The study reviewed the brain images of 94 people in their 70s. They were followed for five years, and it was discovered that clinically obese people had 8% less brain tissue, while simply overweight people had 4% less brain tissue compared to normal-weight humans.

“The brains of obese people looked 16 years older than their healthy counterparts, while those of overweight people looked 8 years older,” study leader Paul Thompson said. “This is the first study to show physical evidence in the brain that connects overweight and obesity and cognitive decline.”