Picture the scene. It is 5.30 in the afternoon and I am sitting at a table surrounded by three assorted bars of milk chocolate, a pot of Haagen-Dazs ice-cream, a croissant and a jam doughnut. No, I am not Bessie Bunter but trying out the latest diet to hit our shores from the United States. 'The Carbohydrate Addict's Diet' promises to be your lifelong solution to weight control. I thought I had seen them all - calorie-controlled, fat-free, milkshake, diet cookie, banana diets - but this one really takes the biscuit.

Let me put my cards on the table here and now. I am not a serious dieter. I have never lost weight nor have I stuck to any sort of eating (or starving) plan for more than two weeks at a time. I am about 10 pounds heavier than I ought to be, and it is only the thought of summer holidays and swimming costumes that force me to consider my excess baggage.

So what are the rules of this latest wonder diet that promises to stop the weight loss/weight gain see-saw for ever? I am allowed three meals a day, two of which should contain no carbohydrates. That means I can have protein and green salad or certain vegetables only. No fruit, bread, pasta, potatoes . . .

That is the bad news. The good bit is that I am 'rewarded' at the third meal - which may be eaten at any time of the day. The diet recommends a balanced meal, including pasta, bread, dessert and fruit, but allows me to have whatever I want - provided I take no longer than 60 minutes to eat it.

The strict time limit, apparently, is all to do with fooling the body into thinking that you are not really eating very much. And this is where it starts to get technical.

When blood glucose levels are high - for example, when you eat high-carbohydrate foods - the pancreas is stimulated to produce insulin, which promotes absorption of glucose by the liver and the muscles (where it is stored as energy). The production of insulin also produces those gnawing hunger pangs. The one-hour deadline on the 'reward' meal is supposed to ensure that not too much insulin is released into the system - thus limiting the hunger pangs.

Weight loss should be gradual, no more than 2lbs a week, but the promise is that if you stick to this pattern of eating permanently, your excess weight will come off and stay off.

Dr Rachael Heller, who discovered the diet, was a long-term fatty who has now been a slim eight stone for several years. She claims to have helped hundreds, even thousands, of people through the Carbohydrate Centre that she and her husband, Richard, have established in New York.

This was too good to pass up, I thought. Eat whatever you want for your 'reward' meal and still lose weight? This is too good to be true so I decided to put the diet to the test.

A late protein breakfast consisting of cheese omelette or kippers and salad at around 11am or later, did banish all feelings of hunger until at least 5pm. Since this has traditionally been the 'nibbling' time of day for me I decided to take my reward meal then. I'm afraid that I ignored all concept of a balanced meal and my meal consisted entirely of foods that I have been limiting or denying myself for months.

For the first two weeks I made regular sorties to the local newsagent to ensure I had abundant supplies of chocolate. A typical reward meal would consist of three different bars of chocolate and any other fattening cakes that had tempted me from the bakery window, topped up with the latest flavour in American ice cream. I wasn't going to waste this hour on boring foods like pasta or bread. I was like a child being let loose in a sweet shop.

I am absolutely positive that my intake of chocolate in those two weeks far exceeded the total of this whole year's intake though interestingly enough I found it difficult to eat at this prodigious rate for a whole hour.

Four weeks on, and although I eat enormous quantities of former 'forbidden foods', I have now added more sensible foods like macaroni cheese or fish and chips to my 'happy hour', as it has become known in our house.

I have kept very strictly to the rules and follow my reward meal a couple of hours later with a high- protein meal, although I am hard-

ly hungry and occasionally give this third boring meal a miss altogether.

I have become adept at fiddling my social and eating life round this 'happy hour'. My piece de resistance has been a chocolate fondue evening - masses of fruit and boudoir biscuits dipped into a heart-warming mixture of white Toblerone with double cream and brandy - consumed within the prescribed hour. Not bad for someone on a diet.

Reaction among friends to my latest fad has varied from disbelief to outright hilarity. This has not stopped me. Have I lost any weight? After two weeks I had lost a pound and thought I was on course for the steady weight loss they had promised.

Four weeks on, I have not budged an ounce, nor, amazingly have I gained weight. Disappointing though this may be, the enjoyment that I get out of my 'happy hour' far surpasses any thought of weight loss and if I can remain at my current weight, then maybe it is worth continuing.

I rarely feel hungry, have no inclination to nibble, and though I am convinced that this diet, or at least the way I have chosen to follow it, cannot be of much benefit nutritionally, I'm carrying on. I am having so much fun.

'The Carbohydrate Addict's Diet' by Dr Rachael F Heller and Dr Richard F Heller, Mandarin, pounds 4.99.