A chocolate palm tree, a piece of cake, some cookies, some chips, lasagna… These products have two things in common. The first, that they have a high fat and sugar content and second, that on some occasions we feel hopelessly attracted for them- even knowing that they do not provide any nutrients and that they are harmful to our health.
The “hated” processed and ultra-processed have become the “public enemy number 1” in most Western countries, mainly because of the problems associated with obesity a disease that is becoming more serious and expensive with a high rate of comorbidities (developing diabetes, high blood pressure, heart problems and many other conditions). Therefore, it is essential to know the mechanisms that regulate the attraction to these foods in order to implement measures that mitigate this need.
In this regard, 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 the brain and, if they are consumed regularly, even in small amounts, the brain learn to consume precisely those foods in the future.
“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,” explains Sharmili Edwin Thanarajah, lead author of the study, published in the journal magazine Cell Metabolism.
To test this hypothesis, the researchers gave a group of volunteers a high-fat, high-sugar pudding daily 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 was significantly increased in the group that ate the high-fat, high-sugar pudding after eight weeks. This it especially activated the dopaminergic system, the region of the brain responsible for motivation and reward. Scanning of brain activity showed areas responsible for reward linked to areas that drive automatic and repetitive behavior.
“Our measurements of brain activity showed that the brain reconfigures itself through the consumption of ultra-processed. Subconsciously, you learn to prefer rewarding foods. Through these changes in the brain, we will unconsciously always prefer foods that contain a lot of fat and sugar,” explains Marc Tittgemeyer, who led the study.
During the study period, those who consumed the pudding with more fat and sugar 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 as quickly. After all, the goal of learning is that once you learn something, you don’t forget it so quickly,” adds Tittgemeyer.