Once You Pop, You Can't Stop: Scientists Explain Why Junk Food is So Addictive
"Once you pop, you can't stop." It's not just a slogan for Pringle's; it's a truism for anyone who has thought that they would have just one chip, only to down the entire bag. That attraction to junk food like chips and chocolate has real consequences - two-thirds of Americans are overweight and obese, in part because of the attraction to these foods. A recent study conducted by researchers from FAU Erlangen-Nuremberg found out exactly what happens to the brain when it becomes impossible not to continue eating.
The phenomenon is called "hedonic hyperphagia", and it occurs in hundreds of millions of people around the world. "That's the scientific term for 'eating to excess for pleasure, rather than hunger,'" study author Tobias Hoch said in a statement. "It's recreational over-eating 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."
The researchers performed a study on rats. The rats were offered one of three types of food: standard rat chow, potato chips and a mixture of carbohydrates and fat. This last food, though perhaps seemingly an odd choice, was added to the mix because researchers believed that part of the reason that people like potato chips and chocolate so much was that they have a high ratio of fat and carbohydrates which, in turn, sends a pleasing message to the brain.
The rats ate similar amounts of all three types of food. However, they pursued the potato chips most aggressively, even surpassing their level of enthusiasm for the fat and carbohydrate mixture. That means that there is an additional component that makes junk food so appealing. When the researchers scanned the rats' brains, they found that their brains had changed, sparking the most activity in the reward and addiction centers, but also provoking changes in the food intake, sleep, activity and motion areas of the brain.
How do the researchers explain people who seem to be unaffected by junk food? The scientists suggest that it could be as simple as willpower - but it could also be linked to how their brains are wired. "Possibly, the extent to which the brain reward system is activated in different individuals can vary depending on individual taste preferences," Hoch stated. "In some cases maybe the reward signal from the food is not strong enough to overrule the individual taste."
Researchers hope to pinpoint the molecular triggers that are responsible for the addictive nature of potato chips. That way, they can create drugs that can block them. The scientists do not think that there is a way to make other more healthful foods, like Brussel sprouts, have the same effect as chocolate.
The study was presented at the National Meeting and Exposition of the American Chemical Society.