Pregnant mothers who consume junk food actually cause changes in the development of the opioid signalling pathway in the brains of their unborn children.
This change results in the babies being less sensitive to opioids, which are released upon consumption of foods that are high in fat and sugar.
In turn, these children, born with a higher "tolerance" to junk food need to eat more of it to achieve a "feel good" response, the study published in FASEB journal reported. "The results of this research will ultimately allow us to better inform pregnant women about the lasting effect their diet has on the development of their child's lifelong good preferences and risk of metabolic disease," said Beverly Muhlhausler, a researcher involved in the work from the FOODplus Research Centre at the School of Agriculture Food and Wine at The University of Adelaide in Adelaide, Australia.
"Hopefully, this will encourage mothers to make healthier diet choices which will lead to healthier children," Muhlhausler said.
Muhlausler and colleagues studied the pups of two groups of rats, one of which had been fed a normal rat food and the other which had been fed a range of human "junk foods" during pregnancy and lactation.
After weaning, the pups were given daily injections of an opioid receptor blocker, which blocks opioid signalling.
Blocking opioid signalling lowers the intake of fat and sugar by preventing the release of dopamine.
Results showed that the opioid receptor blocker was less effective at reducing fat and sugar intake in the pups of the junk food fed mothers, suggesting that the opioid signaling pathway in these offspring is less sensitive than for pups whose mothers are eating a standard rat feed.