The summer Kaila Prins turned 13, she started breaking out in hives all over her body. Her mother remembered that when she was a baby she had tested allergic to soy, so encouraged Prins to cut that out of her diet, bringing her attention to ingredients for the first time. Prins had never paid much attention to what she ate, enjoying the occasional McDonald’s meal or a few chunks of cookie dough like many other teens. But what began as an allergy-related need to pay attention to food labels slowly turned into an obsession that took a toll on the young girl’s health.

A self-described perfectionist, Prins took label reading seriously. She decided to get healthy while cutting out soy. She began by cutting out excessive fat and added sugar, which soon morphed into eating only whole wheat bread, peanut butter, fruit and salad. By the end of the summer, at 5ft 4in (162.6cm), her weight had dropped to 97lbs (43.9kg).

Initially, relatives didn’t seem worried about her physique, but instead applauded her healthy eating habits. “A family member who never complimented me before told me how good I looked,” says Prins.

But as Prins got older, her healthy eating, coupled with increasing amounts of exercise, began to dictate her life. By high school, she was captain of the cross country team. By college, she was biking for six miles a day on top of an hour or more at the gym.

After college, she began religiously following all the eating rules in Oxygen Magazine, a publication devoted to “clean eating” for female bodybuilders. She started working out with a personal trainer to compete in bodybuilding figure competitions. As her obsession with healthy food escalated, she became a vegan, which caused her to break out in acne so bad that she felt ashamed to go to work. She stopped menstruating. And still she thought she was healthy. She got certified as a personal trainer.

“When I was at the gym I wore a sports bra, and other women would tell me that I looked amazing and asked me how they can look like me,” Prins remembers.

But inside, Prins was miserable. She remembers going on a date with a guy that took her to a gourmet pizza place and then the theater. She ate her slice and spent the entire play unable to focus on the stage, ruminating about how “unclean” she was for eating that one slice of pizza. She did not let the guy kiss her goodnight because of how “unworthy” she felt. Instead, she had a panic attack, ran to a 24-hour diner and bought a huge brownie. She forced herself to eat the whole thing as a sort of punishment for being “unclean”.

Prins was becoming depressed, even suicidal. A former star student, she had enrolled in a master’s program at Columbia University, but after her first semester she was in danger of failing. With all her thoughts on what to eat and how much to exercise, she could not focus on her studies. She left Columbia after one year. She tried therapy, only to drop out when she began arguing with her therapist over whether or not lettuce is a carbohydrate.

Although Prins knew something was wrong, she did not find a name for it until she stumbled upon a book on orthorexia nervosa by Dr Steven Bratman. Bratman first coined the term in 1997 for a pattern of healthy eating that crosses over into eating disorder territory. “Ortho” means right or correct, and “rexia” means desire. In other words, a desire to be correct. Prins finally knew what was wrong with her.

Distinct from other eating disorders, orthorexia is “an unhealthy obsession with otherwise healthy eating”, according to the National Eating Disorders Association. It’s unknown how widespread the condition is because it is not currently recognized as a clinical diagnosis. As awareness of healthy eating grows and more consumers than ever before go vegan and gluten free, clinicians say they are encountering more patients presenting orthorexia symptoms. Now, some health experts are calling for its formal recognition.

Last year, a prominent health food blogger, Jordan Younger, announced to her followers that she was battling orthorexia, making headlines in fitness and lifestyle magazines. Since then, Younger has devoted her blog, and her Instagram account, which has 120,000 followers, to balanced eating and raising awareness of orthorexia.

While Younger has recently published a book about her experience with orthorexia, there is debate in the psychiatric community over a diagnosis. The latest version of the psychiatric diagnostic bible, the Diagnostic and Statistical Manual of Mental Disorders, or the DSM-5, came out in 2013 but did not include orthorexia as a separate diagnosis from anorexia nervosa.

Dr Thomas Dunn, a professor of psychology at the University of Northern Colorado, is one of the few researchers who has been published in peer-reviewed journals on orthorexia. He believes that it should be a separate diagnosis.

Dunn sees the differentiation in the motivation of patients: “People with anorexia restrict their intake by following healthy diet fads to be thin. People with orthorexia restrict their intake by following a healthy diet to be healthy.”

To Dr Angela Guarda, director of the Johns Hopkins Eating Disorders Program, the orthorexia label reminds her of another label from 10 years ago – the female athlete triad. It was a label for women who exercised too much, ate too little and stopped menstruation – all things that happened to Prins.

Eating disorders reflect the culture, says Guarda. “Twenty years ago, many of the patients I saw with anorexia were vegetarians. Now, they also talk about eating exclusively organic food or say that they are lactose intolerant and allergic to gluten, when their blood tests show that they are not. These explanations are convenient ways to hide their fear of eating high calorie foods or foods prepared by others which provokes anxiety.”

The debate in the psychiatric community over a diagnosis of orthorexia is “a bit of a vicious circle” according to Dr Cynthia Bulik, professor of eating disorders at the University of North Carolina at Chapel Hill. “It is not a bona fide diagnosis, so there is no research on it; however, since there is no research on it, we know very little about whether it actually should be a disorder,” she says.

While it’s difficult to gauge the prevalence of orthorexia without a diagnostic code, around 30 million people are estimated to suffer from an eating disorder in the US, according to the National Association of Anorexia Nervosa and Associated Disorders.

These days, most of us probably know at least one person who, in an effort to be healthy, has gone on fad diets, cut out entire food groups or subsisted on juice for days at a time. Supermarket grocery aisles are stocked with gluten free products and soy cheese, while raw food and vegan restaurants seem to pop up every month in a big city. Mintel, a research firm, estimates that sales of gluten free products have increased 63% from 2012 to 2014, despite celiac disease (gluten intolerance) affecting only around 1% of the US population. Meanwhile, vegan cheese sales saw an increase in 22.7% in 2014 over last year, according to natural foods market analyst company Spins.

In our current food-obsessed culture, healthy eating can take on a quality similar to religious fervor, in which certain foods are sinful and eating in a certain rigid way is godly and rewarded, says Sondra Kronberg, a nutritional therapist and spokeswoman for the National Eating Disorders Association.

But it’s a slippery slope from trying to eat right to developing an eating disorder. People start to restrict certain food groups with the best of intentions. “First vegetarian. Then vegan. Then raw, then they run out of things to eat,” says Dunn.

As with anything else, some people are good at moderation, while others fall into an obsessive pattern and let it take over their lives. “Healthy food is better for you, but there is an extreme; everything is toxic in extreme,” says Guarda.

Prins eventually sought professional help from eating disorder specialists and began to recover using a system she calls “discovery” – her name for learning who you are and what you like. She stopped reading blogs on healthy eating and blocked the transformational stories on Facebook.

“I still eat healthy,” Prins told me, “but I don’t Instagram it, I don’t tweet it. I like vegetables, but I also like stand up comedy. I can go work out or I can also go hang with my friends instead.”

Not every eating disorder story has a happy ending. “I just am scared for where the world is going,” Prins says. “We are so obsessed with nutrition, it is hard to distinguish between people who are orthorexic and people who are just health conscious.”

The National Eating Disorders Association has a toll-free, confidential helpline, which can be reached at: 1-800-931-2237. Alternatively, you can visit their website.