A child with a rucksack on wheel walking towards other kids in front of a school as seen through a circular cutoutShare on Pinterest
The prevelance of obesity among children and adolescents has been growing in recent years. Jeff Gritchen/MediaNews Group/Orange County Register via Getty Images
  • Childhood obesity is a growing healthcare challenge, and according to the CDC, one in five American children is obese.
  • Previously, research in obese adults has shown a link with poor brain health, but large studies in children were lacking.
  • Now, researchers have conducted the largest long-term study of brain development and child health in the United States, where they found that higher weight and body mass index (BMI) are associated with negative brain changes.

Obesity is a condition that occurs when a person has excess weight or body fat, affecting their overall health. A doctor or healthcare professional will suggest a person is obese if their BMI is very high.

As part of this research, the study team evaluated data from the Adolescent Brain Cognitive Development (ABCD) study, which includes 11,878 children ages 9-10 years from 21 centers across the U.S.

This dataset closely approximates the U.S. population and is therefore representative with regard to sociodemographics.

After excluding children with disordered eating, neurodevelopmental and psychiatric diseases, or traumatic brain injury, the researchers were left with a study group of 5,169 children (51.9% female).

They reviewed the children’s BMI z-scores. These are measures of the child’s relative weight adjusted for their age, sex, and height, to ensure a standardized approach.

They also used magnetic resonance images (MRI) to identify microstructural or morphological changes in the brains of the children.

Their analysis examined the relationship between the child’s weight, BMI, and changes in the brain.

The researchers concluded that higher weight in childhood is associated with poor brain health, namely changes in white matter, reduced cortical grey matter thickness, and decreased functional connectivity.

The study will be presented at the annual meeting of the Radiological Society of North America (RSNA).

To assess the overall brain health within the study group, the researchers reviewed structural MRI and resting-state functional MRI (fMRI). This allowed the researchers to measure changes in blood flow and, ultimately, brain activity.

They assessed the connectivity between different parts of the brain via the analysis of the resting state fMRI.

The researchers also analyzed data from diffusion tensor imaging, a technique that allowed them to assess the brain’s white matter. They also used restriction spectrum imaging, another advanced MRI technique.

They observed structural brain changes in children with higher weight and BMI z-scores, including significant impairment to the integrity of their brain’s white matter.

Dr. Thomas Booth, consultant diagnostic and interventional neuroradiologist from King’s College London, who was not involved in this research, told Medical News Today that “these are fascinating results in a large cohort highlighting the use of neuroimaging as a basic science.”

Brain health is assessed via a number of factors, such as overall cardiovascular health, the amount of sleep a person gets, the foods they eat, and how much exercise they do.

In this study, the resting-state fMRI images showed that increased weight and BMI z-scores were associated with decreased connectivity in the brain.

The researchers noted that these changes were located in parts of the brain that involve cognitive control, motivation, and reward-based decision-making.

Previously considered a disease of overeating and control, recent research shows that there are multiple factors at play, including genetic susceptibility and brain changes caused by lifestyle or environmental factors.

Haley Bishoff, a registered dietician and owner of Rūtsu Nutrition, who was also not involved in this research, told MNT that “this research helps shed light on why preventing childhood obesity is so important.”

“Brain health and development is crucial during the early stages of life. If there are known risks between childhood obesity and poor cognitive function, it’s important to take preventative action,” Bishoff said.

Bishoff noted the implications of this research for patients and their families:

“This research can help educate families and patients that fall in a high risk category for developing childhood obesity. This comes down to educating children [on] how to live a healthy lifestyle, starting at a young age. A healthy lifestyle includes eating nutritious foods and being physically active on a regular basis.”
— Haley Bishoff

“Children that suffer from obesity tend to eat more processed foods, high fat foods, and added sugars. These foods also lack many nutrients that are essential for brain development, such as protein, omega-3 fatty acids, and B vitamins. Children who eat a diet high in fruits, vegetables, legumes, grains, lean proteins, and healthy fats have lower obesity rates. These foods contribute to healthy brain development,” she detailed.

Bishoff also noted that “regular physical activity is also very important when it comes to weight management and overall brain health.”

On review of the abstract of this research, Dr. Booth highlighted a key question, still to be answered:

“Does the neuronal phenotype in the cohort studied lead to a change in cognition, behavior, or other manifestations?”

“As with much basic science, further work is now needed to understand the clinical importance of such findings,” he concluded.