We will have to wait to find out how this megastar shed the pounds.

The singer confirmed she is writing a book on weight loss in an interview with Billboard Magazine. She said the book will serve as a how to guide to shedding fat. It is expected to be released at the end of 2008.

She said: "Everybody asks me - men, women - how did I do it? Even young people will come up to me and they have an issue with their weight and they're very concerned. So it's basically my journey."