Orthorexia: can healthy eating go too far?

02 Sep 2019

Questions and answers on the latest advice, evidence and practice

Annabel Gipp is a specialist community dietitian working in York and North Yorkshire. [email protected]

‘Orthorexia Nervosa’ (ON) is a relatively newly described eating disorder and may not be a familiar term to a lot of health professionals. The term ON was originally proposed and described by Steven Bratman in 1997 in response to the rising numbers of people who were observed to have a fixation on healthy or righteous eating (2 - see references below).

Within medical research, the first peer reviewed article of the disorder was not published until 2004 where an Italian study described ON as ‘maniacal obsession in the pursuit of healthy foods’ (3).

Remaining relatively unknown in the public domain, it has come to light in recent years, mainly through the rise of social media. In 2014, a highly successful blogger named Jordan Young, whose blog was focused on vegan eating, revealed to her 70,000 followers that her drive for healthy eating had become pathological and resulted in her being diagnosed with an eating disorder and subsequent malnutrition.

This prompted a wealth of coverage and interest from many major news channels in the USA, however, the disorder continues to fail to be recognised within diagnostic criteria (3). However, in a study of European eating disorder professionals, over two-thirds were aware of the condition (n=111) despite the lack of formal diagnostic criteria.

Q. What is orthorexia nervosa?

The term comes from the Greek words ‘orthos’ meaning ‘proper’ and ‘orexia’ meaning ‘appetite’. It is a term that has been used to describe an eating disorder where the individual has a rigid and fixed obsession with ‘healthy eating’. This can include fixation on ‘pure’ foods, omitting ‘bad’ foods and an inflexible belief over the expectations and importance of healthy eating. Commonly, those with ON omit things that are ‘unnatural’, ‘processed’ or that have been processed in ways which are believed to reduce the beneficial health properties of the product (1).

Whilst eating habits and the way we choose to eat are not pathological, within ON, the importance and obsessive nature of these habits tend to have a negative impact on everyday life for the individual. This causes physical, mental and social difficulties, leading it to be classed as an eating disorder (2).

There is currently no clinical consensus within literature on the classification of ON; whether this is an eating disorder at all, if it is a new type of eating disorder or if it is a varying presentation of another eating disorder, for example anorexia nervosa. Despite this, reports of orthorectic behaviours are common and individuals often lack the cognitions associated with either anorexia nervosa or bulimia nervosa, which seems to therefore support the line of thinking that this is a new type of eating disorder that is being identified (7).

Q. What are the signs and symptoms of orthorexia nervosa?

This is a disorder which is not yet recognised within the ICD10 or DSM-V, so there is not an official list of validated signs and symptoms. However, due to the increasing interest both in popular and academic science with ON, several key themes and symptoms are agreed upon.

A key component of ON is that the individual is not preoccupied with the quantity of the food eaten, but instead of the quality of food eaten. Common behaviours linked with this pre-occupation include: enduring worry and a pre-occupation with eating impure or unhealthy foods and what effect these would have on the body if the individual were to eat them; spending excessive time periods thinking, researching, writing or talking about food; excessive time preparing or acquiring foods which can also lead to financial difficulties due to the types of food being bought; inflexibility or intolerance to other people’s diets and beliefs about food and eating; and feelings of guilt and shame when perceived ‘unhealthy’ foods are eaten.

These food-related behaviours can also lead to malnutrition due to the imbalance of the diet consumed and also difficulties with activities of daily living such as education, socialisation or work. It is important to distinguish between ON and other psychiatric disorders such as OCD which can sometimes present in similar ways e.g. inflexibility and ritualistic behaviours are common in both conditions, or through behaviours associated with religious, medical or cultural reasons (4).

It has also been suggested that the presence of ON symptoms can be a graded continuum of behaviours, ranging from healthy behaviours and attitudes to pathological difficulties and that at the extreme pathological end of this spectrum, eating behaviours mean that ‘purity’ overcomes pleasure (1).

Q. Is there a cross-over between orthorexia nervosa and anorexia nervosa (AN)?

AN differs from ON due to the fact that those with AN have a reported pre-occupation with body weight, body shape and significant body dissatisfaction that leads to restriction of food quantity in order to manipulate weight.

Those with ON do not share this body dissatisfaction and instead manipulate their diet due to an obsessive compulsion to achieve the perfect ‘healthy’ diet. However, some of the symptoms commonly associated with AN can be observed in ON, including weight loss, dietary restriction of certain foods e.g. high fat foods and inflexibility around eating.

Most commonly, those who present with ON within eating disorder services, are diagnosed with Avoidant or Restrictive Food Intake Disorder (ARFID) rather than AN or bulimia nervosa (BN). The ARFID condition can be a large heterogeneous group covering many atypical presentations of eating disorder, however those with ON do not share some of the key signs and symptoms which are common in others with ARFID.

