London - Forget abandoning carbohydrates or detoxing. The new dieting craze sweeping Europe and the U.S. 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.
Mosley said the diet is based on work by 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 television science program last August after finding out his cholesterol level was too high and his blood sugar in the diabetic range. He was stunned by the results.
"I started doing intermittent fasting a year ago, lost 8 kgs of fat over 3 months and my blood results went back to normal," Mosley says.
Mosley said he had been amazed at the way the diet had taken off with a list of websites set up by followers of the 5:2 diet or variations of the eating regime to share their experiences.
Eating a 600 calorie daily diet - about a quarter of a normal healthy adult's intake - could consist of two eggs for breakfast, grilled chicken and lettuce for lunch, and fish with rice noodles for dinner with nothing to drink but water, black coffee or tea.
One Day At a Time
Mosley put the diet's success down to the fact it is psychologically attractive and leads to steady drop in weight with an average weekly loss of 0.46kg for women and slightly more for men.
"The problem with standard diets is that you feel like you are constantly having to exercise restraint and that means you are thinking about food all the time, which becomes self-defeating," said Mosley.
"On this regime you are only really on a diet two days a week. It is also extremely flexible and simple."
On its website last month the Britain's National Health Service (NHS) said the British Dietetic Association (BDA) reviewed a 2011 study by researchers at the UK's University Hospital of South Manchester that suggested intermittent fasting could help lower the risk of certain obesity-related cancers such as breast cancer.
"The increasing popularity of the 5:2 diet should lead to further research of this kind," the BDA said in a statement.
Schenker, a sports and media dietitian who works with football clubs and food companies, said it was a shame that the NHS had criticized the eating regime that had proved such a success with so many people.
"We are in the midst of an obesity crisis and you need to balance up which is worse - intermittent fasting of staying obese?" Schenker told Reuters.
Despite concerns raised by the NHS, the 5:2 diet has been widely praised by those who follow it.