Study links CHILDHOOD OBESITY to thinner brain cortex and impaired cognitive function
By dominguez // 2025-10-14
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  • Yale researchers found that children with higher BMI show cortical thinning and white matter damage, indicating impaired cognitive development.
  • The large-scale study analyzed MRI scans from 5,169 children (aged 9-10) in the ABCD study and found 21 percent of those with high BMI scores were overweight while 17.6 percent were obese.
  • Structural brain changes could explain poorer academic performance in obese children, linking high BMI to memory, attention and executive function deficits.
  • Obesity-related inflammation, insulin resistance and reduced brain blood flow could drive these changes, but long-term studies are needed to prove causality.
  • Early nutrition and lifestyle interventions may help, but preventing childhood obesity is critical to protect long-term brain health.
Childhood obesity is widely known to increase the risk of chronic diseases like Type 2 diabetes and hypertension. But emerging research suggests excess weight may also harm brain development at a critical stage, raising concerns about long-term cognitive function. A study led by Yale School of Medicine researchers, presented at the 2022 meeting of the Radiological Society of North America (RSNA), reveals that children with high body mass index (BMI) scores show structural brain changes, including thinning cortices and damaged white matter—key indicators of impaired cognitive health. The findings, based on MRI scans from over 5,100 children aged nine to ten, highlight the urgent need to address obesity's neurological impact before adolescence.

Structural changes found in the brains of obese children

Simone Kaltenhauser, a post-graduate research fellow in radiology and biomedical imaging at Yale, spearheaded the research which used data from the Adolescent Brain Cognitive Development (ABCD) study—a nationwide dataset encompassing 11,878 children from 21 research centers. After excluding participants with pre-existing conditions like eating disorders or traumatic brain injuries, the team analyzed MRI scans from 5,169 children, categorizing them by BMI z-scores (adjusted for age, sex and height). Among them, 21 percent were overweight, and 17.6 percent were obese. Using advanced imaging techniques—structural MRI, resting-state functional MRI (fMRI) and diffusion tensor imaging—the researchers assessed brain structure and connectivity. The results were striking: Children with higher BMI z-scores exhibited significant cortical thinning, particularly in regions governing cognitive function. Additionally, their white matter—especially in the corpus callosum, which facilitates communication between brain hemispheres—showed signs of damage. "It is striking that these changes were visible early on during childhood," Kaltenhauser said. "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. However, we were surprised by the extent of white matter impairment." According to BrightU.AI's Enoch engine, premature cortical thinning accelerates brain aging, impairing sensory processing and higher-order cognitive functions, and potentially leads to early cognitive decline—mirroring the neural degradation seen in aging adults but occurring in children.

Obesity and cognitive impairment

Senior author Dr. Sam Payabvash, a neuroradiologist at Yale, emphasized that these structural changes may explain why obese children often struggle academically. Previous studies have linked high BMI in youth to poorer memory, attention and executive function. The new findings provide a biological basis for those observations, suggesting obesity doesn't just affect physical health—it may alter brain development during a critical window. The study builds on growing evidence that childhood obesity has far-reaching neurological consequences. A 2019 study published in Cerebral Cortex found similar cortical thinning in obese adolescents, while research published in JAMA Pediatrics associated high BMI with lower IQ scores in children. While the study confirms a correlation between obesity and brain changes, the exact mechanisms remain unclear. Potential factors include inflammation from excess fat tissue, insulin resistance and reduced blood flow to the brain. Payabvash advocates for longitudinal studies tracking obese children into adolescence to see how the brain changes evolve. Another pressing question is reversibility: Can weight loss or lifestyle interventions restore brain health? Preliminary studies suggest yes. A 2022 study published in JAMA Network Open found that regular exercise significantly improved intelligence and cognitive flexibility among overweight or obese children. However, experts stress that prevention—through better nutrition and reduced screen time—is ideal. The Yale-led study adds to mounting evidence that childhood obesity doesn't just harm the body—it also reshapes the brain. With nearly one in five U.S. children classified as obese, the findings underscore the urgency of early intervention. As Kaltenhauser noted, the structural changes appear "early on," making childhood a critical period for action. While further research is needed to confirm causality and explore solutions, the message is clear: Protecting kids' physical health may also safeguard their minds. Learn about childhood obesity, environmental toxins and child health by watching the video below. This video is from the DrSergeTheNutritionScientist channel on Brighteon.com. Sources include: StudyFinds.org RSNA.org Academic.OUP.com JAMANetwork.com 1 JAMANetwork.com 2 BrightU.ai Brighteon.com
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