Any diet which begins with the words "Eat whatever you want" is okay with me. That's the first golden rule of the Paul McKenna diet, shown last week in five episodes on the Living TV channel which I lapped up every night, hoping that this might be the ultimate foody diet. Now I find that it's all the rage! Lily Allen's at it, and Sophie Dahl too, and apparently "it's very big in LA and New York" too.

So I'm revelling in the feeling of not only being in the early stages of a non-diet which so far is pretty blooming easy, but also being (for once in my life) utterly and completely with it. Me, Lily and Sophie: it's not a group I ever thought would exist.

First off, why am I dieting? I took a vow last year never to do it again after a hellish experience with that carb-free nonsense which pitched me deep into depression. But there is an annoying spare tyre to consider, and an extra chin which I hate. My youngest child is three so I can no longer blame pregnancy. I want my old jawline back. The answer, I'm hoping, is not to diet, but to hypno-diet. Paul McKenna claims his method is different to every other diet, in fact not a diet at all, so I feel as if I'm not entirely breaking my vow.

You're wondering what fool (I actually typed food there to start with - perhaps my subconscious is not quite as firmly under control as I like to believe) might believe in this hypno-dieting, aren't you. Well, put away ideas of swinging watches and counting backwards for a start: that kind of hypnotism, where groups of people wander round a stage thinking they can smell onions, is mostly just stagecraft. In Derren Brown's autobiography he explains that stage hypnotism only works when you choose the most suggestible person in a line-up: certain types of people will go amazingly far with whatever you tell them to do. So the associations we have with hypnotism - of men with glittery eyes and monotone voices - are really all wrong: in fact it's all about suggestible states of mind and repetition. That sort of thing I can live with.

What about the Paul McKenna system though, how does it work? Well firstly there are the four golden rules: eat whatever you want, eat when you're genuinely hungry, eat consciously, and stop when you're full. It must be said that these show off McKenna's sneaky hypnotic genius straightaway: they look like they're giving you everything you want and actually they're going to get you to eat quite a lot less. Eating only when you're actually hungry, for a start, is quite hard, while consciously is a whole art: you have to sit at a table with no book or newspaper or TV and carefully chew every mouthful, which is the diametric opposite to how I usually eat.

McKenna also shows us techniques for dealing with cravings, and to motivate ourselves to get up and exercise. These, I have to say, are hilarious, and McKenna is in full "Look into my eyes" mode as he urges us to visualise the foods we crave mixed in with something we hate, with hair from a barbershop and spit on top (it really makes you gag, which of course is the idea), while pinching our left middle finger and thumb together.

Then we have to visualise a wonderful time in our lives ("feel what you felt, hear what you heard, smell what you smelt" urges McKenna evangelistically) while pinching our middle right fingers and thumbs together. Finally there is a tapping exercise where, when you get an emotional craving for food you tap certain points on your body (acupuncture points, says McKenna very vaguely) to take away the cravings.

I suspect this is from his neuro-linguistic programming stuff: I'm slightly embarrassed to admit that I have tried this and it kind of works. It makes you think of something else, like how stupid you feel, and surely that, in itself, is good enough?

So am I an idiot? Yes, but I was an idiot before I watched Paul McKenna. Am I any thinner? Well, I've only been doing it for a week, but I have to admit that I like it. I like the fact that I can eat what I want. I am definitely eating less, at the moment. So far, to be honest, it's been absurdly easy.

And that's what I like about it: I've always believed really that if we live right we should be the right size without a lot of effort. I don't want to be a skinnymalink, I just want to be able to glance at my stomach without wincing, and I don't think I should be tipped into depression and deprived of chocolate and bread in order to get there. But am I deluded? Am I living in a McKenna dreamworld? Should dieting always involve suffering?