UCSD researchers found that the brains of obese children respond to sugar differently than non-obese children’s brains do. Although the findings suggest that obese children have a higher “food reward” than healthy children, the study did not find any causal relationship between hypersensitivity to sugar and overeating, according to a UCSD News Center article.

Brain scans of 23 children ages 8 to 10 showed that the ten obese children had an elevated reward from sugar than the 13 children of healthy body weights. The children were instructed to swish sugar water in their mouths, focusing on the taste. Enjoying the taste of sugar was controlled for, along with other confounding conditions such as psychiatric disorders or ADHD. 

“The take-home message is that obese children, compared to healthy-weight children, have enhanced responses in the brain to sugar,” author and Professor of Pediatrics and Psychiatry Kerri Boutelle said in the UCSD News Center article. “That we can detect these brain differences in children as young as 8 years old is the most remarkable and clinically significant part of the study.”

The areas of heightened activity in the obese children were the insular cortex and the amygdala, both of which are associated with reward. However, the third brain structure typically associated with reward, the striatum, was not more active in the obese children than in the healthy children. According to the News Center article, increased activity in the striatum has been associated with obesity in adults. However, the striatum does not fully develop until adolescence.