The disciples of Dr Joshi

He's the latest diet guru to the stars, from Gwynnie to Cate. But is he doing them any good?

He is the ultimate lifestyle guru. His client roster reads like a celebrity agent's address book. Nish Joshi's detox and lifestyle books have stormed into the Amazon charts and his clinic in central London charges thousands of pounds for a three-week programme. But health experts say his methods could cause more harm than good.

Step inside Dr Joshi's well-appointed clinic in London and you follow in the footsteps of Gwyneth Paltrow, Nicole Appleton, Cate Blanchett (pictured right), Sadie Frost, Kate Moss, Patsy Kensit, Ralph Fiennes and Rupert Everett.

Dr Joshi, who studied medicine in Mumbai but is not registered with the General Medical Council to practise in the UK, has devised a 24-day detox, involving diet, supplements and alternative therapy.

For six weeks clients eat a non-dairy, wheat-free, gluten-free diet banning all alcohol, sugar, tea, coffee, red meat and even fruit (except bananas). Instead clients are steered towards a restricted diet of cereals, salads, steamed vegetables, and fish (excluding tuna, swordfish and shellfish).

In addition Dr Joshi prescribes his own assortment of herbal supplements and uses a technique called "cupping", used in Egyptian and Chinese medicine for thousands of years. It gained celebrity kudos when Paltrow was snapped with its characteristic round welts on her back. Clients also undergo two colonic irrigations and weekly sessions of reflexology.

The effect of Dr Joshi's work has inspired gushing celebrity endorsement. Patsy Kensit describes him as "a miracle worker". Sadie Frost is equally effusive: "You completely trust yourself with Joshi. He's an amazing man." Paltrow declares: "Joshi is truly special. I love him."

Useful as such endorsements are, his clients have a more tangible value. Most fork out £3,150 for the first consultation, £375 per week for subsequent consultations, £385 per colonic irrigation and £3,417.60 for six weeks' worth of diet supplements.

But nutritional experts question Dr Joshi's methods, describing some of his ideas, bluntly, as rubbish. Rick Wilson, director of nutrition and dietetics at King's College Hospital in London, yesterday expressed grave concerns about the programme.

Mr Wilson believes that, in creating his intensive course, Dr Joshi has taken "tiny fragments of science which he has interpreted way beyond what most people in the field would say could be substantiated". All in all, he concludes, the detox is "not healthful".

He doubted the validity of such a severe diet, pointing out that yeast, bread and wheat are not toxic.

Mr Wilson also believes that Dr Joshi's super liver cleanse (retailing at £324.50 for a two-week supply) is nothing more than a dose of multivitamins. The health guru claims it is "a herbal formula of nutrients which work together to support and maintain the liver in optimum condition".

But Mr Wilson said: "This looks very like a multivitamin supplement which can be obtained very cheaply from Sainsbury's, Tesco or Morrisons - about £32 for one month's supply. If someone were following Dr Joshi's very restrictive diet they would need these to put back all the nutrients the diet cuts out."

But Dr Joshi rejected the criticisms: "This diet is not meant to be continued for the whole of your life. It's not something to deal with all nutritional complaints. Patients and nutritionists need to understand that food has a lot of chemicals in it.

"By changing what you are eating you can change the body's functioning. Other diets like the Atkins diet concentrate on losing weight, but this changes the way your metabolism is working.

"If this nutritionist [Mr Wilson] could please ask himself, why is it that so many people in this country are obese, why is it that people are so confused about what they should or should not be eating."

Detox Test: The highs and lows of the Joshi regime

After a bit of a wait in a candlelit reception, Dr Joshi, above, takes me up to his office, where he flicks through a form about my health. He quickly weighs me, peers at my tongue, takes my blood pressure and pulse and, before I know it, I'm lying down with six heated cups on my back.

A brief chat about pH balance in the body and the cups are off. I'm marched downstairs, handed my supplements and off I go. But will I be able to survive without my morning coffee?

During week one I suffer from raging headaches. (According to Dr Joshi it's the sugar leaving my body.) I have to force down the pills and feel resentful munching on celery, grilled fish or chicken and piles of steamed vegetables. On the third day my headaches are so severe I go to bed at 7pm - anything to avoid the aching. The headaches pass by week two.

I start to dread social events; one weekend I go to a wedding and a christening. Both events serve lamb, cake and endless bottles of champagne. By the fourth week I am seriously lacking in energy. My weekly gym sessions have been dumped in favour of a gentle swim. I hardly have the strength to lift my cups of herbal tea, let alone weights.

But on the plus side, I have no desire to eat anything sweet. I assume the acupuncture needles in my ears (to end sugar cravings) must be working.

The "free from" section in the supermarket is no longer an aisle to skip past: it is now my main source of food. I re-educate myself about diet. I throw away the ketchup in my cupboard, no longer miss coffee and enjoy discovering a variety of fresh fish. Not surprisingly I lose more than a stone in six weeks and go down a dress size.