A: On average newborn boys are slightly heavier than newborn girls. Researchers are interested in knowing if their heavier birth weight results from their mothers eating more during pregnancy or whether mothers of boys are more efficient at utilizing the food they eat.

In 2003 the British Medical Journal published results of a study on 244 American women who filled out a diet questionnaire during their second trimester. The analysis showed that compared to mothers of girls, women carrying male fetuses had a 10% higher energy intake (including protein, carbohydrates and fat), suggesting that these women had higher nutritional requirements. Surprisingly, these same women did not gain more weight than other women in the study, although birth weight usually correlates with mother’s weight gain.

In contrast, another survey involving 300 British pregnant women showed similar energy intake between pregnant women carrying male and female babies. In this study, the only difference found was that women carrying girls consumed 5% more fat and calories during the first trimester of pregnancy.

Based on these two studies it’s premature to recommend that you consume more calories because you’re carrying a boy. As long as you provide yourself with a healthy, balanced diet containing ample calories and nutrients, you will be supplying your baby what he needs to grow. For more specifics, see my article titled, “Nutrition During Pregnancy” on this web site.