Scientists have found that obesity is linked to differences in the brain's form and structure, including smaller volumes of gray matter.
The large collection of Magnetic Resonance Imaging (MRI) data can lead to improved insight into exactly which brain structures are involved in all forms of health outcomes like obesity, according to a study published by the journal Radiology on Tuesday.
Researchers from Leiden University analyzed brain imaging results from more than 12,000 participants in the UK Biobank study. They found that having higher levels of fat distributed over the body is associated with smaller volumes of important structures of the brain, including gray matter structures that are located in the center of the brain.
Also, higher total body fat percentage increased the likelihood of microscopic changes to the brain's white matter.
Smaller gray matter volume suggests loss of neurons, while changes to the white matter could adversely affect the transmission of signals within brain networks, said the researchers.
The smaller subcortical grey matter volumes are also known to play a role in the food-reward circuitry, these changes may also make it more difficult for obese people to control their weight.
Those associations are different for men and women, according to the study.
In men, higher total body fat percentage correlated with lower gray matter volume overall and in specific structures involved in the reward circuitry and the movement system.
In women, total body fat only showed a significant negative association with the globus pallidus, a structure involved in voluntary movement.
The reason for obesity's effects on the brain are not precisely known, but there is evidence that cellular responses produced in the brain due to obesity-caused inflammation may be behind these effects.
The findings can provide more information to the understanding of the connection between obesity and negative health consequences such as dementia, according to the study.
