If you're planning to have children and want to help them avoid gaining weight... researchers say lose your own weight before you get pregnant.

Researchers at the Baylor College of Medicine found obesity during pregnancy can cause lifelong obesity in the next generations.

Recent animal studies on how obesity is inherited have suggested that it's not simply genetic... it's somehow triggered in the womb.

Now a study in mice shows mom's obesity during pregnancy not only triggers obesity in her offspring... but also amplifies it.

"They actually were fatter than their mothers. So we saw a population shift in the distribution of body weight, we saw a shift in this distribution toward a heavier and heavier body weight with each generation." Nutrition researcher Rob Waterland and his team at Baylor College of Medicine found this increase by following three generations of a strain of obesity-prone mice.

Since the mice are all genetically identical... getting fat can't be due to changes in the d-n-a code. instead, mom's fat must affect fetal development... boosting babies' body weight for a lifetime. "So this was a non-genetic transmission of obesity across generations."

As they wrote in the "International Journal of Obesity," the finding could help explain the obesity epidemic in people.

But the good news was they also showed that feeding the obese moms special dietary supplements can reverse the effect. "It was able to completely eliminate the obesogenic effect or the obesity- promoting effect of maternal obesity on the offspring."

One of those supplements was folic acid... which pregnant women are already advised to take.

But the researchers stress they do not know if these effects translate from mice to people.

For now, their work supports recommendations that women aim for a healthy weight before pregnancy.

the researchers hope continued work will lead to supplements or diets that would do the same for people.