Scientists at University of California have discovered that brains of obese children have a different response to sugar. This elevated sense of 'food reward' involves being motivated by food and deriving a good feeling from it. This could mean some children have brain circuitries that predispose them to crave more sugar throughout life.
The researchers studied brain scans of 23 children to study the early development of the food reward circuitry in pre-adolescents. These children aged 8-12 years were directed to swirl 1/5 teaspoon of sugar-water mix in the mouth with their eyes closed, while focusing on its taste.
Brain images revealed that obese children had heightened activity in the insular cortex and amygdala, regions of the brain involved in perception, emotion, awareness, taste, motivation and reward. Also, the obese children did not show any heightened neuronal activity in the striatum, that is also part of the response-reward circuitry and whose activity has, in other studies, been associated with obesity in adults. However, the striatum does not develop fully until adolescence.
Although the study did not show a causal relationship between sugar hypersensitivity and overeating, it supported the idea that growing number of America's obese youth may have a heightened psychological reward response to sweet food. First author Kerri Boutelle, PhD said, "We could detect the brain differences in children as young as 8 years old, and it was the most remarkable and clinically significant part of the study."
The study is published in International Journal of Obesity.