It seems paradoxical, but often obesity removes the pleasure of enjoying the most caloric foods like sweets: the fault lies with a cerebral peptide connected to the production of dopamine.
Often who is affected by obesity assume large quantities of foodbut without enjoying it: This does not happen in normal -breasted people who, even when they give a little “garbage” food, do it with pleasure. Now a study conducted on mice and published on Nature discovered the possible cause of this phenomenon – a decrease in neurotensin productiona peptide (i.e. a fragment of protein) active in the brain that interacts with the dopaminergic system by inhibiting the feeling of pleasure given by dopamine.
Addiction to garbage food. Contrary to what one might think, eating “without desire” would actually have the effect of making us eat habitually more, favoring obesity: this lack of enjoymenthypothesize the authors, would be unleashed by a long -term consumption of hypercaloric foods. This would cause a reduction of neurotensin in a specific brain region that connects to dopaminergic systemwhich in turn would inhibit dopamine production (a neurotransmitter who communicates the sensations of pleasure).
«A diet rich in fat changes our brain, but we have found a way to restore the desire for hypercaloric foods, which (Paradoxically, we add) It could actually help control the weight », explains Stephan Lammel, one of the authors.
The experiment on mice. The authors therefore observed the behavior of some mice Raised with a diet rich in fat: when they had to choose between food with high fat (over 60%) and “normal” feed (4% fat) in their cages they preferred the fattest pappaand this led them to take weight.
On the contrary, when they came out of the cage and they were given free access to caloric sweets such as chocolate, peanut butter or jam, they showed a lot Less interest than normal -breasted micewho immediately eaten everything. «We notice this paradoxical attenuation of the motivation towards food Only in mice accustomed to a diet rich in fat », underlines Neta Gazit Shimoni, coordinator of the research.
The importance of neurotensin. Scholars saw that when a brain circuit connected to the production of dopamine was stimulated The desire for hypercaloric food increased in normalopropic micewhile remaining unchanged in the obese ones. After discovering the reason (the decrease in neurotensin), the researchers tried to restore the right levels of peptide By following the obese mice a correct diet for two weeks: at that point everything returned to the norm, dopamine has started working again and the mice found the taste for the sweets.
Restoring artificially Neurotensin levels Through a genetic approach, the results were even better: in addition to losing weight, mice have become less anxious and have improved their mobility. The next step, concludes Lammel, is to explore what influences the production of neurotensin and what happens after its action, for develop new targeted therapies to cure obesity in humans.
