Young people have a natural preference for sweet snacks. However, as they get older, their tastes seem to change. The drop-off in people with obesity, on the other hand, might not be as fast.
According to new studies, there might be an explanation for this phenomenon. It’s possible that the brain’s reward system functions differently in fat people than in skinny people.
The researchers looked at 44 people. Twenty of the people were of average weight, and the other 24 were obese.
Each individual tasted a variety of drinks with differing levels of sugar to determine their desired sweetness level. The researchers then used PET scans to locate the dopamine receptors in the participants’ brains that are connected to incentives. There is a compound in your brain that makes you feel good.
“We discovered that in people of average weight, a greater appetite for candy is correlated with both younger age and fewer dopamine receptors. In our research, however, that was not the case in obese people,” said first author M. Yanina Pepino, PhD.
Obese people tended to have a distinct reward system. The association between sweetness tastes and dopamine receptors in overweight people did not follow the same trend as in average weight people.
Since some of the obese participants have elevated blood glucose and insulin concentrations, the research authors believe this is due to insulin tolerance or other physiological changes related to obesity. Some of them were also developing insulin resistance.
The researchers suggest that as these mechanisms are combined, they will change how the brain reacts to sweets.
“There is a connection between insulin resistance and the reward system in the brain, so that may explain what we found in obese subjects,” co-author Tamara Hershey, PhD, said.
“What’s obvious is that excess body fat has an impact not just on how we metabolize food, but also on how our brains experience benefits when we consume that food, particularly if it’s sweet.”
SOURCE: Age, obesity, dopamine appear to influence preference for sweet foods. News Release. Washington University School of Medicine in St. Louis.