JORDAN has done it, Sarah Jessica Parker has done it and Drew Barrymore is reported to have done it. Now I have done it.

Over the past week, probably for the first time since I was in nappies, I went a whole five days without eating solid food.

From Monday morning to Friday night nothing passed my lips but a daily, carefully formulated range of fruit juices - no alcohol, no tea or coffee and no chocolate.

The Seven-pounds-in-seven-days-diet (also known as the celebrity juice diet) is supposed give your body a mega-boost of vitamins and all manner of other natural health-giving substances.

The dramatic results are achieved by drinking what are called five “uber juices” at specific points of the day. Of these, two will contain a shot each of wheatgrass and spirulina (a kind of nutrient-packed pond weed), as well as avocado, pineapple, cucumber and apple.

They are the most unappetising shade of dark green but taste surprisingly good.

My favourite was the one made from lemon, carrots and ginger, which had a real kick to it, and there was also the deep purple beetroot-based juice with its epic list of ingredients, comprising beetroot, courgette, lemon, ginger broccoli, cucumber, spinach, celery and carrot.

The course was devised by the Juicemaster, aka Jason Vale, juicer to the stars. He promises that you will not only lose weight, but also have higher energy levels, clearer skin and be “set free from the dieting trap forever”.

So at the end of day five how did I feel, and had I lost any weight? I’ll tell you later - first let me explain how it works.

I collected my juices every morning from Xing in York’s Shambles, which runs a three-day, five-day and full seven-day version of the course. It was Monday morning and the last thing I had eaten was a scone at my mother’s house the previous evening.

The first juice, which was the one with wheatgrass and spirulina, I had in the shop at about 9am. The remaining four for the rest of the day were given to me in flasks, each marked with the time I had to drink them.

Usually on a morning I would have coffee more or less on arrival at work. I had to get out of that habit and that proved to be one of the main problems.

It wasn’t that the juices left me hungry throughout the day or that they didn’t taste good; the hardest part was not giving in to the temptations.

The course makes you very aware of all the times during a day that you would have a coffee, or bag of crisps, or a bar of chocolate without thinking.

Simon Long, co-founder of Xing, said: “There’s a difference between craving and hunger. A lot of people want to eat something but with things like sugar it’s an addiction.

“I was often drinking coffee, but after I had done the course I didn’t really want coffee and I didn’t want sugar.”

I was warned by Simon that when I started the course I might feel a bit groggy on the second day as all the caffeine and other bad things in my system were flushed out. It actually hit me in the late afternoon of the first day with what I can only describe as feeling like a moderate hangover.

I had a queasy stomach, a headache and all I wanted to do was lay down. This may have been down to not drinking enough water, which I was advised to do.

By the end of the second day, and keeping my water levels topped up I was feeling normal. By the third day I was feeling good. The main difference I noticed was the ease with which I could get up on a morning.

No longer feeling sluggish as I walked to walk, I still craved caffeine, but I seemed to have a lot more energy without it.

I admit it wasn’t easy. I had picked the coldest week of the winter so far and, to be honest, I was daydreaming about bacon sandwiches and chocolate by day three. In fact the last thing you want when you have walked home from work in sub-zero temperatures, snow and ice, is a glass of beetroot-based juice to warm your bones.

Yes it was difficult - but not that difficult. I was determined and I stuck to it, promising myself a nice lunch after the all-important weighing which I had planned for Saturday morning.

When I walked into Xing the previous Monday morning I weighed 16 stone 3lb and had a body fat percentage of 27.6 per cent. When I stepped on the scales the following Saturday I weighed 15 stone 11lb – that’s six pounds lighter – while the percentage of blubber in my body had gone down to 24.2 per cent. My BMI had also fallen, from 29.8 to 28.8.

The thing is, I managed to lose almost half a stone in five days and all without doing any exercise. Simon told me the best result he had heard of was three people who lost a stone on the seven-day course, but they were going to the gym too.

In fact the only reason I didn’t go out running (my exercise of choice) was because the pavements were a sheet of ice. I’m pretty sure if I had been more active I would have lost more than half a stone.

And I know what you are thinking: I’m going to fall back into my old ways and put it all back on again.

But I haven’t. My celebratory lunch on Saturday turned out to be a grilled chicken and vegetable skewer with houmous and a glass of cranberry juice.

Breakfast now consists of fruit and natural low-fat yoghurt and I have had two coffees in the past week, where once I was a five-cups-a-day man.

I don’t want to undo all the good work I have done during the week, but the other thing is I am now far more aware of how much rubbish I was putting into my body every day.

So was it worth it? Of course it was; the figures speak for themselves.

Oh, and by the way, the answer to the question that you are all wondering is – everything was just as it usually was, but I didn’t need to go anywhere near as frequently.