If an overweight mother-to-be looses weight prior to becoming pregnant, the baby is likely to be healthier, according to a new study.

Researchers found that babies whose mothers were obese are predisposed to obesity themselves.

The study was done by the University of Texas Center for Pregnancy and Newborn Research at the Health Science Center and the National Institute of Nutrition in Mexico City. The study tested the effects of weight on female rats prior to becoming pregnant.

The rats first received a high fat diet to the point that they became obese. They were then divided into groups. One group diet was changed so that they would lose weight, starting a month prior to becoming pregnant. The other continued on the high-fat diet prior to and during pregnancy, and while nursing.

After the babies were weaned, it was found that triglycerides, insulin, leptin, and insulin resistance were higher in the babies of obese mothers. These babies also had an increase of fat mass and fat cell size.

The babies whose mothers had lost weight prior to becoming pregnant had levels of triglycerides, insulin, leptin, and insulin resistance that were in a normal range. Fat mass and fat cell size were also less in this group.

According to the researchers, this is the first study that shows that weight loss prior to pregnancy can mitigate the negative effects of a mother’s obesity on her future children.

Researchers warned, however, that some health factors, such as heart disease and obesity, which may occur later in life were not accounted for in this study, and said more research needed to be done.