Given the option, most rats will choose sugar instead of cocaine. Their lust for the carbohydrate is so intense that they will go as far as to self-administer electric shocks in their desperation to consume sugar. Rats aren’t alone in this drive. Humans, it seems, do something similar. People who’ve had bariatric surgery sometimes continue to overindulge in highly processed foods, those made from white flour, sugar, butter, and the like, even if it means later enduring vomiting and diarrhea. Daily snacking on processed foods, recent studies show, rewires the brain’s reward circuits. Cravings for tasty meals light up the brain just like cravings for cocaine do, prompting some researchers to ask whether products such as fries or cookies can trigger addiction akin to that associated with drugs or alcohol.
Yet the issue is by no means settled. An ongoing debate persists over whether these foods are truly addictive. Processed foods might provoke compulsive behaviors that reinforce the need to consume more, but do they really have mood-altering effects, another criterion used to define an addiction?
Answers to these questions are complicated by the enormous variety of foods we consume. There is no single opiatelike substance that can be identified as leading someone to become a food addict. Arguments in favor of food addiction suggest that if carbohydrates and fats are mixed together in unnaturally large doses, this creates a rapid “delivery system” for nutrients that results in physiological effects on the brain’s reward system that resemble those produced by cocaine or nicotine.
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Critics of this research suggest that you can’t get addicted to something that’s essential to life. What’s more, while science has pinpointed nicotine in cigarettes and ethanol in wine or beer as the substances responsible for keeping people hooked, no such clear-cut equivalent exists for food. “It’s very difficult to prove that there are these nutrients in food that directly cause addiction,” says Johannes Hebebrand, a psychiatrist at the University of Duisburg-Essen in Germany.
Yet Ashley Gearhardt, a clinical psychologist at the University of Michigan, argues that highly processed foods are vastly different from what our ancestors used to consume. “Foods that are very high in fat and carbohydrate in a kind of an equal ratio—they don’t exist naturally,” she says. “It’s something that’s designed by food scientists in a laboratory to look a certain way, feel a certain way in your mouth, smell a certain way when you open the package.” A 2021 study showed, for example, that people with binge eating disorder exclusively overeat ultraprocessed foods. “People aren’t losing control over beans,” Gearhardt says.