Eating Disorders 101: Explained by a Registered Dietitian

In the recent years, eating disorder (ED) prevalence in Canada has increased. One million Canadians are affected by an ED at any given time. There are a lot of misconceptions about what EDs are and are not.. Let's dive deep to get a better understanding of eating disorders.

*If you, or someone you know, is struggling with an ED please reach out for help. This article is meant to provide information and is not a substitute for any professional help.

What are EDs?

Eating disorders are serious mental illnesses related to ones relationship to food and eating behaviours that interferes with many aspects of their lives such as thoughts, behaviours, beliefs, feelings, body and relationships. In Canada, ED are diagnosed by a physician or psychologist following guidelines from the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The cause of ED are multifactorial and complexe (view table below for different factors that can contribute to developing an ED)

ED have the highest rate or mortality of all mental illness. According to a 2011 study, 10-15% of individuals struggling with an ED will pass away from complications related to the ED.

It's important to note that eating disorder are not a choice. They are not about vanity or to receive attention. They are not the individuals fault or the parents fault.

Who can be affected by ED?

When people thinking of ED they think of a white underweight teenage girl.. however this is a misrepresentation. ED can affect people of all ages, gender, culture, sexuality, socioeconomic background... A 2002 report (I know a little outdated), showed that 1.5% of women 15-24years old are struggling with an ED. A 2007 study on ED prevalence reported the following:

- Prevalence of anorexia nervosa is 0.9% in women and 0.3% in men      - Prevalence of bulimia nervosa is 1.5% in women and 0.5% in men  (with an average duration of 8.3 years)     - Prevalence of binge eating disorder is 3.5% in women and 2.0% in men. 

Different types of ED?

Anorexia Nervosa

When most people think of ED, they think of anorexia. Anorexia nervosa is characterized by persistant behaviours that interfere with maintaining a healthy weight. These behaviours can varie from restricting food, compensating for food intake through intense exercise, and/or purging through self-induced vomiting or misuse of medications like laxatives, diuretics, enemas, or insulin. It is usually characterized by a very low weight (BMI<19). In adults suffering with anorexia, many will have a severe weight loss where as in children, because they are still growing, some will not experience a weight loss however will not gain any weight despite growth and therefore become underweight.

Individual who suffer from anorexia often have an irrational fear of gaining weight or being fat. The person also often has body dysmorphia, meaning they perceives themselves as being much bigger than they actually are.

Note: Atypical anorexia nervosa has the same characteristic as anorexia nervosa however the person is not necessarily underweight and can even be overweight. This can happen if the person was at a higher weight to start off and drops weight related to restrictive behaviour that can lead to cardiac instability.

Bulimia Nervosa

Bulimia nervosa is associated with periods of restrictions followed by binge episodes and compensatory behaviours such as self-induced vomiting, increased restrictions, intensive workouts, laxatives, diuretics, enemas, etc. The restriction-binge cycle needs to be on-going for at least 1 time per week for 3 months to be diagnosed. Bulimia nervosa can be characterized by weight loss or weight gain (often yo-yoing).

Individuals struggling with bulimia nervosa will typically have extreme concerns with their body (weight, shape and size) and their food intake (same as anorexias nervosa). Individuals often struggle with body dysmorphia as well.

A binge-eating episode is characterized by: 1) The consumption of an unusually large amount of food within a relatively short period of time. (More than you would usually eat in a sitting or in front of other people) 2) Feeling out of control over what and how much you ate (some people have described this as being in a trans/auto-pilot)

Note: Purging (vomiting) can cause severe dehydration, damage to the esophagus, mouth and teeth. Warning signs are tooth pain, discolouration, callus or cutes of hands/knuckles and frequent use of washrooms after meals.

Binge Eating Disorder

Binge Eating Disorder is characterized by frequent episodes of binge eating (read above for definition fo a binge). Binge eating is very different from overeating. Overeating is eating more than the body needs without feeling distress and/or out of control. It is normal for most of us to overeat here and there, like taking an extra portion at meals (pass the point of satiety) or over-indulging during the holidays or celebrations. These occasional overeating periods do not lead to any long term consequences to our health and do not impact our everyday life. Some may experience regret or guilt following over-eating, however, it does not cause distress.

