Researchers from the U.K.'s Loughborough University and UCL discovered that people with a high body mass index (BMI) and high waist-to-hip ratio had brains that were 12 cubic centimetres smaller than people of a healthy weight.
Links were also found between obesity and shrinkage in specific regions of the brain.
It could be that people with lower volumes of gray matter in certain brain areas are at a higher risk of obesity. Hamer's findings confirmed that trend, since he found that people with high BMI readings and lower waist-to-hip ratios showed similar grey matter volumes to people who were not obese. Researchers then used MRIs to measure the volume of each person's brain.
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The study found that people with both a high BMI and high waist-to-hip ratio had the lowest brain volumes, compared with people who had just a high BMI (but not a high waist-to-hip ratio) and people of a healthy weight. Meanwhile, 3,025 people with overall healthy scores had an average gray matter volume of 798 cubic centimeters. The latest study finds an intriguing link between body fat, especially around the middle, and the brain.
Their brain may already have shrunk, causing them to pile on weight after losing grey matter in the brain regions which help to control your appetite and feel full. White matter contains nerve fiber bundles that connect various regions of the brain. Potential causes of lower brain volume Cara Bohon, an assistant professor in the Department of Psychiatry and Behavioral Sciences at the Stanford University School of Medicine, wrote in an email that the study's findings are "not particularly new or surprising". She also said that something may be affecting both brain volume and risk of obesity. This connection between reduced brain volume and abdominal fat could suggest that inflammation and vascular factors may be at work. Get CNN Health's weekly newsletter Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.
"Our research looked at a large group of people and found obesity, specifically around the middle, may be linked with brain shrinkage". Hamer notes that he recently published data showing how physical activity may increase grey matter, suggesting that exercise may be a way to counteract some of the negative influences obesity might have on the body and brain. "Obesity can have a detrimental impact on a wide range of health parameters", he wrote.