Summary: A large national study finds that preteens with excess weight show significant differences in cognitive performance, brain structures, and brain circuitry when compared to those with normal body-mass index.
Although the study cannot establish causation, it suggests a significant association between BMI and brain measures, raising concerns about tracking adolescent brain health and intervening through lifestyle modifications.
The study found significant differences in cognitive performance, brain structures, and brain circuitry between preteens with excess weight and those with normal BMI.
Preteens with excess BMI showed less efficiently organized and connected brain circuits supporting cognitive functions, reward, emotional processing, and attention.
The study highlights the importance of tracking adolescent brain health and intervening through lifestyle modifications such as mental health screenings, improving sleep and physical activity, and reducing screen time.
Source: Boston Children’s Hospital
Obesity is a growing epidemic in children and adults. A large national study published in the International Journal of Obesity now finds that preteens carrying excess weight have notable differences in cognitive performance, brain structures, and brain circuitry when compared to preteens with normal body-mass index (BMI).
Funded by the National Science Foundation’s Harnessing the Data Revolution initiative, the study involved nearly 5,000 9- to 10-year-olds at 21 sites across the United States. While it only examines the relationship between BMI and the brain and cannot establish causation, there is a significant association between BMI and brain measures in the study.
Study leader Caterina Stamoulis, PhD, a researcher in Adolescent Medicine and director of the Computational Neuroscience Laboratory at Boston Children’s Hospital, finds the association concerning.
“It raises an alarm that it’s important to track adolescents’ brain health, especially when they have excess BMI,” she says. “Early adolescence is a time when the brain is very actively developing, and when frontal areas of the brain — those involved in higher cognitive functions — change enormously and are vulnerable to miswiring.”
Inefficiently organized brain networks
The study drew its subjects from the government-funded Adolescent Brain Cognitive Development (ABCD) study, which has collected detailed clinical, physiological, environmental, and lifestyle information, together with neuroimaging and neurocognitive data. Stamoulis and colleagues in her lab use advanced computational methods to analyze the large data sets.
In preteens with excess BMI, brain circuits supporting higher-level cognitive functions, reward, emotional processing, and attention were found to be organized less efficiently, less well connected, and less resilient than in preteens with normal BMI.
Excess BMI was correlated with difference in multiple brain structures, as well as a lower ability to think logically and solve problems in new settings. The differences were consistent even after adjusting for factors like sleep duration, screen time, physical activity, depression, and self-worth related to weight that may affect both BMI and brain health.
Whether BMI plays a direct causative role or not in brain development, Stamoulis emphasizes that preteens’ brains are still changing, and that interventions can make a difference — whether they be mental health screenings, improving sleep quantity and quality, increasing physical activity, or reducing screen time.
A stake in the ground
Stamoulis now plans to analyze two-year follow-up data from additional waves of the ABCD datasets to see what happens to the brains of kids with excess BMI over time. “Once the brain is done wiring, it’s more difficult to intervene,” she says. “We want to see what neurodevelopmental trajectories these youth are on.”
She also hopes to analyze genetic and nutritional data, which the ABCD study plans to release in the future.
About this neurodevelopment and obesity research news
Excess BMI in early adolescence adversely impacts maturating functional circuits supporting high-level cognition and their structural correlates
Adverse effects of excess BMI (affecting 1 in 5 children in the US) on brain circuits during neurodevelopmentally vulnerable periods are incompletely understood. This study investigated BMI-related alterations in maturating functional networks and their underlying brain structures, and high-level cognition in early adolescence.
Cross-sectional resting-state fMRI, structural sMRI, neurocognitive task scores, and BMI from 4922 youth [median (IQR) age = 120.0 (13.0) months, 2572 females (52.25%)] from the Adolescent Brain Cognitive Development (ABCD) cohort were analyzed. Comprehensive topological and morphometric network properties were estimated from fMRI and sMRI, respectively. Cross-validated linear regression models assessed correlations with BMI. Results were reproduced across multiple fMRI datasets.
Almost 30% of youth had excess BMI, including 736 (15.0%) with overweight and 672 (13.7%) with obesity, and statistically more Black and Hispanic compared to white, Asian and non-Hispanic youth (p < 0.01). Those with obesity or overweight were less physically active, slept less than recommended, snored more frequently, and spent more time using an electronic device (p < 0.01).
They also had lower topological efficiency, resilience, connectivity, connectedness and clustering in Default-Mode, dorsal attention, salience, control, limbic, and reward networks (p ≤ 0.04, Cohen’s d: 0.07-0.39). Lower cortico-thalamic efficiency and connectivity were estimated only in youth with obesity (p < 0.01, Cohen’s d: 0.09-0.19).
Both groups had lower cortical thickness, volume and white matter intensity in these networks’ constituent structures, particularly anterior cingulate, entorhinal, prefrontal, and lateral occipital cortices (p < 0.01, Cohen’s d: 0.12-0.30), which also mediated inverse relationships between BMI and regional functional topologies. Youth with obesity or overweight had lower scores in a task measuring fluid reasoning – a core aspect of cognitive function, which were partially correlated with topological changes (p ≤ 0.04).
Excess BMI in early adolescence may be associated with profound aberrant topological alterations in maturating functional circuits and underdeveloped brain structures that adversely impact core aspects of cognitive function.