Obesity in children associated with poor brain health

In a recent study, researchers observed structural changes to the brains of children with a higher body mass index (BMI) which have been associated with worsened executive function, cognitive control, motivation, and reward-based decision making.

Findings from the study are being presented Monday at the annual meeting of the Radiological Society of North America (RSNA). Led by Simone Kaltenhauser, PhD, a research fellow in radiology and biomedical imaging at the Yale School of Medicine in New Haven, Connecticut, the study sought to reveal the effect of obesity on the brains of children. To do this, Kaltenhauser and her colleagues used magnetic resonance imaging (MRI) data to conduct a large long-term study of brain development in children in the United States.

Kalterhauser’s study included imaging data from 5,169 children aged nine to 10 years old who represented U.S. sociodemographic diversity. Of the study subjects, 51.9 percent of them were female, 21 percent were overweight, and 17.6 percent qualified as obese. Children with eating disorders, neurodevelopmental and psychiatric diseases, and traumatic brain injury were excluded from the study.

Researchers analyzed the children’s brains using data from structural MRI, resting state fMRI, restriction spectrum imaging, and diffusion tensor technique. Through these data, scientists were able to observe the participants' brain structure, activity, and white matter.

Results showed a link between children with higher BMI z-scores and structural brain changes. One of the most significant changes observed was impairment to the white matter of the corpus callosum, which connects the brain's two hemisperes. In addition, scientists observed a thinning of the outermost layer of the cortex which could cause impaired cognitive function. Findings also indicated an association between higher BMI and decreased connectivity in the functional networks of the brain that relate to cognitive control, motivation, and reward-based decision making.

According to the study’s authors, these findings suggest that obesity can negatively impact the brain health of children.

“Increased BMI and weight are not only associated with physical health consequences but also with brain health,” said Kaltenhauser in a statement. “Our study showed that higher weight and BMI z-scores in 9- and 10-year-olds were associated with changes in macrostructures, microstructures and functional connectivity that worsened brain health.”