Rodent of the Week: Too much fat in pregnancy harms babies

Eating too much high-fat food during pregnancy not only makes it harder to lose those postpartum pounds, it can influence a baby's future weight. A study in rats shows that exposure to a high-fat diet during pregnancy produces permanent changes in the offspring's brain that leads to overeating and obesity early in life.

The study is among a growing mountain of evidence that nutrition during pregnancy matters a lot. The researchers from Rockefeller University examined the effects of feeding pregnant rats a high-fat diet for two weeks compared with a balanced diet with a moderate amount of fat. The rats born to mothers who ate the high-fat diet ate more, weighed more throughout life and began puberty sooner than those born to mothers who ate a balanced diet -- even though the high-fat diet was removed at birth. The offspring of the high-fat diet rodents had higher triglycerides at birth, as well.

Perhaps most surprisingly, these baby rats also produced more brain peptides that stimulate eating and weight gain. They had a much higher number of neurons that produce these appetite-stimulating orexigenic peptides and they maintained these neurons throughout life. The offspring of rats who ate the balanced diet had far fewer of these neurons.

"We believe the high levels of triglycerides that the fetuses are exposed to during pregnancy cause the growth of the neurons earlier and much more than is normal," said senior author Sarah F. Leibowitz, director of the Laboratory of Behavioral Neurobiology at Rockefeller.

She says the same mechanism likely occurs in humans. "We're programming our children to be fat."

The study was funded by the National Institutes of Health and is published in this week's issue of Journal of Neuroscience.

-- Shari Roan

Photo credit: Advanced Cell Technology Inc.