If there is not enough sleep, obesity threatens

People who sleep less than four hours consume about 300 more calories per day than those who sleep an average of nine hours, according to the latest research by American experts.

The extra calories, they found, mainly come from saturated fat, which most often "deposits" around the waist.

13 men and 13 women of normal body weight participated in the research.

"Persons who are chronically sleep-deprived have a huge predisposition to obesity and an increased risk of cardiovascular diseases," experts warn.

They recommend an average of seven to eight hours of sleep, so that people can successfully cope with the challenges of everyday life without fatigue.