Why you can’t stop at just one potato chip

Researchers have discovered the secret of potato chips - why it is that once you pop, you can’t stop - and have even come up with a complicated-sounding name for the phenomenon: hedonic hyperphagia.

“That’s the scientific term for ‘eating to excess for pleasure, rather than hunger’,” said Tobias Hoch, who conducted a study into the condition.

“It’s recreational overeating that may occur in almost everyone at some time in life. And the chronic form is a key factor in the epidemic of overweight and obesity that here in the United States threatens health problems for two out of every three people.”

Hoch presented his findings at the 245th National Meeting & Exposition of the American Chemical Society, the world’s largest scientific society.

Hoch’s team at FAU Erlangen-Nuremberg, in Erlangen, Germany, explored the condition in a study in which one group of laboratory rats was fed potato chips. Another group was fed, as Hoch puts it, “bland old rat chow”. The researchers then used MRI devices to analyse the rats’ brains, comparing differences in activity between the ‘rats-on-chips’ and ‘rats-on-chow’.

The rat chow contained the same ratio of fat and carbohydrates as the potato chips, but the rats’ brains reacted much more positively to the chips.

“The effect of potato chips on brain activity, as well as feeding behaviour, can only partially be explained by its fat and carbohydrate content,” explained Hoch. “There must be something else in the chips that makes them so desirable.”

When offered one of three test foods - powdered rat chow, a mixture of fat and carbs, or potato chips - the rats more actively pursued the potato chips. What’s more, the rats were most active after eating the chips. Hoch puts this down to the chips’ high energy content.

Mapping the rats’ brains with manganese-enhanced magnetic resonance imaging (MEMRI), the researchers found that the reward and addiction centres in the brain recorded the most activity. But the food intake, sleep, activity and motion areas also were stimulated significantly differently by eating the potato chips.

“By contrast, significant differences in the brain activity comparing the standard chow and the fat carbohydrate group only appeared to a minor degree and matched only partly with the significant differences in the brain activities of the standard chow and potato chips group,” Hoch said.

If scientists can pinpoint the molecular triggers in snacks that stimulate the reward centre in the brain, Hoch says it may be possible to develop drugs or nutrients that can be added to foods to block this attraction to snacks and sweets. The next project for Hoch’s team is to identify these triggers.

Unfortunately, Hoch says these findings are unlikely to work the other way. He says there’s no evidence that ingredients could be added to healthy, but unpopular, foods like Brussels sprouts to affect the rewards centre of the brain so we crave healthy foods.