Anorexia Nervosa
Anorexia nervosa (AN) is a disorder in which individuals exhibit significant weight loss and extreme restrictions in their food intake.

While it has been estimated that up to 90%¹ of those suffering from this disorder are women and girls, the prevalence rate of eating disorders among men is on the rise. Although not limited to, this disorder is primarily seen among individuals of middle and high socioeconomic statuses².

It has been estimated that 0.5 to 3.7% % of the population suffers from anorexia nervosa³. However, this prevalence rate does not consider the amount of individuals who exhibit extreme restrictions in their food intake, but who do not qualify for a formal diagnosis. Additionally, with the mortality rate of females with AN estimated to be around 10%, AN is considered to have the highest mortality rate among any psychological disorder⁴.

The Diagnostic and Statistical Manual, 4th Edition (DSM-IV) lists the following criteria for diagnosis of anorexia nervosa:

• Refusal to maintain what is considered a normal body weight for that person’s age and height
• Intense fear of gaining weight
• Distorted view or denial of their actual body weight and/or shape
• Loss of menstrual cycle

Anorexia nervosa is specified into two types:

1. Restricted Type:
• This type of anorexia is categorized as a severe restriction of food intake with the absence of binge-eating or purging.

2. Binge-Eating/Purging Type:
• This type of anorexia is categorized as engaging in binge eating or purging behavior while exhibiting behaviors classified as anorexia. Purging is characterized as a way to eliminate food from your body either through self-induced vomiting, excessive exercise, or through laxatives, diuretics, or enemas.

In addition to the diagnostic criteria, the following are considered warning signs, or possible precursors, of anorexia nervosa:

• Restricting certain types of food and the amount of food intake
• Preoccupation with weight, body shape, and calorie and fat content of food
• Dramatic weight loss
• Excessive exercise
• Distress over body weight and shape
• Withdrawal from previously enjoyed activities, and from family and friends

Bulimia Nervosa
Bulimia nervosa (BN) is a disorder in which individuals eat excessive amounts of food in a short period of time and afterwards eliminate this food from their body through some type of purging behavior. It is estimated that 1.1 to 4.2% of the female population suffers from BN⁵. However, less is known about the population of males suffering from BN. As is the same with estimates of AN, prevalence rate does not consider the amount of individuals who are experiencing similar behaviors as seen in BN, but who do not qualify for a formal diagnosis.

The Diagnostic and Statistical Manual, 4th Edition (DSM-IV) lists the following criteria for diagnosis of bulimia nervosa:

• Recurring episodes of binge eating, characterized as an uncontrollable consumption of food in a short period of time
• Episodes of purging behavior following binging episode in which the individual tries to prevent weight gain through self-induced vomiting, laxatives, diuretics, enemas, fasting, or excessive exercise
• Self-evaluation is influenced by weight and body shape.

Bulimia nervosa is specified into two types:

• Purging Type: In this type of bulimia, purging behavior is in the form of self-induced vomiting or through the use of laxatives, diuretics, or enemas.
• Nonpurging Type: In this type of bulimia, fasting or excessive exercise is the compensatory behavior that is used to prevent weight gain. There is no self-induced vomiting.

Binge Eating Disorder
Recent attention has been paid to another category of eating disorder, binge eating disorder. Similar to those suffering from BN, individuals with binge eating disorder consume large quantities of food in a short amount of time. However, these individuals do not use compensatory behavior in an attempt to eliminate their food. Prevalence of binge eating disorder is on the rise; however, more research is needed to fully understand the scope and nature of this disorder.

¹ Gidwani, G. P., Rome, E. S. (1997). Eating disorders. Clinical Obstetrics and Gynecology, 40, 601-615.
² Keel, P. K., & Klump, K. L. (2003). Are eating disorders culture- bound syndromes? Implications for conceptualizing their etiology. Psychological Bulletin, 129, 747-769.
³ American Psychiatric Association Work Group on Eating Disorders. Practice guideline for the treatment of patients with eating disorders. American Journal of Psychiatry, 2000, 157, 1-39.
⁴ Birmingham, C. L., Su, J., Hlynsky, J. A., Goldner, E. M. (2005). The mortality rate from anorexia nervosa. International Journal of Eating Disorders, 38, 143–146.
⁵ American Psychiatric Association Work Group on Eating Disorders. Practice guideline for the treatment of patients with eating disorders. American Journal of Psychiatry, 2000, 157, 1-39.