg a day, more protein didn't add any further muscle on average.

Two things to keep in mind. First, 1.6 g/kg is an average across studies, not a hard ceiling, so some people may do a little better with more. Second, every trial in that analysis paired protein with lifting, so the number tells you how much protein supports training, not how much builds muscle on its own.

Lifting while eating in a calorie deficit: start near 2.0 g/kg

When you eat less to lose fat, protein helps you keep muscle. The ISSN says intakes of 2.3 to 3.1 g/kg may be needed to hold on to the most lean mass in resistance-trained people during periods of eating less. That figure is the top of the evidence and comes from people who already lift. A practical starting point, in our view, is the top of the regular range, around 2.0 g/kg, while you keep lifting. Protein can't make up for eating too little overall.

50+ and after menopause: 1.0 to 1.2 g/kg

In 2014, a European expert group, the ESCEO, published a consensus statement on protein and vitamin D for postmenopausal women. It notes that from age 50, women face a higher risk of losing muscle (sarcopenia) and bone (osteoporosis), and that both raise the risk of falls and fractures. Its recommendations:

• About 1.0 to 1.2 g of protein per kg of body weight a day.
• At least 20 to 25 g of high-quality protein at each main meal.
• Exercise 3 to 5 times a week, with protein eaten close to your sessions.

The ISSN's 2023 position stand on female athletes goes further for women who train: it advises peri- and postmenopausal women to aim for the upper end of its range, roughly 1.8 to 2.2 g/kg. The two groups wrote for different people, so the numbers don't match. If you're over 50 and lifting, the lifting row is the better fit, in our view. Our menopause workout plan covers the training side.

Pregnant or breastfeeding: talk to your clinician

The official tables raise the RDA to 1.1 g/kg a day in the second half of pregnancy and 1.3 g/kg while breastfeeding. In the first half of pregnancy, the requirement is the same as before. Your own needs depend on your health, your appetite and whether you exercise, so ask your clinician or a registered dietitian for a number that fits you before changing how much you eat.

Does protein need change across your cycle?

Possibly a little, but nobody has measured it directly. The ISSN's 2023 position stand suggests naturally cycling athletes consider about 12% more protein in the luteal phase, the one to two weeks before a period, because progesterone seems to increase protein breakdown. The same position stand also says no studies have looked specifically at female athletes' protein needs across the menstrual cycle.

In practice:

• Keep your daily target the same all month.
• If you train hard, adding a little in the luteal weeks is low risk. For a 1.6 g/kg target, 12% more is about 1.8 g/kg.
• Don't expect it to change your results much on its own.

Our cycle syncing meal plan covers protein, iron and appetite in each phase, and our review of the cycle syncing research includes a lab study that compared muscle building in two phases.

How to spread it over the day

How you split your protein matters less than the daily total, but a few guidelines help:

• Aim for 20 to 40 g per meal. The ISSN suggests about 0.25 g/kg, or 20 to 40 g, per meal, spaced every 3 to 4 hours. After menopause, the ESCEO suggests at least 20 to 25 g at each main meal.
• Fill the gaps you have. A light breakfast is a common gap and usually the easiest one to fill.
• Don't rush after training. The ISSN notes that protein before or after a session both help, and the best timing is largely a matter of what suits you.

For example, a 65 kg woman who lifts and aims for 1.6 g/kg needs about 104 g a day. That's four meals of about 26 g, or three meals of 30 to 35 g plus a snack.

When you're ready to turn your number into actual food, our high protein meal plan for women has portion sizes, a sample day and vegetarian and vegan swaps.

Is eating more protein safe?

For healthy adults, the research is reassuring.

• Kidneys: A 2018 meta-analysis in The Journal of Nutrition pooled 28 trials with 1,358 adults without kidney disease. Diets with at least 1.5 g/kg, at least 20% of calories from protein or at least 100 g a day didn't change kidney function any differently from normal or lower-protein diets.
• Upper limit: The US and Canadian tables set no upper limit for protein. Health Canada notes that the lack of a limit doesn't mean people can tolerate very high intakes long term.
• Healthy range: The same tables put the healthy range at 10 to 35% of your daily calories from protein.

More than you need isn't harmful for most healthy people, but it isn't more helpful either. Past about 1.6 g/kg, extra protein didn't add muscle on average, and a very high protein diet can leave less room for fiber-rich carbohydrates, fruit and vegetables.

If you have kidney disease or reduced kidney function, the kidney research above doesn't apply to you. Talk to your doctor before raising your protein.

What to do this week

• Pick your row in the table and multiply by your weight in kilograms. Round it to a simple number.
• Log three typical days of eating, including one weekend day, and add up the protein. Most food labels and tracking apps list it.
• Compare meals, not just the total. Look for any meal under about 20 g.
• Fix one meal at a time, starting with breakfast if it's light.
• Recheck your number when things change: you start lifting, begin a diet, reach menopause or get pregnant.

If you'd rather not do the math, HerShape sets a daily protein target from your body weight and builds your meals and workouts around it.

What to watch for

Talk to a doctor or registered dietitian before changing your protein if:

• You have kidney disease, diabetes or another long-term condition.
• You're pregnant, trying to get pregnant or breastfeeding.
• You have a history of disordered eating. Tracking grams may not be helpful for you, and a dietitian can help you plan with portions instead.
• Your periods become irregular or stop while you're training more or eating less. The ISSN's 2023 position stand calls eating enough overall the first nutrition priority for women who train, and more protein can't make up for too little food.
• You're over 50 and losing strength, losing weight without trying or having falls.

The bottom line

Most women need at least 0.8 g of protein per kg of body weight a day, and more once they're active: 1.4 to 2.0 g/kg if you exercise regularly, about 1.6 g/kg if you lift, toward 2.0 if you're lifting while eating less, and 1.0 to 1.2 g/kg after menopause. The lifting numbers rest on the most trials, the life-stage advice comes mostly from expert consensus, and there's no direct research yet on changes across the cycle. Pick your number, split it over three or four meals, and check in with a clinician if you're pregnant or have a health condition.

Related guides

• High protein meal plan for women: food portions, a 120 g sample day, vegetarian and vegan swaps and a shopping list
• Cycle syncing meal plan: protein, iron and a sample day for each phase of your cycle

Sources

• Health Canada: Dietary reference intakes tables: Reference values for macronutrients
• Journal of the International Society of Sports Nutrition (2017): International Society of Sports Nutrition Position Stand: protein and exercise
• British Journal of Sports Medicine (2018): 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
• Maturitas (2014): The role of dietary protein and vitamin D in maintaining musculoskeletal health in postmenopausal women: a consensus statement from the ESCEO
• Journal of the International Society of Sports Nutrition (2023): International society of sports nutrition position stand: nutritional concerns of the female athlete
• The Journal of Nutrition (2018): Changes in Kidney Function Do Not Differ between Healthy Adults Consuming Higher- Compared with Lower- or Normal-Protein Diets: A Systematic Review and Meta-Analysis