PARIS • People, it seems, have never been so afraid of their food - and an obsession with healthy eating may paradoxically be endangering lives, say some experts.

Frenchwoman Sabrina Debusquat, 29, recounts how, over 18 months, she became a vegetarian, then a vegan, then a "raw foodist" who avoided all cooked foods, before she ultimately decided to eat just fruit.

It was only when her deeply worried boyfriend found clumps of her hair in the bathroom sink and confronted her with the evidence that she realised she was on a downward spiral.

"I thought I held the truth to food and health, which would allow me to live as long as possible," she said. "I wanted to get to some kind of pure state. In the end, my body overruled my mind."

For some specialists, the problem is a modern eating disorder called orthorexia nervosa.

Someone suffering from it is "imprisoned by a range of rules which they impose on themselves", said Professor Patrick Denoux of intercultural psychology at the University of Toulouse-Jean Jaures.

These strict self-enforced laws isolate the individual from social food gatherings and, in extreme cases, can also endanger health.

Nutritionist Sophie Ortega said she had a patient who was going blind due to a deficiency in vitamin B12, which is needed to make red-blood cells. B12 is not made by the body and most people get what they need from animal-derived foods such as eggs, dairy products, meat or fish, or from supplements.

"A pure, unbending vegan", her patient even refused to take the supplements, she added. "It was as if she preferred to lose her sight... rather than betray her commitment to animals."

The term orthorexia nervosa was coined in the 1990s by then alternative medicine practitioner Steven Bratman, a San Francisco-based physician.

To be clear, it is not an interest in healthy eating - it is when enthusiasm becomes a pathological obsession, which leads to social isolation, psychological disturbance and even physical harm. In other words, as Bratman said in a co-authored book in 2000, it is "a disease disguised as a virtue".

But as is often the case with disorders that may have complex psychological causes, there is a strong debate about whether the condition really exists. The term is trending in Western societies, prompting some experts to wonder whether it is being fanned by "cyberchondria" - self-diagnosis on the Internet.

Orthorexia is not part of the Diagnostic and Statistical Manual of Mental Disorders set down by mental health professionals in the United States. The fifth edition of the manual, published in 2013, includes anorexia nervosa and bulimia nervosa, but not orthorexia.

"The term orthorexia was proposed as a commonly used term, but it is not medically recognised," said Dr Pierre Dechelotte, head of nutrition at Rouen University Hospital in northern France and head of a research unit investigating the link between the brain and the intestines in food behaviour.

Even so, he said, it has a home in the family of "restrictive foodrelated disorders - but it's not on the radar screen".

Psychiatrist Alain Perroud, who has worked in France and Switzerland over the course of a 30-year career, said orthorexia "is much closer to a phobia" than a food disorder.

As with other phobias, it may be tackled by cognitive behavioural therapy - talking about incorrect or excessive beliefs, dealing with anxiety-provoking situations and using relaxation techniques and other methods to tackle anxiety, he suggested.

Outside the world of clinicians, orthorexia seems to be creeping into wider usage.

American blogger Jordan Younger has helped popularise the term, documenting her own painful downward spiral - since reversed - into unhealthy living. On her blog, she describes it as "a bubble of restriction", obsessing over a diet that was "entirely vegan, entirely plant-based, entirely gluten-free, oil-free, refined sugar-free, flour-free, dressing/sauce-free, etc".

Those who seem to be most worried about healthy food are often concerned about food scandals, Dr Pascale Hebel from the Paris-based Credoc research centre said.

Over nearly three decades, Europe has experienced a string of food safety scandals - beginning with mad-cow disease and continuing recently with insecticidecontaminated eggs - as well as mounting opposition to the use of antibiotics, genetically modified foods and corporate farming practices.

The disorder reflects a craving for control, suggested Prof Denoux. Food is seen as a form of medicine to fix a Western lifestyle that may be seen as toxic.

"We are living through a time of change in our food culture, which has led us to fundamentally doubt what we are eating," he said.

Among believers, this "suspicion of being poisoned is deemed proof of insight".

AGENCE FRANCE-PRESSE