About Eating Disorders
Types of Eating Disorders
How common are they?
What causes them?
How long do they last?
What treatments are effective?
A review of the evidence
What's new?
Resources

Types of Eating Disorders

Anorexia Nervosa
Anorexia Nervosa (AN) is a condition characterized by a refusal to maintain at least a minimally normal body weight, excessive fear of gaining weight, and a distorted perception of body size and shape.

There are two subtypes.  The restricting type of AN is one in which weight loss is achieved by restricting food intake, fasting, or by excessive exercise.  A second type is binge eating and purging, in which individuals overeat (binge) and then use laxatives or diuretics (“water pills”), or self-induced vomiting (purging), to control their weight.  In this group, some who do not actually binge will purge whenever they eat. 

Control over calorie intake and use are important to the person with AN.  Loss of weight does not seem to satisfy the person with AN, and can, in fact, spur further dieting because of increasing concern with weight and with food. 

People with AN frequently have symptoms of major depression such as low mood, irritability, social withdrawal, sleep problems and loss of interest in sex.  AN is not a benign condition – many individuals suffer lifelong effects including infertility, serious tooth damage (from the vomiting), heart problems, bone loss, kidney damage, anemia, and even premature death.

Bulimia Nervosa
Bulimia Nervosa (BN) is an eating disorder characterized by episodes of severe overeating within a specific period of time (for instance, over a few hours) followed by purging through self-induced vomiting, use of laxatives or enemas, diuretics or other medications, fasting, or excessive exercise. 

Unlike AN, people feel a lack of control over their behavior, being unable to either stop eating or to control how much or what they eat. Some people with BN have psychological problems like depression or personality problems that precede the eating disorder.

Binge-eating Disorder
Binge-eating Disorder is a fairly new type of eating disorder that has not yet been approved as a formal psychiatric diagnosis.  It is characterized by the same binge-eating behaviour as Anorexia Bulimia (BN) but without the purging that accompanies those with bulimia. 

People with Binge-eating Disorder engage in bouts of out-of-control eating, taking in excessive amounts of food within short periods of time even when not physically hungry.  They eat faster than normal and to the point where they feel uncomfortably full.  They also experience extreme distress at their binge-eating behaviour, which leads to further bingeing.  Because they do not purge, these individuals are typically overweight, rather than thin like those with Anorexia Nervosa (AN) or bulimia.

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