This includes restricting intake based on a disinterest in food, restricting due to the sensory properties of foods or due to a traumatic event (3). ARFID could possibly be sub-divided into smaller, more specific subgroups. The benefit of this would be the ability to provide more tailored and specific treatment options and associated improved outcomes (4).

There is also evidence to suggest that ON behaviours are common co-morbid features within other eating disorders. Research has shown that in 28% of patients with confirmed AN or BN, ON is also a co-morbid condition at the start of treatment.

Interestingly this rises to 53% after treatment. This may indicate that ON could be a residual symptom of recovered eating disorder or even a ‘less severe’ form of AN. However, within research it has been suggested that residual ON symptoms need to be investigated within these patients as they have been identified as one cause of relapse and recurrent eating disorders post-treatment (5).

Q. Is it true that dietitians and nutritionists are commonly diagnosed with this eating disorder?

The onset of ON is thought to be related to increased thinking about food choice, weight and shape, all of which could be linked with the work of a dietitian. An increased prevalence of eating disorders has been noted in nutrition professionals.

Dietitians score, on average, more highly on eating disorder screening questionnaires. This is replicated when using screening tools for ON. In one study, of 636 dietitians from the US, it was found that 49.5% of respondents self-reported symptoms of ON and 12.9% for other eating disorders, which would suggest that ON could be more common in dietitians (6). 

In general, ON has been found at low rates in the general population, with less than 1% predicted to show signs of the disorder. However, increases in prevalence are found in pockets of the population, including dietitians, but also nutrition students, yoga instructors and exercise students, all of whom are trained to review food and eating as part of their practice.

Additionally, research has found that use of Instagram is associated with increased reports of ON behaviours, which was not replicated with other social media channels such as Pinterest, Facebook, Twitter or Linkedin.

This was linked to the image based nature of Instagram and the selective exposure of images that are seen as normalising behaviours which are actually not ‘normal’ or healthy. Eminence-based practice, where celebrities or popular users promote behaviours, may also hold some influence in promoting orthorexia, due to the high following of these accounts adding credibility to their claims (8).

Q. Is there a screening tool or questionnaire for orthorexia nervosa?

The ORTO-15 test is the most commonly used measure for detecting signs and symptoms of ON. It is a 15 item Likert scale test in which the respondent needs to answer ‘always’, ‘often’, ‘sometimes’ or ‘never’. The scale is then scored 1 to 4, with 1 being indicative of orthorexia behaviour and 4 for normal eating behaviour. The cut-off score for suspected ON is usually 40 points. This tool has been reported to have a sensitivity of 100%, specificity of 73.6%, positive predictive value of 17.6% and negative predictive value of 100% (7).

The tool has been identified in having some psychometric limitations, including lack of standardisation and cross-cultural variation, with relatively little work done to establish differential item functioning between different cultures. There are also concerns that the high cut-off score may lead to high false positive rates and therefore it is unsuitable for a diagnostic tool (8).

Key points

1. Orthorexia nervosa is a relatively new disorder which centres around the individual’s obsession with ‘clean’ and ‘healthy’ eating to the point where the diet is highly restrictive and obsessional.

2. This disorder is more prevalent in those working in the fields of nutrition and exercise.

3. The ORTO-15 is a screening tool that is designed to identify orthorexia behaviours, but its use is limited due to lack of robust validation.




  1. Koven N S & Senbonmatsu R (2013) A neuropsychological evaluation of orthorexia nervosa. Journal of Psychiatry 3: 214-222
  2. Chaki B, Pal S & Bandyopadhyay A (2013) Exploring scientific legitimacy of orthorexia nervosa: a newly emerging eating disorder. Journal of Human Sport and Exercise 8(4): 1045-1053
  3. Dunn T M & Bratman S (2016) On orthorexia: A review of the literature and proposed diagnostic criteria. Eating Behaviours 21: 11-17
  4. Moroze R M, Dunn T M, Holland J C, Yager J & Weintraub P (2015) Microthinking about micronutrients: A case of transition from obsessions about healthy eating to near-fatal “orthorexia nervosa” and proposed diagnostic criteria. Psychosomatics 56(4): 397-403
  5. Segura-Garcia C, Ramacciotti C, Rania M, Aloi M, Carolea M, Bruni A, Gazzarrini D, Sinopoli F & De Fazio P (2014) The prevalence of orthorexia nervosa among eating disorder. Eat Weight Disord 20: 161-166
  6. Tremelling K, Sandon L, Vega G L & McAdams C J (2017) Orthorexia nervosa and eating disorder symptoms in dietitians in the United States. K Acad Nutr Diet 117(10): 1612-1617
  7. Gramaglia C, Brytek-Matera A, Rogoza R & Zeppegno P (2017) Orthorexia and anorexia nervosa: two distinct phenomena? A cross-cultural comparison of orthorexia behaviours in clinical and non-clinical samples. BMC Psychiatry 17: 75
  8. ITurner P G & Lefevre C E (2017) Instagram use is linked to increased symptoms of orthorexia nervosa. Eat Weight Disord 22: 277-284