IF YOU want a rabbi to live with you for a week or so, at a charge of £1,000 plus expenses for seven days, Rabbi Martin Felt is your man. In America, the personal nutritionist has replaced the fitness trainer as the ultimate status symbol, and Madonna, Cher and Michael Jackson take theirs on tour. Now Martin, a 40-year-old American kabbalistic rabbi turned nutritionist, has brought the practice to London.

Frequently he lives with clients, whether individuals or families, for two intensive weeks. Sometimes he goes on holiday or business trips with them, as far afield as Los Angeles. Other times he flies to Bahrain or Kuwait to offer advice or rejuvenation programmes.

Martin is, for example, live-in personal nutritionist to businessman Avi Nissanni and his family in Hampstead. ‘I’ve lived with them for a week or two four times in the last six months. I’ve changed his body chemistry, massaged them, cooked for them, taught his family how to prepare food, looked after his wife, exercised with them, and taught them how to stretch, breathe and meditate.’ Martin, who is soon to accompany the family on a trip to America, has two dozen such ‘very wealthy’ private clients. Many of his clients (‘mostly women from SW1 and SW3′) simply lack a feeling of general well-being. Others suffer from chronic tiredness, anxiety or depression. But he specialises in degenerative diseases, and has worked extensively with cancer, arthritis and Aids. He believes food is the best medicine.

He has just published a book, Eat Yourself Fit with the Felt Formula, to help you ‘discover the food plan to change your life’, and promising immediate and extraordinary results. A questionnaire helps you interpret your symptoms and find your individual Felt formula for eating, to bring your body back into balance. But he prefers to meet clients, preferably for four hour-and-a-half consultations, at a cost of £70 each. ‘I’ve seen hundreds of thousands of people over the years,’ he claims.

He came to Britain eight years ago to escape American health radicalism. He doesn’t believe in extreme diets or megadoses of vitamins, smokes ‘10 cigars a year and the occasional cigarette’, and eats his share of junk food. ‘I’m not a phoney food faddist.’

He sees outpatients in his one-bedroom, student digs-style flat, with posters of Indian deities on the wall, amid the alternative books and dirty crockery in the kitchen. He diagnoses with a conventional blood test (£59) and extensive questions. ‘Have you had any infection over the last few weeks? Any specific pain? Any gas, belching or flatulence? Are you short-fused, irritable or volatile?’ He is efficient and his diagnosis very precise.

He tells me not to mix proteins and carbohydrates (to aid digestion), cut down on acid-forming foods (the body stores toxins, which acid exacerbates), not to eat bread (yeast ferments in the stomach), and to take Solgar and BioCare supplements (food capsules represent a third of his treatment). MARTIN is dressed in dark colours, and has an intense face and curly hair. He’s extremely knowledgeable but weird and controlling. He talks, sometimes with his hands in the air, with his loud voice rising, saying things like: ‘You have the institutionalisation of the mythological basis of a culture anthropologically manifested in a country with a psychic nature phenomena.’ The phone rings incessantly and he talks at leisure: ‘Not a disturbance, nice to hear from you…’

His method is a sensible integration of Western and Eastern medicine. Later I followed some of his advice and found it made a positive difference. Atmospheric pollution and stress, he says, affect the chemical balances of our bodies, changing the genetic basis of health: everything is bio-chemical; most physical and mental ailments can be attributed to the food we eat; and eating yourself fit, alert and energetic, and to the correct body weight, is simply a matter of knowing what to eat and when. ‘The foods fuelling the body must be accurately and metabolically precise for whatever disease or stress imbalance is going on.’

Martin was brought up in Philadelphia where his father sold insurance and his mother was a university administrator; a ‘just above working-class’ family. He gained a degree in law, political science and history. Thereafter, none of his dietary research was carried out in an institution or university.

His system, which has taken 10 years to develop, stems from his training with his ‘mentor’ Dr Kaushik, an Indian medical doctor, ‘a Hindu and Buddhist’, who taught him Ayurvedic and Chinese medicine, meditation, homeopathy and yoga. ‘I lived and studied with this man for six years in the Seventies.’

In addition, he’s studied herbalism, re-birthing, clinical nutrition, naturopathy, and body work from osteopathy to Rolfing. ‘I experienced all these things myself.’ There is, he says, nothing wrong with being a jack of all trades.

His work culminated in 1987 in a doctorate of divinity at Shiloh seminary in America, where he studied mysticism and the link between science and spirituality. He calls himself an ordained kabbalistic ‘rabbi’, ‘an esoteric and non-pulpit position’. This isn’t a rabbinical ordination recognised by Orthodox Jews, who compare it to a divinity graduate calling himself a ‘mystical vicar’.

Martin has three young children, all living abroad, by three different women. He’s not married to any of them, has already been married twice and supports the children. ‘My work has always been a priority.’ What’s he like? ‘I’m tempestuous, volatile, cataclysmic and mercurial.’ Can’t he transform himself with his food? ‘I am. Things don’t change overnight.’ Aren’t things meant to change radically and swiftly? ‘On different levels. I’m not holding myself up as a guru.’