Men and women need the same amount of protein per kilogram of body weight. The official recommendation for all adults is 0.8 grams of protein per kilogram of body weight per day, and that number doesn’t change based on sex. But because men typically weigh more and carry more muscle mass, their total daily protein intake in grams ends up being higher. So the short answer is: men need more protein in absolute terms, but not because their bodies process protein differently.
Why the Recommendation Is the Same
The Recommended Dietary Allowance for protein, set at 0.8 g/kg/day, has been essentially unchanged for over 70 years. It does not distinguish between men and women. This is because, at a cellular level, male and female muscle tissue handles protein in remarkably similar ways.
A large body of nitrogen balance research supports this. Nitrogen balance is the standard method for measuring whether someone is getting enough protein: when you eat adequate protein, the nitrogen coming in matches what’s going out. A recent systematic review and meta-analysis found no significant difference in nitrogen requirements between males and females. The measured requirement was 109.1 mg nitrogen/kg/day for men and 102.4 mg/kg/day for women, a gap that was not statistically meaningful.
Studies on muscle protein synthesis tell a similar story. When researchers measure how fast muscle tissue builds and breaks down protein, men show higher rates overall. But that difference disappears when the results are adjusted for muscle mass. In other words, a kilogram of muscle in a woman synthesizes protein at the same rate as a kilogram of muscle in a man. The apparent gap comes from men simply having more muscle to maintain.
Where the Real Difference Comes From
The average adult man in the United States weighs roughly 90 kg (about 200 pounds), while the average adult woman weighs around 77 kg (about 170 pounds). Men also carry a higher percentage of lean body mass and a lower percentage of body fat. When you multiply 0.8 g/kg by a larger body with more muscle, you get a bigger number.
National dietary surveys confirm this plays out in real life. USDA data from 2017 to 2020 shows that adult men in the U.S. consume an average of 93.9 grams of protein per day, while adult women average 68.7 grams. Both groups comfortably exceed the minimum RDA, and the roughly 25-gram gap tracks closely with the difference in body size.
Hormones Play a Supporting Role
Testosterone is often cited as the reason men “need more protein,” but its role is more nuanced. Testosterone binds to receptors in muscle cells and activates signaling pathways that promote protein building, gene expression related to muscle structure, and the local production of growth factors. This is why men build and maintain more muscle mass in the first place, which in turn drives higher total protein needs.
Estrogen also supports muscle protein metabolism. It helps regulate skeletal muscle regrowth after periods of disuse, activates some of the same growth-signaling pathways as testosterone, and appears to be critical for maintaining muscle in women. The hormonal environment differs between men and women, but neither hormone makes one sex inherently less efficient at using dietary protein. Throughout most of adult life, men and women of similar health status and body composition display fairly similar protein turnover rates.
Exercise Changes the Equation for Everyone
If you’re physically active, the 0.8 g/kg baseline doesn’t apply to you. The International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg/day for people who exercise regularly. For endurance training, the range is 1.0 to 1.6 g/kg/day. For strength and power training, it’s 1.6 to 2.0 g/kg/day. These recommendations apply equally to men and women.
A 70-kg woman doing regular strength training would aim for 112 to 140 grams of protein per day. A 90-kg man doing the same training would aim for 144 to 180 grams. The per-kilogram target is identical. The total is different because body size is different. During weight loss specifically, higher protein intake helps preserve lean muscle mass, and some evidence suggests this benefit may be particularly pronounced in men, likely because they have more muscle mass at risk of being lost during calorie restriction.
Pregnancy and Breastfeeding Raise the Bar
One period of life where women’s protein needs per kilogram genuinely surpass the standard recommendation is during pregnancy and breastfeeding. Late-stage pregnancy appears to require around 1.52 g/kg/day, nearly double the standard RDA. Preliminary research on exclusively breastfeeding women suggests needs may be even higher, in the range of 1.7 to 1.9 g/kg/day. These figures rival or exceed the protein recommendations for competitive athletes, reflecting the enormous biological demand of growing and feeding a new human.
How to Think About Your Own Needs
Rather than comparing your needs to the opposite sex, the most useful approach is to calculate your own target based on body weight and activity level. For a sedentary adult, 0.8 g/kg/day is the floor. Many nutrition researchers now consider this a minimum to prevent deficiency rather than an optimal intake, noting that the Acceptable Macronutrient Distribution Range for protein goes as high as 3.67 g/kg/day and that practical recommendations like the USDA’s MyPlate suggest 1.48 to 1.86 g/kg/day.
If you exercise regularly, aim for at least 1.4 g/kg/day. If your goal is building or preserving muscle, move toward 1.6 to 2.0 g/kg/day. These numbers work regardless of sex. Multiply by your weight in kilograms, and you have your daily target in grams. A 68-kg (150-pound) person doing moderate exercise would target roughly 95 to 136 grams per day, whether they’re a man or a woman.