Preference For Sweets Influenced By Age And Weight

The brain’s reward system may function differently in overweight people compared with individuals classified as being healthy, making those who are battling obesity more prone to eating sweet foods, according to new findings published in the journal Diabetes.

Researchers believe that when young people make it to adulthood, their desires for sweets usually declines. A new study now claims that overweight people may not experience the same drop-off in preferring sweet foods as those who are not obese.

"We believe we may have identified a new abnormality in the relationship between reward response to food and dopamine in the brains of individuals with obesity," said M. Yanina Pepino, PhD, first author of the study. "As we age, we have fewer dopamine receptors in a brain structure, called the striatum, that is critical to the reward system.”

The study puts forth that a correlation exists between young people, fewer dopamine receptors and cravings for sweets in those considered to be of normal weight. Conversely, participants in the study who were considered obese did not enjoy the same experience.

Possible relationship

Researchers looked at 20 participants considered to be of healthy weight and compared them to 24 people identified as obese. The study volunteers - all between the ages of 20 to 40 years old - were given beverages possessing different levels of sugar. Scans were then used to look at dopamine receptors in the brain known to show rewards.

At the conclusion of the study, scientists believed they had discovered a link between overweight people and a craving for sweets that was much higher than the healthy weight individuals in the control group.

Researchers claim that a possible explanation for the findings include higher blood glucose and insulin resistance in the overweight subjects. These factors could potentially alter the brain’s response to sweet foods.

"There is a relationship between insulin resistance and the brain's reward system, so that might have something to do with what we saw in obese subjects," Hershey said. "What's clear is that extra body fat can exert effects not only in how we metabolize food but how our brains perceive rewards when we eat that food, particularly when it's something sweet."

Source: Washington University School of Medicine