News You Can Use: No Need to Eat for Two When Pregnant

By Dawn Van Osdell

Researchers at Imperial College London have proven that there’s no need for pregnant women to “eat for two,” because their bodies adapt to absorb more energy from the same amount of food they would normally consume. Thanks to a hormone secreted during pregnancy—even as early as fertilization—a mother-to-be’s digestive system dramatically grows, stimulating her body to store more fat to support the demands of a growing fetus.

“We normally think of our internal organs as being a fixed size, but the fact is that they are not. They can grow and change, and we show that this is important for making babies,” says Irene Miguel-Aliaga, the lead researcher in the study conducted at the Medical Research Council's Clinical Sciences Centre in London.

Until now, scientists had thought that a pregnant woman’s appetite increased as her baby's demand for energy increased. This new research—performed in fruit flies, which have genes that are also present in humans—is the first to show that a “juvenile hormone” triggers the changes to the intestine and fat metabolism, similar to the way human thyroid hormones regulate energy demands. “Studies in fruit flies have been very valuable in providing insights into human physiology,” say Joe McNamara, M.D. and author of the study. “This research points to a new scientific explanation why eating for two during pregnancy is not necessary, and may even be harmful, as a growing body of evidence indicates that a mother’s diet can impact a child’s propensity to be obese in later life. “

The research also sheds some light on why some women may have trouble losing weight after pregnancy. If hormone levels fail return to normal after birth, a mother’s intestine may remain abnormally large, so she will continue to extract extra energy from her food.  

Eating for two may be an old wives’ tale some pregnant women will be sad to see go. But in the long run, we and our growing families will be healthier and happier having forgone that third trimester cupcake binge!

Photograph courtesy of UrbanSitter