The victims of permarexia

On the bus to my home in Willesden last night I spent the whole time wondering what I was going to eat. Would I have pasta? No, because wheat makes you bloat. Soup? No, I'd still be hungry. Atkins-style dinner? No, I don't have the money to eat steak every night. I know it's stupid but I think about food all the time and it drives me crazy.

I sometimes start the day on one diet - the Cornflake Diet where you replace two of your meals with cornflakes for a fortnight - and end it on another.

I'm 29 now and have been on a diet constantly since I was 23. Even though I know I'm fairly normal, with the right weight - nearly nine stone - and a healthy life, I spend my whole time feeling fat. I'm a classic permarexic: I only come off one diet to start another.

I read about all the diets out there: the Zone, the South Beach Diet, the Blood-Type Diet, and I plan to go on all of them eventually. Of course some of them are much too complicated, even though I'm tempted - the Kate Winslet Facial Analysis Diet just takes too much planning and shopping. I'd love to find a diet that fitted into my lifestyle as well as Jennifer Aniston's but I can't go home and make up a dish of salmon, prawns and salad every night. I work as a receptionist, so it's too expensive for me to eat like that.

But that doesn't stop me trying. At the moment I'm on WeightWatchers and eating six small meals a day. The last diet I was on was Atkins and I lost about half a stone, but after six weeks I got palpitations and felt like my arteries were going to explode with bacon and sausages.

I tried the Cabbage Soup Diet where you're supposed to lose 10lb in a week, but it tasted awful and after four days I stopped because it makes you flatulent.

At school I ate nothing but popcorn for a week because I heard that Madonna had done it, until my mum found out and stopped me.

I know about all the celebrity diet plans, such as the ones followed by Martine McCutcheon, Jennifer Aniston, and Catherine Zeta-Jones. I even get a magazine called Celebrity Star Diets which features celebs' current diet plans.

There's such a deluge of information out there it's bewildering: one minute apples are healthy and the next you're not supposed to eat them because they contain too much acid. At the moment the big thing is the healthier way of doing Atkins, which just means less fat.

Right now I'd like to lose a stone and a half and be a size 10 - I'm currently a size 12.

About a quarter of women are on a diet, and when I go out to lunch with friends it's a nightmare. One friend, a size-eight management consultant, doesn't eat wheat, another refuses carbs altogether, and a few friends who work in TV are currently going to WeightWatchers with me. We'll look at the menu, then order soup and salad. I don't eat things that are unhealthy, I guess I just eat too much.

I suppose much of the problem is that I don't have the willpower to stay on a healthy eating regime. It's almost as if the strength I need comes from copying what others do. Then I worry about being too insecure and end up ditching the diet for something else.

I think permarexia is more of a psychological syndrome than a physical one - we're conditioned to think we should look like someone else when, in fact, we're fine the way we are. But maybe - just maybe - this new diet will help us get the job and boyfriend we want. I'm single at the moment, but all my past boyfriends have said I have a great figure. It's always difficult for a girl to trust what they say.

It seems ridiculous that celebrity plans have such a big impact on our lifestyles. Supermarket sales of red meat, watermelons and pork scratchings have soared because of Atkins, while sandwich shops around Notting Hill are virtually empty because people are off bread - everyone's eating organic juices and salads instead.

Because I'm bubbly, people don't know how deeply eating and diets affect me. I recently refused a holiday with friends because I'm fatter than them and don't always want to be the one "with the nice personality".

The other night I was supposed to be going out for dinner and found I couldn't get into tops I wore three months ago. I felt hideous and went to bed crying with an armful of comfort food.

It's as if there are two sides to my personality: on the one hand I know I look fine and there are more important things in life than being skinny; on the other hand, pictures of celebrities are constantly in my face, and feeling fat and ugly dominates every day. I'm not sure whether I'm normal or abnormal, whether my attitude is misguided or merely experimental, but it has almost become an obsession now and one which I wish I didn't have.

I'd love to wake up one day and not think about what I'm going to eat. But most mornings I go into the shower and take a look at myself and think "oh, no". Tearing strips off myself for not looking like an ideal is miserable and exhausting. I only told friends recently how much it got to me, because it had reached the stage where if they told me their problems I'd be thinking: "So what! Shut up, it's doesn't matter: you're thin."

All I really want is to be healthy and to stop thinking about dieting, so now I'm going to see a nutritionist. Hopefully in a while I'll be able to go out for lunch with friends and just think about what I want to eat that's healthy and not see everything in terms of calories.