Eating Disorders
(Bulimia · Anorexia)
In this condition factsheet:
The Facts on Eating Disorders
Eating disorders have increased in frequency as a consequence of society's emphasis and preoccupation with thinness. Eating disorders are multifactorial conditions linked to genetic, traumatic, and nutritional causes. In North America, anorexia nervosa and bulimia nervosa are the two most common eating disorders. They predominantly affect women.
Anorexia nervosa is a psychiatric condition in which people intentionally starve themselves because of a false belief that they are fat, or for fear of becoming obese. In reality, they are almost always underweight or of normal weight when the condition starts. It is estimated that more than 90% of all those diagnosed with anorexia nervosa are women, often from middle and upper socioeconomic backgrounds. This disorder usually starts in the years between adolescence and young adulthood, with the average age at onset of 14 years. Anorexia nervosa afflicts about 1 in 100,000 people in the population at large, but the rate is believed to be higher among Caucasian adolescent girls, about 1 in 200.
Bulimia nervosa is an eating disorder characterized by uncontrolled or compulsive binge eating, usually followed by inappropriate ways of trying to get rid of the food. Most often, this involves purging by self-induced vomiting or abuse of laxatives, enemas, or diuretics. It's also sometimes called the "binge-purge syndrome." Some people with bulimia don't purge, but will overeat (consuming as many as 20,000 calories at one time) and then compensate for binge-eating sessions with other behaviours such as fasting or over-exercising. A person with bulimia may secretly binge anywhere from twice a day to several times a day. In most cases, binge eating is followed by purging. A person with bulimia may use as many as 20 or more laxatives at a time.
Bulimia commonly appears in the latter part of adolescence, between the ages of 18 and 20, but it can develop at an earlier or later age. Like anorexia, bulimia predominantly affects young, Caucasian, middle- and upper-class women. The American Psychiatric Association estimates that between 0.3% and 3.7% of women experience anorexia and between 1.0% and 4.2% experience bulimia at some point in their lifetime. One difference between people with bulimia and anorexia nervosa is that people with bulimia are aware of their problems with food yet they don't feel in control of their condition.
Causes of Eating Disorders
Eating disorders are generally viewed as being psychological in origin. However, like depression, schizophrenia, and bipolar affective disorder, they are currently believed to have many causes - including genetic and functional changes in the brain. People suffering from anorexia and bulimia have preoccupations with body image, weight, and eating. They also have a distorted personal body image and a fear of fatness and weight gain.
Although cultural factors have an influence on the development of eating disorders, they appear to stem from multiple factors. There's been a lot of debate about the role of faulty parenting and dysfunctional family environments in relation to eating disorders. Genetic and hormonal factors are believed to play significant roles; people with eating disorders are believed to have a genetic predisposition to the illness. Individuals who have a family history of depression, alcohol abuse, obesity, or eating disorders are at higher risk for anorexia nervosa and bulimia nervosa. There also appears to be a neurologic relationship between eating behaviour patterns (such as dieting and starvation) and the nervous and hormonal systems, since hunger, food cravings, and feelings of fullness are controlled by certain areas of the brain and involve a number of digestive hormones.
Symptoms and Complications of Eating Disorders
People with anorexia nervosa may appear severely emaciated due to malnutrition, sometimes so severe their ribs can be seen through the skin. Other common symptoms of anorexia include:
- constipation
- dehydration
- depression
- dizziness
- dry, scaly skin
- faintness or weakness
- inability to concentrate
- intolerance to cold
- irritability
- loss of body fat
- low blood pressure
- missed, or absence of, menstrual periods
- psychological fears of obesity and weight gain
- slow heartbeat
While most people feel hungry and uncomfortable when their calorie intake is low or restricted, people with anorexia suppress this discomfort and usually lose the ability to appreciate normal hunger cues. As they begin to starve, they may experience a feeling of euphoria, similar to how a runner or jogger gets the well-known "runner's high."
If the onset of anorexia occurs before puberty, a girl's sexual development will stop and menstruation won't begin. Severe anorexia leads to chronic malnutrition, which has damaging effects on the body, especially the thyroid, heart, and digestive and reproductive systems. Anorexia can be fatal. Half of those who die with anorexia die of suicide, and the other half die of medical complications.
Some people with bulimia may experience episodic weight loss, while others maintain a normal weight. In some cases, menstrual cycles may be affected and stopped, but menstruation is usually preserved. Possible symptoms of bulimia include:
- dehydration (due to excess use of laxatives or frequent self-induced vomiting)
- tooth decay and erosion (due to the acids that are brought up from severe and constant vomiting)
- low blood pressure
- constipation
- swollen cheek glands (like mumps)
- abnormal hormone levels
- stomach problems
- irregular heartbeat
A variety of complications can result from the constant vomiting. For example, inflammation of the esophagus (called esophagitis) and severe dental problems can occur. At its worst, constant purging can lead to heart damage. People with bulimia may have a history of anorexia or obesity. They may also have psychiatric problems such as depression, panic disorder, social phobias, and anxiety disorders, as well as addictive behaviours like alcohol or drug abuse.
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