Researchers from the Max Planck Institute for Metabolic Research in Cologne (Germany), in collaboration with Yale University (United States), have shown that foods high in fat and sugar alter our brain: if we regularly eat even small amounts of them, the brain learns to consume precisely those foods in the future.
Why do we love unhealthy and fattening products so much? How does this preference develop in the brain? “Our tendency to eat foods high in fat and sugar, the so-called Western diet, could be innate or develop as a consequence of being overweight. But we believe that the brain learns this preference,” said Sharmili Edwin Thanarajah, lead author of the study.
To test this hypothesis, the researchers gave a group of volunteers a small pudding containing a lot of fat and sugar every day for eight weeks, in addition to their normal diet.
The other group received a pudding that contained the same number of calories but less fat. The volunteers’ brain activity was measured before and during the eight weeks.
The brain’s response to high-fat, high-sugar foods increased significantly in the group that ate the high-sugar, high-fat pudding after eight weeks. This especially activated the dopaminergic system, the region of the brain responsible for motivation and reward.
“Our measurements of brain activity showed that the brain rewires itself through the consumption of French fries and company. It subconsciously learns to prefer rewarding foods. Through these changes in the brain, we will always subconsciously prefer foods that contain a lot of fat and sugar,” detailed Marc Tittgemeyer, who led the study.
During the study period, the subjects who ate the pudding high in sugars and fats did not gain more weight than those in the control group, and their blood values, such as sugar or cholesterol, did not change either.
However, the researchers assume that the preference for sugary foods will continue after the end of the study. “New connections are created in the brain, and they don’t dissolve so quickly. After all, the goal of learning is that, once you learn something, you don’t forget it so quickly,” Tittgemeyer explained.
