Almost all pregnant women need to get more protein, more of certain vitamins and minerals such as folic acid and iron, and more calories (for energy). But adding calories doesn’t mean “eating for two.” If you start off at a healthy weight, you need no extra calories during the first trimester, about 300 extra calories a day in the second trimester, and about 450 extra calories a day in the third trimester. Many pregnant women give themselves a free pass to eat all of the junk food they crave because of the inaccurate “eating for two” philosophy.
However, new research published in the March 2013 issue of The FASEB Journal suggests that pregnant mothers who consume a lot of junk food actually cause changes to occur in the development of the opioid signaling pathway in the brains of their unborn children. Due to this change, babies are less sensitive to opioids – which are released upon consumption of foods that are high in fat and sugar. In turn, these children – who are born with a higher tolerance to junk food – need to eat more of this type of food to achieve a feel-good response. The research to lay the groundwork for these conclusions was done on rats, which were fed a range of human junk foods during pregnancy and lactation.
“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 food preferences and risk of metabolic disease,” said Beverly Muhlhausler, Ph.D., 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.”
To make this discovery, Muhlhausler and colleagues studied the pups of two groups of rats. One of the groups was fed a normal rat food diet, while the other group was 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 signaling. Blocking opioid signaling 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 ate a standard rat food diet.
“This study shows that addiction to junk food is true addiction,” said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. “Junk food engages the same body chemistry as opium, morphine or heroin. Sad to say, junk food during pregnancy turns the kids into junk food junkies.”
