An important study finds that teenagers with abdominal obesity have increased areas with brain related to learning and emotion, concerned that excess weight and inequality can disrupt cognitive development and increase the risk of long -term dementia.
Study: Prevalence of national level and state level of overweight and obesity in children, adolescents and adults in the US, 1990-2021, and predicts until 2050. Image Credit: New Africa / Shutterstock
New research that is presented on the European congress on obesity (ECO 2025) has discovered that different brain areas, including regions that play a crucial role in learning and memory and the control of emotions, are greater in adolescents living with obesity.
The finding, from a study by thousands of teenagers in the US, evokes concern that obesity not only influences physical health, but also learning, memory and emotional control, says main investigator Dr. Augusto César F. de Moraes from Uthalth Houston School of Public Health in Austin, Department of Epidemiology, Texas, Texas, Texas, USA. “This is particularly alarming, since the teenage years are such an important moment for brain development,” he adds.
The percentage of children and adolescents worldwide who live more with obesity than quadrupled in girls (from 1.7% to 6.9%) and between boys (from 2.1% to 9.3%) between 1990 and 2022.
In the US it is estimated that more than one in three children aged 5 to 14 (36.2% of boys and 37.2% of girls) live with overweight or obesity, equal to more than 15 million children.
Obesity – in particular abdominal obesity – has been associated with changes in the development of the brain in the past, with regions that are the key to cognition and the regulation of emotions that are particularly vulnerable.
Health inheritances, such as poor access to quality education, safe neighborhoods and healthy food, are well -known contributors to physical health problems, but their role in the development and cognition of the brain is often overlooked.
In order to find out more about how obesity and health inequations influence the brain structure and cognition, Dr. The Moraes and colleagues in the US, Brazil and Spain analyzed data of 3,320 participants in the ABCD study, a racing research project into how child experiences influence brain development and health.
The participants were recruited from cities in 17 states and followed four years, from 2016 to 2018 and 2020 to 2022. The average age of participants at the start was 9.9 years and 47.4% were girls.
They were categorized on the basis of their obesity status, further stratified by obesity of the abdomen (measured using waist circumference). At the start, approximately 34.6% of the participants were classified as belly obesity.
Structural MRI scans assessed the volume of different brain areas of the brain subcortex, including the amygdala, hippocampus, caudate, accumbens, pallidum, putamen and thalamus.
Health differences were assessed with the help of the Child Opportunity Index, which measures the opportunities of a child based on the quality of neighborhood functions such as training, walkability and access to healthy food and green space.
Different brain areas were larger in adolescents with belly obesity than in their peers without obesity. The biggest changes were seen in the Hippocampus, which is involved in memory and learning, and the Amygdala, which regulates or controls emotions, including fear, happiness, anger and fear.
The hippocampus was about 6.6% larger and the amygdala was about 4.3% larger in teenagers with obesity of the abdomen compared to those without.
The amygdala was particularly large with teenagers with a very high levels of belly fat (a waist-height ratio of more than 0.5). The researchers express their concern that surplus body fat influences the way the brain deals with emotions.
The thalamus (which transfers information about movement, hearing, taste, vision and touch) and Caudate (which helps to control movement) showed a smaller increase in size.
The study also showed that teenagers from areas with lower revealability showed a reduced development in important brain regions, such as the Hippocampus, Putamen and Amygdala, compared to their colleagues in areas with a higher Optimal. “This difference was even more pronounced among adolescents with persistent obesity of the belly,” says Dr. The Moraes. “It emphasizes the urgent need to tackle both social inequality and health risks to not only support physical well -being, but also healthy brain development among young people.”
The authors explain that in the context of the young brain, both reduced and increased growth can cause damage. Thus, with a lower than normal brain development, as shown in the teenagers in areas with lower optimized, or larger than normal parts of the brain due to inflammation caused by obesity, both can be harmful.
Dr. The Moraes concludes: “Our findings suggest that obesity, in particular belly obesity, can affect the learning, memory and emotional control of teenagers. I am worried about how these changes that take place at the age of 13 or 14 can influence them later.
“There is even a chance that they can run a higher risk of things such as memory problems or dementia as they get older.
“That is why we find supporting healthier habits so important, not only for physical health, but also for the health of the brain.
“Treating and preventing obesity of adolescents will not only improve health – it can also improve brain health.”
Source:
Journal Reference:
- Prevalentie van nationaal niveau en staatsniveau van overgewicht en obesitas bij kinderen, adolescenten en volwassenen in de VS, 1990-2021, en voorspelt tot 2050 ng, Marie et al. De Lancet, Volume 404, uitgave 10469, 2278 – 2298, The Lancet, Volume 404, uitgave 10469, 2278 – 2298, https://www.thelancet.com/journals/lancet/article/piis0140-6736(24)01548-4/fullentext