Healthy eaters who swear by "clean" foods could be the victims of a dangerous eating disorder that can lead to malnutrition and death.
Insisting on eating "naked" or raw ingredients and diets that ban processed or refined food may lead to symptoms of a condition called "orthorexia nervosa."
Unlike anorexia, where sufferers restrict the quantity they eat, those with orthorexia fixate on quality and strict internal rules.
But the rigid guidelines - which can even exclude entire food groups - can easily result in lethargy, weight loss and dangerous levels of malnutrition while sufferers labour under the misguided belief they are leading healthier lifestyles. Food blogs promoting the latest fad diets and photo-sharing sites such as Instagram have been blamed for condition's rise, as well as eccentric diets promoted by celebrities.
Singer Beyonce is reportedly a fan of a diet that involves surviving on nothing but drinks laced with maple syrup.
One sufferer, the popular New York health-food blogger Jordan Younger, confessed she started to refer to culinary staples such as eggs as "fear foods."
Miss Younger, who has shifted to a more balanced diet, told the Independent: "I had developed many fears surrounding food. I was becoming more and more limited in what I was comfortable eating. I even joked about it with friends, calling certain foods, like eggs, 'fear foods' because I had stayed away from them for so long.
"It was easy to hide behind the shield of veganism when I was at a restaurant with friends or even grocery shopping for myself.
"Anything not clean, oil-free, sugar-free, gluten-free and plant-based I dismissed because it wasn't within my dietary label."
It has been suggested that the controversial condition may be linked to obsessive-compulsive disorder, which has a similar emphasis on control and ritual.
TV presenter Carrie Armstrong, from Newcastle, said she had developed the food phobia when recovering from a serious illness that left her unable to walk.
"You get a physical high from restriction - I was craving purity. I cut out meat, then dairy," she said. "I went vegan, but I wasn't seeing the miraculous results I'd expected. I switched to a raw food diet, then just fruit.
"By the end I was only eating organic melon. I was six stone, my teeth were crumbling and my hair was falling out."
- Daily Mail