06/03/2013 16:48 GMT | Updated 06/05/2013 06:12 BST

The Fast Diet: Have Your Cake and Eat It This Easter

So, Easter is on its way, with its glorious high-calorie promise of holiday bingeing and general excess. I must confess that I have never really been one for Lent; as with dieting, giving up something entirely - especially chocolate - is not my style.

Over the course of my 20-year career, I have in fact been emphatically anti-diets, so it may seem odd that I have now written a book devoted to one. It's no U-turn; The Fast Diet, co-written with Dr Michael Mosley, works so brilliantly because you don't have to give anything up at all.

You eat absolutely normally for five days a week and only restrict calories (to a quarter of your usual intake) on two days. So come Easter Sunday, I'll be eating the kids' chocolate eggs, just as I do every year. And on Easter Monday (or even Tuesday, if I fancy a little Bank Holiday indulgence) I will return, guilt free, to my bi-weekly 500-calorie fast.

It is times like Easter that illustrate why the Fast Diet has been so well received. In just two months, we have garnered a huge following and it is the diet's flexibility that seems to be the key to its success: most of the time, there are no awkward dinner-party clichés ('just salad, dressing on the side - I'm on a diet'), no need to be the dull colleague passing on post-work drinks, no need to count or fret.

The diet works because you know that tomorrow you can have that glass of chardonnay/roast dinner/chocolate muffin. If you have ever struggled with the strictures of conventional, every-day dieting, it's a liberating thought.

The book has now reached number one bestselling status on both sides of the Atlantic, which is hugely exciting for Michael and me. While the science is still young, the research is mounting and the results impressive (you can keep up with the conversation at www.thefastdiet.co.uk).

Some of the most common questions we get are about what to eat on the Fast Days; for this reason we are publishing a comprehensive Fast Diet Recipe Book on 2 May, including plenty of information about how the method works, together with more than 180 meal ideas, rich in protein and complex carbs, so you won't find yourself flagging on a fast day.

This Lent, I reckon we can all have our cake and eat it.