We've long been overdue a diet that has everybody talking. The last time this happened was when the Atkins Diet captured the imagination of everybody from your hairdresser to your uncle and people bonded in office canteens over lunches of bacon bits and boiled eggs, discussing the best ways of dealing with the dreaded Atkins' breath.
More recently, there have been flirtations with the Dukan (low carb from a French doctor) and the alkaline (basically a rehashing of the old food-combining concept) diets.
But current diet de jour and the thinspirational person's water cooler topic is now the Fast Diet.
It's hotter than the TV series 'Girls' and a pair of Acne Pistol boots combined.
The idea is this: on two days of the week you consume only 500 kcal if you're a woman and 600 kcal if you're a man, bearing in mind that the recommended calorie intake for men and women is usually 2,000 kcal and 2,500 kcal respectively.
Then on the other five, non-fast days, you can pretty much eat what you like – within reason – although you may find that your two fasting days have changed your tastebuds and you no longer feel like chowing down on almond croissants. Results?
According to its advocates, going 5:2 will improve your mood, your overall health, prolong your life by reducing the risks of cancer and diabetes and of course, what everyone really wants to hear: you'll lose weight.
The Fast Diet is seductive, without doubt. Even the name is enticing, suggesting a way of eating that will result in effective and immediate weight loss, and hopefully, not too much pain. And you're not being told you can never have cake again.
While 500 kcal is a pretty meagre amount of food over the course of a day (think 10 apples or five hard boiled eggs), surely it's manageable for two days of the week? Plus, 5:2 has history behind it – intermittent fasting is what our ancestors did millions of years ago, albeit unwillingly – and it's also backed up by some weighty scientific opinion.
The notion came into the mainstream with last year's BBC Horizon programme, 'Eat, Fast and Live Longer'; and the man behind the programme, Dr Michael Mosley, has written a book, 'The Fast Diet', with journalist Mimi Spencer – she says she has lost 20lb and can fit into her wedding dress 12 years on by follow ing the diet. If you're getting a strong sense of deja vu here, so you should be. We've been here so many times before, bowing down at the altar of a miracle way of eating that promises to be the last diet you'll ever try.
All diets work provided you stick to them, whether it's low-carb, low-fat, the Grapefruit diet or the South Beach.
Last year, the American Journal of Clinical Nutrition published its study on diets in which it posited that it's not what you eat, it's how much you eat that matters.
While this would appear to point in the favour of the Fast Diet, you've got to question something where starving yourself for two days of the week becomes the norm.
Don't eat and you're going to be lightheaded and definitely functioning below par – this is not rocket science. Fast Diet advocates claim that you get used to this feeling and say that the mental and physical high you get from not eating becomes almost addictive. And this is veering into dangerous territory.
Although the usual caveats about how the diet isn't suitable for pregnant women, diabetics or anybody suffering with an eating disorder, it's not difficult to see how the Fast Diet could mask disordered eating. Skipping lunch again today? That's okay, because you're on the Fast Diet ...
THE argument could be made that in a society where obesity is such a problem and where you are never far from some highly calorific, nutritionally bereft snack, intermittent fasting isn't such a terrible idea.
It's not, but the bigger issue is how sustainable 5:2 is. Like every other diet that claims to really work, it's difficult not to suspect that within a couple of months, 'The Fast Diet' book will be consigned to the same drawer as the George Formby Lean Mean Grilling Machine, quicker than you can say 'fad diet'.
There's a lot to be said for the 'move more, eat less' ethos, which isn't the magic bullet of weight loss, but is simply common sense.
And it doesn't require you having to buy the book or sign up for any supplements. It might not be fashionable, but straightforward gumption never is.