[1][2][3] The term was introduced in 1997 by American physician Steven Bratman, who suggested that some people's dietary restrictions intended to promote health may paradoxically lead to unhealthy consequences, such as social isolation, anxiety, loss of ability to eat in a natural, intuitive manner, reduced interest in the full range of other healthy human activities, and, in rare cases, severe malnutrition or even death.
"[10] While the current research on the causes of orthorexia nervosa is limited, significant evidence supports the idea of associated risk factors.
[16] In 2016, formal criteria for orthorexia were proposed in the peer-reviewed journal Eating Behaviors by Thom Dunn and Steven Bratman.
Obsessive focus on "healthy" eating, as defined by a dietary theory or set of beliefs whose specific details may vary; marked by exaggerated emotional distress in relationship to food choices perceived as unhealthy; weight loss may ensue, but this is conceptualized as an aspect of ideal health rather than as the primary goal.
There are only a few notable scientific works that, in an attempt to explore the breadth and depth of the still vaguely-understood illness, have tried to identify which groups in society are most vulnerable to its onset.
[citation needed] Similarly, in a Portuguese study on nutrition tertiary students,[20] the participants' orthorexic scores (according to the ORTO-15 diagnostic questionnaire[21]) actually decreased as they progressed through their course, as well as the overall risk of developing an eating disorder being an insignificant[weasel words] 4.2 percent.
[22] Most scientific findings tend to agree, however, young adults and adolescents are extremely susceptible to developing eating disorders.
[24] A study that investigated this relationship found that increased use of Instagram correlated between symptoms of ON with no other social media platform having the same effect.
[25] With young adults and adolescents making up the majority of social media users, exposure to this type of content can lead to developing unhealthy behavior.
Following the publication of the book, in 2004 a team of Italian researchers from La Sapienza University of Rome, published the first empirical study attempting to develop a tool to measure the prevalence of orthorexia, known as the ORTO-15.
"[28] Bratman elsewhere clarifies that with a few exceptions, most common theories of healthy eating are followed safely by the majority of their adherents; however, "for some people, going down the path of a restrictive diet in search of health may escalate into dietary perfectionism.
"[30] Although orthorexia is not recognized as a mental disorder by the American Psychiatric Association, and it is not listed in the DSM-5,[31] as of January 2016, four case reports and more than 40 other articles on the subject have been published in a variety of peer-reviewed journals internationally.
[10] According to a study published in 2011, two-thirds of a sample of 111 Dutch-speaking eating disorder specialists felt they had observed the syndrome in their clinical practice.