Hot New Diet: Eat for 5 Days, Fast for 2 Idea of intermittent fasting arrives in US after sweeping Britain By John Johnson, Newser Staff Posted Mar 2, 2013 12:28 PM CST 31 comments Comments (Shutterstock) (Newser) – The next Atkins? The New York Times says the Fast Diet has the potential to be a blockbuster in the US after becoming a best-seller in Britain. The premise is simple: Eat whatever you want for five days, then fast for two. Well, almost fast: The authors recommend two light meals a day of about 300 calories each on "fasting" days. Jennifer Conlin of the Times sums it up thusly: The "secret to weight loss, according to the book, is that even after just a few hours of fasting, the body begins to turn off the fat-storing mechanisms and turn on the fat-burning systems." Co-author Michael Mosley is a medical journalist who came up with the 5:2 ratio after looking into the idea of intermittent fasting, experimenting on himself, and producing a popular documentary on the subject. The book followed, and the US edition came out last week. Britain's National Health System, meanwhile, cautions that "despite its increasing popularity, there is a great deal of uncertainty about I.F. (intermittent fasting) with significant gaps in the evidence."