Obesity linked to smaller brain size, study says

Brain volume is not linked to a person's intelligence

Obesity lends itself to several chronic health problems. A recent study is linking extra body fat to brain size. 

The study examined data on 9,652 people with an average age of 55. Researchers looked at measurements of each person's BMI, waist-to-hip ration, and overall body fat and used MRI scans to examine the brain volume of the participants. 

“What they found was that whether you take BMI, or whether you take the waist-to-hip ratio, they both appear to be related to smaller brain volumes in the obese,” said Dr. Jagan Pillai, of Cleveland Clinic, who did not take part in the study.

People with the highest BMIs not only had lower brain volume, but also lower gray matter. Gray matter is the part of the brain that regulates muscle control, memory, sensory perception, and speech, among other things. 

The study authors said the connection between less brain volume and high BMI was not as significant for those participants who were overweight, but not obese.

Dr. Pillai points out that brain volume is not linked to a person’s intelligence, and that brains come in all sizes.

However, he said the study results should encourage us to do our best to keep our numbers below the obesity level, as there appears to be a connection between body fat and the brain.

“The underlying theme that a healthy lifestyle – as defined by good physical activity, and a heart-healthy diet – we know this is helpful for you; there’s no question about it,” said Dr. Pillai. 

You can find the complete results of the study here.