Who is affected?

Eating disorders usually start during adolescence or young adulthood and are more common among youth in industrialized societies. However, eating disorders, and especially anorexia, are observed in cultural contexts beyond those in which a culture of thinness prevails.

AN and BN affect girls and women more than boys and men. Men represent about 10 percent of individuals with eating disorders. BED has a more even distribution across sexes, affecting about 2 males for every 3 females. BED occurs in somewhat more mature individuals, affecting on average individsuals in their 40s.

As in other western countries, approximately 3 percent of Quebec women between the age of 13 and 30 (i.e. 30,000 people) are affected by an eating disorder. This number can triple if we include the partial forms of these disorders that can have a significant impact on affected people.

Experts agree that more and more people are struggling with eating disorders. Although statistics show a higher incidence of EDs among school-age Western women, the truth is that everyone is at risk.

  • Although more present in industrialized societies, eating disorders occur even in developing countries
  • Eating disorders affect all socio-economic classes equally
  • There are few ethnic or racial factors that influence the prevelance of eating disorders in North Amercia

Causes of eating disorders

The research of Steiger and Bruce, of Treasure and of Striegler-Moore show that eating disorders are likely caused by a combination of biological, psychological, environemental and social risk factors.

Genetic liabilities affect mood, behavioral controls, reward mechanisms, energy metabolism and appetite. Environmental stresses like perinatal insults or childhood trauma also play a role. So do state-related effects (owing to the nutritional and mental status) and ultimately, social inducements toward intensive dieting.

Biological factors

They include heredity, weight problems, and family history of depression, anxiety, or eating disorders.

Many studies have demonstrated the role of genetics in eating disorders. EDs are clearly transmitted within families, meaning that heredity is indeed a factor. While study data have not proven that eating disorders are automatically transmitted from mother to daughter, for example, they do indicate a possible transmission of temperamental traits or a vulnerability to other stressors that seem to increase the risk of developing these disorders.

Defects involving the neurotransmitters that regulate appetite and mood are also thought to have an influence on eating disorder development. Researchers at the Douglas are now carrying out cutting-edge studies on this subject. Their research also focus on the genetic factors of eating disorders and the brain activity of the persons suffering from the disease.

Social factors

Society has always conveyed an ideal model of beauty, and over time this ideal has become thinner and thinner to the point of emaciation. The media contribute to this ideal by reinforcing many stereotypes and standards that put pressure on women and drive them to follow draconian diets that are harmful to health.

This cult of thinness also stems from multi-billion dollar marketing strategies. Women must appear submissive and are only valued when seen as objects or as delicate and dependent. However, these ideals of thinness and femininity are simply marketing tools that help fuel a prolific industry.

Social pressure is associated more with the different forms of bulimia rather than with anorexia. Indeed, bulimia seems to have increased noticeably in recent years and is localized more specifically to industrialized societies. Anorexia, on the other hand, has been present around the world for a long time and is therefore thought to be less connected to social factors.


The media is filled with advertising about so-called miracle or foolproof diets, and dieting often acts as an eating disorder trigger in many people with a genetic predisposition. Without doubt, the first step for these individuals is to stop dieting.

Diets can also have harmful physical effects. For example, a moderate three-week diet can alter cerebral function and reduce the substances that control mood, thought and satiety.

Family influence

It is the position of the Academy for Eating Disorders (2010) that "whereas family factors can play a role in the genesis and maintenance of eating disorders, current knowledge refutes the idea that they
are either the exclusive or even the primary mechanisms that underlie risk."

Psychological factors

Eating Disorders often co-aggregate with affective, anxiety and impulse-control disorders. They also coexist with problems such as behavioural control, negative emotionality and maladaptive perfectionism/self-criticism.

There are, however, striking individual differences as to comorbid characteristics:

  • About 30% of those affected are frankly “dysregulated” : they are emotionally unstable and impulsive
  • A third is “over-regulated” : they are emotionally over-controlled and inhibited
  • Another third is quite free of psychopathology

In other words, eating disorders occur in a very wide range of people. Variations inspire the belief that, in different people, eating disorders correspond to different exposures to developmental and constitutional risks and, more importantly, to different treatment needs

Consequences of eating disorders

Psychological consequences

  • Anxiety
  • Impulsivity
  • Withdrawal
  • Sleep disturbances
  • Obsessive thoughts
  • Emotional changes
  • Difficulty concentrating
  • Food preoccupations
  • Depressed mood, irritability
  • Impaired intellectual abilities.

Physical consequences



General signs
  • Weight loss
  • Hyperactivity
  • Hair loss
Skin signs
  • Lanugo (downy hairs)
  • Acrocyanosis (bluish coloration of the extremities)
  • Carotenemic complexion (orange-coloured complexion)
Other signs
  • Hormonal changes and osteoporosis
  • Electrolyte imbalance
  • Slowed heartbeat
  • Arrhythmia
  • Anemia
  • Reproductive system
  • Absent menstruation
  • Obstetric complications
Oral signs
  • Swollen salivary glands
  • Dental cavities
  • Dental erosion
  • Bleeding gums
Cardiovascular signs
  • Hypotension
  • Arrhythmia
Digestive signs
  • Esophageal inflammation
  • Blood-filled vomit
Other signs
  • Higher rate of obstetric complications


[Eating Disorders: what are they?] [Eating Disorders: causes and symptoms] [Eating Disorders: treatments] [Eating Disorders: advice for the family]