Here’s Why One Slice Of Pizza Is Never Enough

If you’ve ever thought you were addicted to pizza, you might just be right. A new study from the University of Michigan suggests that some foods really are more addictive than others.

Researchers surveyed people about the foods they can’t put down. The most habit-forming foods typically had two things in common—a high fat content and a high glycemic load, meaning they spike your blood sugar quickly after ingestion. Foods with a high glycemic load tend to be rich in sugars and refined carbs.

Meanwhile, the least addicting foods in the study were cucumbers, carrots, beans without sauce, apples, plain brown rice, broccoli, bananas, salmon, corn without butter or salt, and strawberries.

“We found that people who indicated experiencing symptoms of food addiction reported the most problems with foods with a high glycemic load, where the refined carbs hit the system in a rapid, rewarding manner,” says lead study author Erica Schulte, a doctoral student. “It may be that people who consume food in an addictive manner find the blood sugar spike more rewarding than those who don't report addictive-like eating.”

Previous research suggests that eating sugary foods activates brain regions involved in processing reward.

Fat then adds to the problem. Research shows that eating fats activates brain regions involved in taste and touch, perhaps because the oily and greasy foods feel good in your mouth. “It may be that the combination of the highly rewarding blood sugar spike, with the pleasurable mouthfeel of fat, creates the most ‘addictive’ potential for a food," Schulte says.

Schulte adds that while you can find plenty of high-fat foods, such as nuts, and high-sugar foods, such as bananas, in nature, you won’t find a naturally occurring food with high levels of both sugar and fat.

“This underscores that highly processed foods like chocolate and French fries may be made to be artificially rewarding by containing high quantities of both fat and rapidly absorbed refined carbs,” she says.

Food policies that tax highly processed food or restrict their marketing to children might help curb addictive eating, says Schulte.