GPs must remain the first port of call for anyone worried about their health, according to a report by Which? that warns nutritional therapists are 'gambling' with patients' health. Which? is taking its findings to the government and demanding proper regulation in this sector.

It sent undercover researchers posing as patients with a range of health problems to 15 consultations with nutritional therapists. The advice given was assessed by an expert panel which included a GP.

Six of the visits were rated as ‘dangerous fails’, a further eight were rated as ‘fails’, and only one was deemed a ‘borderline pass’.

A researcher posing as a breast cancer sufferer was told to delay radiotherapy treatment recommended by an oncologist because the nutritional therapist said they could rid the body of cancer through diet.

She was advised to follow a no-sugar diet for three to six months saying ‘cancer feeds off sugar'. She added: 'By cutting out sugar we have a better chance of the cancer going away.'

The expert panel deemed this highly irresponsible and incorrect advice.

Another member of the investigation team was told that if the course of treatment prescribed for severe tiredness started to make him feel unwell, it showed the ‘treatment was working’ and he shouldn’t contact his GP as they ‘wouldn’t understand what was happening’.

Which? executive director, Richard Lloyd, said the investigation had found ‘some shocking examples of irresponsible advice given by nutritional therapists’.

‘Our research shows that not only were they a waste of money, but some of their recommendations could seriously harm people’s health,’ he said. ‘This is largely a self-regulated industry where anyone can set up and practice as a nutritional therapist, meaning there is no real protection for consumers.’

‘Which? wants the government to take action to stop nutritional therapists putting people’s health at risk,’ he added.

A spokeswoman for the British Association for Applied Nutrition and Nutritional Therapy (BANT), a UK-wide body representing over 2,400 nutritional therapy practitioners, said the association agreed that practitioners should come under statutory regulation.

‘BANT would welcome the opportunity to discuss the future of nutritional therapy regulation to further develop safe and effective practice,’ she said.

‘As the professional body for nutritional therapists, BANT is dedicated to the advancement of nutrition science and the safe, evidence-informed practice of nutritional therapy.

‘Instilling public confidence and offering consumer protection is of primary importance to BANT. BANT members are bound by a strict code of ethics designed to protect patient interests and procedures are in place to deal with any complaint brought against a BANT member.’