What is Orthorexia Nervosa?

Updated: Oct 9, 2020

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Orthorexia is an unhealthy obsession with healthy eating to the point of damaging their well-being. The focus is on quality, not the quantity of food, the purity of food, and it's health benefits. While the end goal of orthorexia is not to lose weight, one risk factor is a past or current eating disorder.

Diagnosis Criteria

All studies reviewed indicates primary diagnostic criteria as:

  • Obsessional or pathological preoccupation with healthy nutrition

  • Emotional consequences (e.g., distress, anxieties) of non-adherence to self-imposed nutritional rules

  • Psychosocial impairments in relevant areas of life as well as malnutrition and weight loss

Definition and diagnostic criteria for orthorexia nervosa: a narrative review of the literature


Credit to NEDA.

  • Compulsive checking of ingredient lists and nutritional labels

  • An increase in concern about the health of ingredients

  • Cutting out an increasing number of food groups (all sugar, all carbs, all dairy, all meat, all animal products)

  • An inability to eat anything but a narrow group of foods that are deemed 'healthy' or 'pure'

  • Unusual interest in the health of what others are eating

  • Spending hours per day thinking about what food might be served at upcoming events

  • Showing high levels of distress when 'safe' or 'healthy' foods aren't available

  • Obsessive following of food and 'healthy lifestyle' blogs on Twitter and Instagram

  • Body image concerns may or may not be present


For the most part, the motivation behind ON is unknown. Research has shown that there isn't one cause connected to every case of orthorexia, but many interchangeable reasons. Not every case is the same. Orthorexia Nervosa is similar to anorexia nervosa; we [PNPCo] speculate that their causes are comparable. Unlike AN, gender and self-esteem are not a factor in the development of ON.

Studies have shown a link between anorexia and serotonin levels. Serotonin is a chemical that affects a variety of psychological and biological factors, including hunger, anxiety, impulsivity, perception, and memory.

Mental Health Disorders. Other mental health disorders can lead to ON. Those disorders include perfectionism, obsessive-compulsive traits, psychopathy, disordered eating, and history of an eating disorder.

Run in Families. Families share not only genetics but also eating habits. Though more research is required, some studies have indicated that eating disorders can be passed down from generation to generation through genetic factors. Parents also pass down their eating habits to their children, so if the parents have a pattern of bulimia, the children will more likely too.

Body Image. People with a negative body image are more likely to develop an eating disorder. A negative body image can develop if a person is influenced by media or wants to live up to societal standards or norms. An adverse body image can lead to frequent dieting and overeating.


Instagram increases the severity of Orthorexia Nervosa.

Turner PG, Lefevre CE. Instagram use is linked to increased symptoms of orthorexia nervosa. Eat Weight Disord. 2017;22(2):277-284. doi:10.1007/s40519-017-0364-2

A 2015 study showed that symptoms overlap between orthorexia and anorexia nervosa, obsessive-compulsive disorder (OCD), obsessive-compulsive personality disorder (OCPD), somatic symptom disorder, illness anxiety disorder, and psychotic spectrum disorders.

Koven NS, Abry AW. The clinical basis of orthorexia nervosa: emerging perspectives. Neuropsychiatr Dis Treat. 2015;11:385-394. Published 2015 Feb 18. doi:10.2147/NDT.S61665

Of 2,500 registered dietitians, 49.5% were at risk for orthorexia nervosa, and 12.9% were at risk for an eating disorder. The group at risk for ON had a lower mean body mass index.

Tremelling K, Sandon L, Vega GL, McAdams CJ. Orthorexia Nervosa and Eating Disorder Symptoms in Registered Dietitian Nutritionists in the United States. J Acad Nutr Diet. 2017;117(10):1612-1617. doi:10.1016/j.jand.2017.05.001

Experts estimated that less than 1% of the US population has orthorexia.

Dunn TM, Gibbs J, Whitney N, Starosta A. Prevalence of orthorexia nervosa is less than 1 %: data from a US sample. Eat Weight Disord. 2017;22(1):185-192. doi:10.1007/s40519-016-0258-8

Health Consequences

Credit to NEDA.

Orthorexia Nervosa is similar to Anorexia Nervosa, in that orthorexia involves certain restrictions such as the amount and variety of foods. This pattern often leads to malnutrition. Therefore the two disorders share the same health consequences.

