According to US researchers overeating causes the brain go haywire, prompting a cascade of damage that may cause serious disease like diabetes, heart disease and other ills,

Eating too much appears to activate a usually dormant immune system pathway in the brain, sending out immune cells to attack and destroy invaders that are not there.

Obesity is a growing global problem, with 1.8 billion people estimated to be overweight or obese in 2007.