Forget abandoning carbohydrates or detoxing. The new dieting craze sweeping Britain and taking off in the United States lets people eat whatever they like - but only five days a week. "The Fast Diet", also known as the 5:2 diet, is the brainchild of TV medical journalist Michael Mosley and journalist Mimi Spencer and allows people to eat what they want for five days but only eat 600 calories a day on the other two. Their book, "The Fast Diet", has topped bestselling book lists in Britain and the United States this year and been reprinted more than a dozen times. Mosley said the diet is based on work by British and U.S. scientists who found intermittent fasting helped people lose more fat, increase insulin sensitivity and cut cholesterol which should mean reduced risk of heart disease and diabetes. He tried this eating regime for a BBC television science programme called "Eat, Fast, Live Longer" last August after finding out his cholesterol level wa