Protein Needs For Women: How Much Is Enough — And What's Too Much?

The amino acids in protein are essential building blocks for many parts of the female body—from our muscle tissues down to our cells. Protein is consistently being turned over in the body, and it's up to us to replenish it through foods or supplements.

"There's this continual demand for protein, and if that demand isn't met, the body has to go seek it," Chad Kerksick, Ph.D., director of the Exercise and Performance Nutrition Laboratory at Lindenwood University, tells mindbodygreen.

Skeletal muscle is the main reservoir of protein, Kerksick explains, so when we're not getting enough protein, we start to lose muscle tissue. This is something we want to avoid since having adequate muscle is essential for cognitive health1, insulin regulation2, healthy inflammatory markers3, and more.

As for what constitutes "enough" protein, it depends on your body size and composition. The Recommended Dietary Allowance (RDA) of protein is 0.8 gram per kilogram of body weight4 per day. This is the minimum amount of protein a sedentary person needs to meet their nutritional requirements and avoid a nitrogen imbalance, so it's conservative.

The experts interviewed for this article agree that the average moderately active adult will need to consume significantly more protein—somewhere in the range of 1.2 to 2.0 grams per kilogram of body weight, or 0.54 to .90 gram per pound. (More on what this actually looks like in food terms below.)

To fall within the 1.2 to 2.0 grams per kilogram range, a 160-pound woman will want to eat between 87 and 144 grams of protein per day.

If you'd rather not count down to every last gram, leading protein and amino acid requirements researcher Don Layman, Ph.D., previously told mindbodygreen that getting around 100 grams a day is a solid goal for most women. "We find from a metabolic standpoint, working predominantly with women, that if they get below 100 grams per day, they lose most of the benefits of protein: fatty acid metabolism, insulin sensitivity, weight loss, satiety," Layman said on the mindbodygreen podcast.

Breaking up your protein intake throughout the day will give your body a steady supply of those amino-acid building blocks. Consuming around 25 to 30 grams of protein during breakfast, lunch, and dinner, and eating a protein-rich snack or two, will fulfill your daily requirements. "We should strive to get some type of protein feeding every three to four hours or so," says Kerksick. 

Leucine is an essential amino acid that initiates muscle protein synthesis, or the production of new skeletal muscle, when combined with strength training. As Layman's work demonstrates, it takes about 2.5 grams of leucine11 in order to kick-start the muscle-building process for five to six hours. If you don't reach this leucine threshold during each meal, you're leaving some of the key benefits of your protein on the table. Animal proteins tend to have a more favorable leucine composition12 than plant proteins.

As for the role of protein powders and supplements, they can be helpful if you're in a pinch and don't have the time or appetite to eat a complete meal. Just be sure to look for one that has at least 20 to 25 grams of protein per serving and isn't packed with sugars or unnecessary additives.

There is research to show that eating a higher protein diet—at or beyond the 2.0 gram/ kilogram range—can assist with weight loss13, if that's a goal of yours.

"In general, as long as you are cutting your calories, you will lose weight. That's the whole idea of energy balance," says Tang. In caloric deficit, eating a higher proportion of protein can help you lose more fat and less muscle, due to the way protein helps preserve lean mass (when paired with weight training). Protein also tends to be very satiating13, so it can help you become full on fewer calories. See here for a complete guide to using protein to lose fat.

When you eat too much protein (far above that 2.0 gram per kilogram threshold for long periods of time), the excess amino acids are not used as efficiently, and it could cause side effects14 like abdominal discomfort, dehydration, and nausea.

Getting most of your protein from highly processed sources isn't so healthy either. Consume minimally processed and nutrient-rich plant and animal protein sources (ideally ones that are organic/regeneratively grown) to protect your cardiovascular and metabolic health.

Some physicians believe that most women in the developed world already get enough dietary protein and don't need to worry about hitting the 100-gram threshold. They argue that, especially in older adults, a higher intake of animal protein can actually accelerate aging.

This is due to the high amount of the amino acid leucine in animal proteins, which may speed up the aging process due to its effect on mTOR, a signaling system involved in muscle protein synthesis. Indeed, there is some research to show that elevated mTOR levels increase cancer risk15. However, it's important to note that eating a serving of protein causes mTOR to go up and down in a controlled, natural rhythm—it doesn't lead to chronic elevation. So the argument here isn't particularly strong.

There is also solid evidence showing that those with less muscle mass (as estimated by grip strength) tend to age at an accelerated rate, making eating for muscle protein synthesis essential as we get older.

Protein is essential for building and maintaining muscle and regulating key body systems. There's also compelling research to show that consuming more than RDA on protein can help women gain strength, combat inflammation, and avoid insulin resistance. The arguments against a high-protein diet are not applicable to everyone.

For this reason, we believe that most active women will want to consume 1.2 to 2.0 grams of protein per kilogram of body weight.

We're not saying that every woman out there needs to get 100 grams of protein a day: there are certainly exceptions.