A new research published in Am J Clin Nutr. June 26, 2013 found that consumption of a high glycemic index (GI) meal found in refined carbohydrates increased hunger and selectively stimulated brain regions related to craving and reward 4 hours after eating — a critical time point that influences eating behavior at the next meal. This finding supports the controversial hypothesis of food addiction.

The study showed that refined carbohydrates can have biological effects on people with symptoms similar to addiction, independent of calories and tastiness according to the study’s principal investigator, David Ludwig, MD, from Boston Children’s Hospital.

Participants were given either a low-GI meal (slow-acting carbohydrate) or a high-GI meal (fast-acting carbohydrate). The participants underwent a final blood glucose test and neuroimaging, and rated their hunger levels 4 hours after the meal.

Participants consumed high GI meal reported excessive hunger 4 hours later. They also initially had a surge in blood glucose level that was 2.4-fold higher than the low-GI meal participants, followed by a crash in blood glucose at 4 hours. Functional magnetic resonance imaging (fMRI) showed intense activation in the area of brain related to addiction in every single participant with high GI meal.

The results show that highly processed carbohydrates, such as white bread, potatoes, and concentrated sugar, “alter brain activity in ways that make us crave them even more,” Dr. Ludwig said. (read more)