For the study, researchers fed one group of mice a normal diet and another group a higher fat diet for eight weeks. Then the mice were mated.
At the end of each mouse's pregnancy the offspring were delivered by c-section and weighed along with their placentas. The researchers then took blood from the mothers and measured the ability of the placenta to transport nutrients to the babies.
They found that female mice fed high fat diets were more likely to have oversized offspring (a risk factor for overweight and obesity) because fat causes the placenta to go into "overdrive" by providing too many nutrients to the foetus.
"Our model may one day lead to dietary recommendations for mothers who are entering pregnancy overweight or obese," said Helen N. Jones, Ph.D., first author of the study.
"We hope this research will ultimately help reduce the number of babies suffering from birth injuries, decrease C-section rates, and lower the risk of babies becoming overweight or obese later in life," she added.
Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, said: "It's no secret that big women tend to have big babies but now we know that there's more at play than genetics. Cutting back on fatty foods during pregnancy might decrease the chance of having a baby that becomes overweight in the future."
This study also suggests that the reverse may be true as wellóhigh fat diets may help prevent undersized babies.
The study is published online in The FASEB Journal.