By Johanna Fee,
Orthorexia nervosa is an eating behavior. It is an obsession of eating only foods deemed ‘biologically pure’ or ‘healthy’. It includes severe limitation of diet, coupled with obsessive thoughts about food consumption, and can lead to social isolation.  This issue may be augmented by current trends in health and diet such as veganism, paleo, non-GMO, and raw-food diets.
Currently being debated, is whether orthorexia nervosa should be classified as an eating or behaviour disorder.  Unlike other eating disorders it does not include obsession with the amount of food consumed rather the quality. Orthorexia nervosa has qualities attributing to both behavioural and eating disorders.
An emotional and behavioural disorder is characterized by a consistent and repeated behaviour, the inability to maintain social relationships, and displays of depression/unhappiness, all of which cannot be explained by intellectual, health, and sensory factors.  Orthorexia nervosa could be classified as a behavioural disorder as the compulsion to eat only ‘healthy’ food is a repeated behaviour that affects the person’s ability to interact with others in normal social occasions involving food. The lack of social interaction can result in displays of depression. The Diagnostic and Statistical Manual of Mental Disorders 5 (DSM) diagnosis of obsessive compulsive disorder (OCD) states that obsessions consume more than 1 hour of the day and can impair social interactions.  With orthorexia nervosa the compulsion to eat only food deemed ‘pure’ and ‘healthy’ can take hours of planning and preparing the foods making it an obsession.
However, it can also be argued that because orthorexia nervosa includes the restriction of food, in quality rather than quantity, it should be diagnosed as an eating disorder. While it is not currently recognized as a disorder in the DSM 5 , patients presenting with behaviours associated with orthorexia nervosa may fit into several categories of eating disorders currently recognized: avoidant/restrictive food intake disorder (ARFID), or unspecified feeding or eating disorder (UFED). UFED is the category used to describe eating/feeding behaviours that cause issues in functioning but do not fully meet the criteria of other disorders.  Orthorexia nervosa does not fit the model for other disorders such as anorexia or bulimia because it does not involve a restriction in the quantity of food and is not associated with body-image issues.  ARFID presents as sustained failed to acquire sufficient nutritional and/or energy requirements that are not associated with a disturbance of perception of body shape or size.  It is associated with significant weight loss, nutritional deficiencies, required use of oral supplements, or issues with psychosocial functioning. Orthorexia Nervosa cases may be able to meet these criteria as restriction of types of food eaten can lead to failure to acquire required nutrients such as iron or vitamin B12 commonly seen in restrictive vegetarian or vegan diets.
The psychosocial effects of Orthorexia Nervosa are common to both eating and behaviour disorders. Orthorexia Nervosa can cause psychosocial issues as obsession with consuming only ‘healthy’ or ‘pure’ food can cause isolation from normal social interactions. The large amount of time spent preparing foods and inability to eat at normal social gatherings results in confinement from interacting with family or friends. Lack of social interaction can lead to isolation and depression. 
Orthorexia nervosa is a serious disorder that lacks recognition in the DSM 5.  Studies done on the subject have been specific to niche groups and areas. Turkey has done studies on prevalence in performance artists and medical doctors. [4,5] Athletes have been found to be a higher risk population for orthorexia nervosa as an eating disordered behaviour as they often self-impose rigid diets to improve performance without consulting a sports nutritionist or dietician.  Large population studies need to be done on orthorexia nervosa to provide evidence which will allow for recognition and classification within the DSM.
Treatment of orthorexia nervosa is not unlike other eating disorders, it involves dieticians, physicians, and psychotherapists.  With today’s health and diet trends it may be difficult to tell when what is perceived as ‘healthful eating’ has transformed into a disorder. Spending an abnormally large amount of time thinking about or planning what you’re eating (>1hr/day), or avoiding social situations because of what is served isn’t ‘pure’ may be indicators to seek help. Healthy and mindful eating is important but consulting a dietician or physician is advisable for those concerned that their eating habits have become obsessive or too restrictive.
 Brytek-Matera A. Orthorexia nervosa – an eating disorder, obsessive-compulsive disorder or disturbed eating habit? Archives of Psychiatry and Psychotherapy. 2012;1:55-60.
 Emotional and Behavioral Disorder. Georgia Department of Education.
 American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 2013;5.
 Bosi A, Camur D, Gueler C. Prevalence of orthorexia nervosa in resident medical doctors in the faculty of medicine. Appetite. 2007;49(3):661-666.
 Aksoydan E, Camci N. Prevalence of orthorexia nervosa among Turkish performance artists. Eating and Weight Disorders-Studies on Anorexia Bulimia and Obesity. 2009;14:33-37.
 Segura-Garcia C, Papaianni M, Caglioti F, et al. Orthorexia nervosa: A frequent eating disordered behaviour in athletes. Eating and weight disorders. 2012;17(4):E226-E233.