Battle of the Sexes: Men vs Women Nutrient Needs

From calories to calcium, women and men have distinctly different needs when it comes to nutrition. Some of it has to do with size. And some of it has to do with function; childbearing puts different requirements on the female body. Teasing out these male-female nutrition nuances continues to keep scientists hopping as they try to figure out why everything from alcohol to iron impacts health between the sexes so differently.

It all starts out being equal, but around age 10 puberty delivers a whopping blast of testosterone to boys, bulking up their muscle mass. In the realm of "life isn't fair" scenarios, this larger muscle mass ratchets up calorie requirements. By adulthood men have up to 20% more muscle than women, widening the calorie gap.

He needs:  An average 175-pound (moderately active) man needs 2800 calories.

She needs:  An average 125-pound (moderately active) woman needs 2000 calories.

Hogging the spotlight for the role it plays in preventing birth defects, female needs for this B-vitamin edge out male needs during childbearing. Still, both sexes need folate to continually form new hair, skin, and other cells. It's also a potential protector against colon cancer.

He needs:  400 mcg per day

She needs:  400 mcg per day in childbearing years, particularly in the month before conception; 600 mcg during pregnancy

Experts target advice about eating plenty of dairy and calcium-rich foods to women mainly because females are four times as likely to develop the bone crippling disease osteoporosis. In the years after menopause, women can lose 20 percent of bone mass. Men lose bone too, but excess dairy may hike risk for prostate cancer.

He needs: 800 mg

She needs:  1000 mg ages 19-50; 1200 mg after 50

Vital for keeping immune systems in top order and good for energy, iron requirements are dramatically different early in life for women due to monthly blood loss. Iron from vegetable sources (dried beans, legumes) isn't absorbed as well as the iron in meats, but both are valuable. In fact, adding vitamin C rich foods like citrus and tomatoes easily boosts iron absorption from vegetable foods.

He needs:  8 mg

She needs:  18 mg per day during child bearing years (27 mg if pregnant); 8 mg per day after 51

For women and men, foods rich in monounsaturated fats like olive oil, avocado, and nuts are great for the heart and may even flatten bellies. Unsaturated fats in fish (omega 3 fatty acids) are heart healthy too. But preliminary studies suggest that flaxseed, canola oil, and foods rich in plant-based omega 3 fats, also called alpha-linolenic acids (ALA), may raise the risk of prostate cancer in men.

He needs:  30-35% of daily calories; 2/3 of it unsaturated

She needs: 30-35% of daily calories; 2/3 of it unsaturated

While the Institute of Medicine recommends anywhere from 10-35 percent of calories come from protein, Harvard researchers suggest about a third a gram of protein per pound of body weight. There's no need to be exact though, which is why Harvard sets the protein bar the same for both sexes. Main goal: focus on lean proteins like chicken, fish, and legumes.

He needs:  60 g per day

She needs:  60 g per day

A few beers with the buddies will have little impact on a man's health if he's drinking responsibly. It may even reduce risk for heart attack. But for women, benefits are a mixed bag, something to consider carefully. Studies suggest imbibing in a glass of wine might be healthy, but even these tiny doses of alcohol can increase breast cancer risk.

He drinks:  2 drinks per day (12 oz beer; 5 oz wine, 1.5 oz 80-proof spirits)

She drinks:  1 drink per day

In the final analysis, nutritional differences between men and women turn out to be subtle ones. Most of the variance is really a size thing; women are smaller and less muscular so require fewer calories. Yes, women may need a little more calcium, a little more iron, and a little less alcohol, but general consensus is that both sexes benefit from the same healthy diet strategies—plenty of whole grains, healthy fats, lots of fruits and vegetables, and lean sources of dairy and protein.