New research suggests that eating a high-fat diet during pregnancy may cause changes in the fetal brain that promote the development of obesity.

Dr Sarah Leibowitz and colleagues at Rockefeller University compared the offspring of rats fed a high-fat diet with those fed a normal diet containing moderate amounts of fat. Results showed that the offspring of rats fed a high-fat diet ate more, weighed more throughout their lives, and began puberty earlier than the offspring of rats fed a normal diet.

Furthermore, the rats born to mothers who ate a high-fat diet also had higher levels of triglycerides and orexigenic, or appetite-promoting, peptides at birth and as adults. Further examination revealed that feeding the mother rats a high-fat diet caused changes in the brain of their fetal offspring which left the unborn rats with a significantly higher than normal number of orexigenic peptide-producing neurons. In comparison, the offspring of rats fed a normal diet had far less of the specialized neurons, and they did not appear until after the rats had been born.

“We've shown that short-term exposure to a high-fat diet in utero produces permanent neurons in the fetal brain that later increase the appetite for fat. This work provides the first evidence for a fetal program that links high levels of fats circulating in the mother's blood during pregnancy to the overeating and increased weight gain of offspring after weaning,” said Dr Leibowitz in a news release. “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. We're programming our children to be fat.”

Chang GQ, Gaysinskaya V, Karatayev O, Leibowitz SF. Maternal High-Fat Diet and Fetal Programming: Increased Proliferation of Hypothalamic Peptide-Producing Neurons That Increase Risk for Overeating and Obesity. The Journal of Neuroscience. 2008;28:12107-12119. doi:10.1523/JNEUROSCI.2642-08.2008

News release: Fatty diet during pregnancy produces new neurons in fetal brain. Rockefeller University. November 10th 2008.