Eating large breakfasts high in fat and carbohydrates triggers inflammatory chemicals associated with clogged arteries according to a study in the American Journal of Clinical Nutrition.

Within an hour of a calorific breakfast, scientists discovered, these damaging elements appear and remain at elevated levels for up to four hours, just as people begin their next meal, which - for obese people - is likely to be unhealthy.

Researchers said the nearly continuous state of inflammation explains why obese people are at a higher risk of stokes and heart attacks. Participants' blood was tested before they ingested anything and then for three consecutive hours after eating a 910-calorie breakfast.