You have likely experienced intense carbohydrate cravings a few hours after a breakfast high in starchy foods (pancakes anyone?) or a few hours after a French fry–laden lunch complete with a sandwich and sugary beverage. Sound familiar?

These cravings have long been blamed for the blood sugar drop experienced after the initial increase after eating a high-carbohydrate meal. There is more to these cravings than blood sugar metabolism, however. It is thought that these cravings actually occur due to addiction-like processes in the brain triggered by such meals. Researchers from Harvard University took an in-depth look at the potential addictive qualities of a starchy meal in a study published in The American Journal of Clinical Nutrition.

The researchers measured blood sugar levels and hunger, and used functional magnetic resonance imaging (MRI) to observe brain activity for four hours after eating a meal that consisted of a high-glycemic index (GI) milkshake for half of the participants and a low-glycemic index shake in the other half. (Glycemic index is a measure of the foods ability to raise blood sugar. In general, high glycemic-index foods contain a high amount of starchy carbohydrates and sugars while low-glycemic index foods contain much less.)

In participants consuming the high GI milkshake blood sugar levels spiked followed by a sharp crash four hours later. This decrease in blood sugar was associated with excessive hunger and an intense activation in the nucleus accumbens in the brain, the brain region that plays a crucial role in reward, pleasure, impulsivity, and addiction.

“In a way the results support the notion that [obesity] is addiction related,” stated Belinda Lennerz, MD, PhD, one of the researchers. “If you look at the data there is a strong correlation between the rising obesity rates and the increase in the consumption of highly processed foods and soft drinks. This may just mean that either all of us or at least a subset of us is not equipped to deal with that environment.”

We have all felt the pull of sweets and breads. And we have often succumbed to such cravings. How to stop the cycle? Replace starchy carbohydrates and sugars with high-fiber vegetables and fruits. Eat plenty of lean proteins throughout the day. And eat healthy fats. Our diets are way too high in nutrient-poor carbohydrates. We don’t need them, despite what our cravings tell us.