Cardiovascular System

  • When you don't consume enough calories, the body breaks down its tissue for fuel instead. The first tissue to be used is muscle tissue, including the heart. The more mass the heart loses, the more pulse and blood pressure drop. The heart has less fuel and cells to pump blood, and the risk of heart failure increases.

  • The body will reduce its resting metabolic rate to conserve energy.

  • If the brain and blood vessels can't push enough blood to the brain, it can cause fainting or dizziness, primarily upon standing.

Gastrointestinal System

  • Anorexia can lead to slow digestion, known as gastroparesis. Food restriction interferes with regular stomach emptying and the digestion of nutrients, which can lead to:

  • Stomach pain and bloating

  • Nausea and vomiting

  • Blood sugar fluctuations

  • Blocked intestines from solid masses of undigested food

  • Bacterial infections

  • Feeling full after eating only small amounts of food

  • A patient can develop constipation, from any of the following:

  • Inadequate nutritional intake means the intestines don't have enough material for work properly.

  • Long-term inadequate nutrition can weaken the intestines' muscles and leave them without the strength to propel digested food out of the body

  • Both malnutrition and purging can cause pancreatitis, an inflammation of the pancreas. Symptoms include pain, nausea, and vomiting.


  • The brain consumes almost one-fifth of the body's daily calorie intake. Inadequate nutritional intake causes insufficient energy for the brain.

  • Extreme hunger at bedtime can create difficulties falling or staying asleep.

  • Neurons in all parts of the body require a protective layer of lipids for insulation; these lipids allow neurons to conduct electricity more efficiently. If the body doesn't have enough fat, it can damage this protective layer and cause numbness and tingling.

  • Severe dehydration and malnutrition can lead to electrolyte imbalances. Electrolytes are used by neurons to send electrical and chemical signals in the body. These imbalances can lead to seizures and muscle cramps.


  • Hormones are made from the fat and cholesterol we eat. Without the correct nutrients, levels of the following hormones can fall:

  • Sex hormones estrogen and testosterone

  • Thyroid hormones

  • Lowered sex hormones can

  • cause menstruation to fail to begin, to become irregular, or to stop completely.

  • significantly increase bone loss (known as osteopenia and osteoporosis) and the risk of broken bones and fractures.

  • Reduced resting metabolic rate, a result of the body's attempts to conserve energy.

  • Without enough power to fuel its metabolic fire, core body temperature will drop, and hypothermia may develop.

  • Starvation can cause high cholesterol levels, although this is NOT an indication to restrict dietary fats, lipids, and/or cholesterol.

Other Health Consequences

  • Low caloric and fat consumption can cause dry skin and hair to become brittle and fall out.

  • To conserve warmth during periods of starvation, the body will grow fine, downy hair called lanugo.

  • Severe, prolonged dehydration can lead to kidney failure.

  • Inadequate nutrition can decrease the number of certain types of blood cells.

  • Anemia develops when there are too few red blood cells or too little iron in the diet. Symptoms include fatigue, weakness, and shortness of breath.

  • Malnutrition can also decrease infection-fighting white blood cells.

Treatment Options

There are currently no treatment options for orthorexia, though many patients go through treatment similar to that for anorexia and/or obsessive-compulsive disorder. The standard procedures include exposure and response prevention, behavior modification, cognitive restructuring, and various forms of relaxation training.

The first step to recovery is recognizing the disorder because individuals are less likely to see the adverse effects of orthorexia on their health, well-being, or social function. Education about the nutrition of food can help orthorexia sufferers understand, limit, and eventually eliminate false food beliefs.

Book: Clinical Handbook of Complex and Atypical Eating Disorders

Author: Anderson, L.K.; Murray, S.B.; Kaye, W.H.

Publish Date: September 26, 2017

Price: $69 (Paperback)

Description: "Clinical Handbook of Complex and Atypical Eating Disorders brings together into one comprehensive resource what is known about an array of complicating factors for patients with ED, serving as an accessible introduction to each of the comorbidities and symptom presentations highlighted in the volume. The first section of the book focuses on the treatment of ED in the presence of various comorbidities, and the second section explores the treatment of ED with atypical symptom presentations. The third section focuses on how to adapt ED treatments for diverse populations typically neglected in controlled treatment trials: LGBT, pediatric, male, ethnically diverse, and older adult populations. Each chapter includes a review of clinical presentation, prevalence, treatment approaches, resources, conclusions, and future directions. Cutting edge and practical, Clinical Handbook of Complex and Atypical Eating Disorders will appeal to researchers and health professionals involved in treating ED."

Further Reading: