Adolescent Obesity Linked to Poor Brain Health 

Using MRI data from the Adolescent Brain Cognitive Development (ABCD) study, research has demonstrated weight and body mass index (BMI) are associated with poor brain health in preadolescence. 

"We know being obese as an adult is associated with poor brain health," said researcher Simone Kaltenhauser, a post-graduate research fellow in radiology and biomedical imaging at the Yale School of Medicine in New Haven, Connecticut. "However, previous studies on children have often focused on small, specific study populations or single aspects of brain health."

As part of the study, both structural MRI and resting-state functional MRI (fMRI) were evaluated. Structural changes observed included impairment to the integrity of the white matter including the corpus callosum, the principal connector between the two hemispheres of the brain. The fMRI images indicated that decreased connectivity in the functional networks of the brain that involve cognitive control, motivation, and reward-based decision making is associated with increased weight and BMI z-scores, measures of relative weight adjusted for a child’s age, sex and height..

The ABCD study originally included 11,878 children aged 9 and 10 years from 21 centers across the US to represent sociodemographic diversity. The study group included 5,169 children (51.9% female) after the exclusion of children with eating disorders, neurodevelopmental and psychiatric diseases, and traumatic brain injury., When the children's BMI z-scores were measured the overweight and obesity rates within the study group were 21% and 17.6%, respectively.

The structural MRI and resting-state fMRI information from the study was evaluated to measure brain activity by detecting changes in blood flow. With resting state fMRI, the connectivity between neural region can be observed when the brain is at rest. Data from diffusion tensor imaging restriction spectrum imaging were evaluated as well.  

"We expected the decrease in cortical thickness among the higher weight and BMI z-score children, as this was found previously in smaller subsamples of the ABCD study," Kaltenhauser said. "However, we were surprised by the extent of white matter impairment."