Obese people have 8% less brain tissue than their normal-weight peers, says a new study. Their brains look 16 years older than the brains of individuals with normal weight.

"Overweight" people have 4% less brain tissue and their brains seem to have aged prematurely by 8 years.

These results are based on brain scans of 94 people in their 70s, and show "severe brain degeneration," said Paul Thompson, senior author of the study and a UCLA professor of neurology.

"That's a big loss of tissue and it depletes your cognitive reserves, putting you at much greater risk of Alzheimer's and other diseases that attack the brain," said Thompson. "But you can greatly reduce your risk for Alzheimer's, if you can eat healthily and keep your weight under control."

While obesity brings about many negative effects on health - like increased risk of heart disease, type 2 diabeted, hypertension, and some cancers - it has also been known to reduce sexual activity.

Obese people had lost brain tissue in areas of the brain critical for planning and memory, attention and executive functions, long-term memory, and movement.

[via Current]