Scientists say crucial brain circuits begin to form early in life so people may have a tendency towards obesity even before they eat their first meal.（Internet）
An international study has discovered why some people who eat a high-fat diet remain slim, yet others pile on the weight.
Researchers found in some people a high-fat diet causes the brain cells to become insulated from the body.
This prevents vital signals, which tell the body to stop eating and to burn calories through exercise, from reaching the brain.
The team from Monash University, Australia, said the findings provide a critical link in addressing the obesity epidemic.
Lead author Professor Michael Cowley, said: 'These neuronal circuits regulate eating behaviours and energy expenditure and are a naturally occurring process in the brain.
'The circuits begin to form early in life so that people may have a tendency towards obesity even before they eat their first meal,' he said.
Eating a high fat diet causes more 'insulation' in the nerve cells, and makes it even harder for the brain to help a person lose weight.
Professor Cowley said: 'Obese people are not necessarily lacking willpower. Their brains do not know how full or how much fat they have stored, so the brain does not tell the body to stop refuelling. Subsequently, their body's ability to lose weight is significantly reduced.'