An eating disorder is marked by extremes. It is present when a person experiences severe disturbances in eating behavior, such as extreme reduction of food intake or extreme overeating, or feelings of extreme distress or concern about body weight or shape.

A person with an eating disorder may have started out just eating smaller or larger amounts of food than usual, but at some point, the urge to eat less or more spirals out of control. Eating disorders are very complex, and despite scientific research to understand them, the biological, behavioral and social underpinnings of these illnesses remain elusive.

The two main types of eating disorders are anorexia nervosa and bulimia nervosa. A third category is “eating disorders not otherwise specified (EDNOS),” which includes several variations of eating disorders. Most of these disorders are similar to anorexia or bulimia but with slightly different characteristics. Binge-eating disorder, which has received increasing research and media attention in recent years, is one type of EDNOS.

Eating disorders frequently appear during adolescence or young adulthood, but some reports indicate that they can develop during childhood or later in adulthood. Women and girls are much more likely than males to develop an eating disorder. Men and boys account for an estimated 5 to 15 percent of patients with anorexia or bulimia and an estimated 35 percent of those with binge-eating disorder. Eating disorders are real, treatable medical illnesses with complex underlying psychological and biological causes. They frequently co-exist with other psychiatric disorders such as depression, substance abuse, or anxiety disorders. People with eating disorders also can suffer from numerous other physical health complications, such as heart conditions or kidney failure, which can lead to death.

What is bulimia nervosa?
Bulimia means eating large amounts of food and then trying to undo the effects by starving themselves, or by vomiting or, less usually, by using laxatives (both known as purging). In extreme cases, someone can be making themselves sick as often as 30 to 40 times a day.
Bulimia is more common than anorexia, but because people keep their weight roughly the same, it’s not so visible.

People are often at great pain to keep the bulimia outwardly hidden. Inwardly, they will be thinking constantly about eating, and having irresistible cravings for particular foods. They dread being fat and believe they should be much thinner than a normal weight.

Contrary to what people believe, taking laxatives doesn’t actually help with weight loss, but removes essential minerals, such as potassium and sodium, which keep the muscles working. Being sick gets rid of less than half the calories consumed, according to one study, and diuretic drugs, which rid the body of fluid, have no effect on the calories absorbed. A flat stomach may be a temporary benefit, but it soon returns to normal when fluid levels rise again.
Media attention has glamorised, and so trivialised, bulimia nervosa. But the effects are not trivial. They include having poor skin, because of being dehydrated, bad teeth caused by stomach acids eroding the tooth enamel, bad breath, a sore throat and mouth ulcers. Periods may also become irregular or stop altogether. Frequent vomiting can cause epileptic fits, muscular weakness and heart problems, while taking a lot of laxatives can also cause permanent damage.

What is anorexia?

Anorexia nervosa, commonly referred to simply as anorexia, is one type of eating disorder. More importantly, it is also a psychological disorder. Anorexia is a condition that goes beyond out-of-control dieting. A person with anorexia initially begins dieting to lose weight. Over time, the weight loss becomes a sign of mastery and control. The drive to become thinner is actually secondary to concerns about control and/or fears relating to one’s body.

The individual continues the endless cycle of restrictive eating often to a point close to starvation in order to feel a sense of control over the body. This cycle becomes an obsession and is similar to any type of drug or substance addiction.

What causes anorexia?

At this time, no definite cause of anorexia nervosa has been determined. However, research within the medical and psychological fields continues to explore possible causes.

Some experts feel that demands from society and families could possibly be underlying causes for anorexia. For many individuals with anorexia, the destructive cycle begins with the pressure to be thin and attractive. A poor self-image compounds the problem.

Other researchers feel that this disorder can stem from a particular dysfunction often seen in families of anorexia patients. In one particular type of dysfunction, family members become so interdependent that each cannot achieve their identity as an individual. Thus, family members are unable to function as healthy individuals and are dependent on other family members for their identity. In children, part of this dysfunction includes a fear of growing up (especially girls). Restrictive dieting may prevent their bodies from developing in a normal manner, and in their thinking, restricts the maturational process and maintains the parent-child relationship that the family has come to rely on. Other family situations that have been suggested, but not proved, as possibly being related to the development of anorexia nervosa include high parental expectations, poor communications skills, and problems with conflict management.

Some studies also suggest that a genetic (inherited) component may play a role in determining a person’s susceptibility to anorexia. Researchers are currently attempting to identify the particular gene or genes that might affect a person’s tendency to develop this disorder.

Although no organic cause for anorexia has been identified, some evidence points to a dysfunction in the part of the brain (hypothalamus) which regulates certain metabolic processes. Other studies have suggested that imbalances in neurotransmitter levels in the brain may occur in people suffering from anorexia.