Binge eating, however, is characterized by eating an excessive amounts of calories (pass the point of satiety) in a short period of time and is accompanied by feeling guilt, shame and distress. Binge eating disorder is diagnosed when an individual has these binge eating episodes 1x/week for at least 3 months. Many people will feel embarrassment, self-disgust, guilt, depression.

The binge-eating episodes are not followed by compensating behaviours (such as excessive exercise, self-induced vomiting, or the misuse of laxatives or diuretics) as in bulimia nervosa.

Note: Binge eating disorder usually leads to weight gain. However not all people who suffer from binge eating disorder live in larger bodies.

Avoidant and Restrictive Food Intake Disorder

This disorder usually happens during infancy and childhood. An infant/child may start avoiding foods related to textures or colours, or a traumatic experience involving food (i.e food poisoning or choking on food) which result in a fear of eating. Most times, this disorder has nothing to do with controlling body weight or shape. Some parents may describe this as extreme picky eater however it goes beyond that. This ED can lead to malnutrition and failure to thrive.

Other Specified Feeding or Eating Disorder

These disorders are all related to anorexia nervosa, bulimia nervosa and binge eating disorder however differs in some characteristics. Here are some example:

Atypical Anorexia Nervosa: same characteristic as anorexia nervosa however the person is not necessarily underweight and can even be overweight.

- Bulimia nervosa type: same characteristics as bulimia nervosa, however the symptoms (binge/purge cycle) occurs less frequently.

- Binge-eating disorder type: same characteristics as for binge-eating disorder however the binge-eating episodes occur less frequently.

- Night eating syndrome: The excessive consumption of food (not necessarily a binge) usually in the middle of the night that creates distress and interferes with everyday life.

- Purging disorder: Purging behaviours without the presence of binge-eating episodes.

Other Eating Disorders

PICA : Persistant consumption of non-food items for at least a month. (Example of non-food substances: paper, wood, pen, chalk, clay, soil, wool, soap, cloth, hair, ...)

Rumination disorder: Persistant regurgitation of chewed and/or partially digested food over a period of at least a month. This can also be a symptom of anorexia or bulimia.

Orthorexia: Obsessive behaviours around eating behaviours. The individuals is fixated on 'healthy' eating and may not recognize their behaviour as being obsessive. This is not formerly recognize as an ED therefore there are no diagnostic criteria. (I will be doing a full blog post on this disorder as this is becoming more commonly known.)


There are many factors involved in the development of an ED. People of all gender, age, sexual orientation, colour, size, culture, socioeconomic background can be affected. There are different kind of ED ( anorexia nervosa, bulimia nervosa, binge eating disorder, other specified feeding or eating disorder and other eating disorders) with their own set of characteristic and symptoms. ED are not simple, about vanity or a conscious choice. They are serious mental illness and individual struggling require professional help.

I hope this article provided value for you and hopefully a better understanding of what ED are and are not!

If you are struggling with an ED or anybody you know- Please reach out.

Marie-Pier Pitre-D'Iorio, RD, B.Sc.Psychology


Arcelus, J., Mitchell, A. J., Wales, J., & Nielsen, S. (2011). Mortality rates in patients with anorexia nervosa and other eating disorders: A meta-analysis of 36 studies. Archives of General Psychiatry, 68, 724-731.

Government of Canada. (2006). The Human Face of Mental Health and Mental Illness in Canada 2006. 

Hoek, H. W. (2007). Incidence, prevalence and mortality of anorexia and other eating disorders. Current Opinion in Psychiatry, 19(4), 389-394.

Hudson, J. I., Hiripi, E., Pope, H. G. & Kessler, R. C. (2007). The Prevalence and Correlates of  Eating Disorders in the National Comorbidity Survey Replication. Biological Psychiatry, 61(3), 348-358. 

Sullivan, P. (2002). Course and outcome of anorexia nervosa and bulimia nervosa. In Fairburn, C. G. & Brownell, K. D. (Eds.). Eating Disorders and Obesity (pp. 226-232). New York, New York: Guilford.

134 views0 comments
  • White LinkedIn Icon
  • White Facebook Icon
  • White YouTube Icon
  • White Instagram Icon

The Balanced Dietitian