Overindulging in high-calorie, sugary, fatty and salty treats during pregnancy and lactation might produce a child with a fondness for junk food, the results of an animal study suggest.

British scientists found that pregnant or lactating rats that ate a diet full of junk-food favorites - like doughnuts, chocolate and potato chips - gave birth to pups with a penchant for overeating the same types of foods.

The offspring were not, however, prone to overeating their normal, well-balanced animal chow.

The findings, say researchers, suggest that too much junk food during pregnancy and breastfeeding may affect early development of taste preferences and appetite control.

Appetite control is complex, and involves a system of hormones that work with a brain region called the hypothalamus - the main regulator of hunger and feelings of fullness.

Food also stimulates the “reward centers” of the brain, which makes eating pleasurable and therefore can encourage overindulgence, explained Dr. Stephanie A. Bayol, the lead author of the new study and a researcher at the Royal Veterinary College in London.

In particular, she told Reuters Health, fat, sugar and salt - staples of junk food - are known to stimulate the brain’s reward centers.

“In our study,” Bayol explained, “we think that eating large amounts of junk food rich in fat, sugar and salt in pregnancy and breastfeeding may influence the way the appetite centers develop in the brain of the offspring, leading to a greater preference for junk food.”

She and her colleagues report the findings in the British Journal of Nutrition.

The study involved two groups of female rats that were given either normal chow alone or chow plus junk food during pregnancy and lactation. When the pups were ready to be weaned, they were given either chow or chow plus junk food.

The researchers found that pups whose mothers had eaten junk food tended to overeat those foods themselves. However, if the offspring were given only standard chow, they did not overeat.

How well these findings might translate to humans is unclear, according to Bayol. But she said they support advice that pregnant women, and everyone else, should be following anyway: eat a well-balanced diet rich in nutritious, low-calorie foods like fruits, vegetables and whole grains.

“Our study is just reinforcing that message and emphasizes that eating a balanced diet is particularly important for pregnant and breastfeeding women,” Bayol said.

That’s not to say women should feel guilty about the occasional dessert, she noted; they just shouldn’t take the old saying about “eating for two” to heart.

SOURCE: British Journal of Nutrition, August 14, 2007.