Many nutritionists are unqualified fakes who could be putting individuals at significant risk, according to a report in the UK's Sunday Times newspaper.
British consumers are increasingly health conscious, and many regularly visit a nutritionist for advice on how to eat more healthily. But in many cases the advice they are given is not only wrong, it is sometimes fatal.
Catherine Collins, chief dietician at St George's Hospital in London, told the paper she had seen a sharp increase in the number of cases referred to her after a visit to a 'nutritionist'.
"A woman with irritable bowel syndrome (IBS) had been recommended a dangerously restrictive diet and an expensive course of useless supplements. It was putting her health at serious risk."
The problem is that under UK law, anyone can call themselves a nutritionist, a dietician or a nutrition therapist. There are courses available offering a certificate after just one day of study, and many of these fake practitioners are charging exorbitant sums for dispensing potentially fatal advice.
The paper cited a recent survey for the Consumers' Association which showed that only one of 14 unregistered but practising nutritionists had suggested that a patient with a serious bowel complaint visit their GP first.
Both the British Dietetic Association (BDA) and the Nutrition Society (NS) have urged consumers to avoid any nutritionist who is not registered with one of the two organisations.
"Only a state-registered dietician (SRD) has been clinically trained and will have completed either a four-year degree in dietetics or a science degree followed by a two-year postgraduate qualification," Dr Wendy Doyle of the BDA told the paper.
"Along with public-health nutritionists registered with the NS, they must adhere to ethical standards and work within a legal framework. Beyond them, the profession is hopelessly regulated. It is untrue to say that all nutrition therapists lack knowledge and experience, but all too often, people who need help are being given false hopes at a high cost to their health and their pocket."