Obese individuals have an average of 8 percent less brain tissue than people who are a normal weight, according to a joint study performed by the UCLA Laboratory of Neuro Imaging and the University of Pittsburgh School of Medicine. Overweight individuals were found to have four percent less brain tissue than people of a normal weight.
The study compared the differences in brain structure of elderly people who were considered obese, overweight, and of normal weight, based on their Body Mass Index (BMI). Normal weight people have a BMI of 18.5-25, overweight people have a BMI of 25-30, and obese people have a BMI over 30.
To perform the study, researchers used brain images from the Cardiovascular Health Cognition Study, which was performed earlier by the University of Pittsburgh School of Medicine. The brain scans of 94 healthy (not cognitively impaired), elderly people in their 70s, five years after the scan was taken, were used. The researchers converted the scans into detailed three-dimensional images that display high-resolution mapping of anatomical differences in the brain, and then looked at both the gray and white matter of the brain.
According to the research, the brains of obese people looked 16 years older than the brains of those who were normal weight, and the brains of overweight people looked eight years older.
The research for this study was funded by the National Institute on Aging, the National Institute of Biomedical Imaging and Bioengineering, the National Center for Research Resources, and the American Heart Association.