Nearly everyone has seen the images: an impossibly thin young girl, obsessively toying with food but never eating it, the details of her skeleton clearly visible through her dry flesh; or the young woman with bulimia, compulsively stuffing herself with thousands of junk-food calories, then vomiting back everything she has eaten and doing it all over again, sometimes many times a day.

Rooted in deep psychological, cultural, and physical dysfunctions, an eating disorder is one of the most stubborn problems a person can face. In recent years, these mysterious illnesses have received a torrent of media attention—as the subject of television movies and talk shows, and as grist for the tabloids. One celebrity after another (usually female) has revealed her personal battle with these disorders. Some, like the late Princess Diana and actress Jane Fonda were bulimics. Others, such as TV actress Tracy Gold, were anorexic. Perhaps the most dramatic and horrifying stories are those of anorexic women who have starved themselves to death: rock and roll star Karen Carpenter, only 32 when she died in 1983; or more recently, gymnast Christy Henrich, 22, who weighed just 43 pounds at the time of her death, which was attributed to multiple organ failure.

Anorexia nervosa and bulimia nervosa have long been classified as psychiatric illnesses. A third eating disorder, binge-eating syndrome, was recently added to the basic psychiatric guidelines. Together, they can be viewed as variations on a theme of extreme eating behavior—from not eating at all (anorexia), to bingeing-and-purging (bulimia), to eating nearly all the time (binge-eating syndrome). It takes a combination of medical, psychological, and nutritional therapy to overcome any of these disorders. Treatment usually involves the patient's family as well, especially in the case of anorexics, who are frequently adolescent girls.

Eating disorders can be found around the world, but they are most common in industrialized western nations where food is abundant. In the United States, there are many strong cultural influences at work that most experts agree contribute to the development of eating disorders. Women in particular are the target of a constant barrage of subtle and not-so-subtle "thinner-is-better" messages, and by most counts, they account for about 90 percent of those with eating disorders.

(The male version of the problem has been dubbed the "Adonis complex." Known medically as muscle dysmorphia, its hallmark is a quest for extreme muscularity that can lead not only to eating disorders but also to abuse of drugs such as anabolic steroids. Its victims are less likely to seek help than their female counterparts.)

Estimates of the number of people with eating disorders vary, in part because the disorders are often characterized by secretive behavior and can remain undetected until serious health problems develop. Some studies estimate that one to four percent of adolescent and young adult women in this country have an eating disorder, with concentrations in some subgroups such as college students and athletes. Among college-aged women, as many as 25 percent develop an eating disorder (in four out of five cases, bulimia). And one national study of adolescents found that nearly 9 percent of the girls and more than 4 percent of the boys were involved in binge/purge activities at least once a day. The National Association of Anorexia Nervosa and Associated Disorders (ANAD), an educational and self-help organization, estimates that seven million women and one million men in this country have eating disorders.

Eating disorders usually begin early in life. The period between 14 and 18 years old is the riskiest; and by age 20, fully 86 percent of people with eating disorders have already experienced symptoms, according to ANAD. These symptoms, which vary by disorder, can continue for years, or even decades. And it is important to remember that the statistics show only the tip of the iceberg. Individuals with problems serious enough to be diagnosed as eating disorders represent only a fraction of those people who have fasted or binged or purged at some point in their lives.

Some 44 percent of adult women and adolescent girls, 29 percent of adult men, and 15 percent of adolescent boys say they are trying to lose weight. One study of college-aged women found that 91 percent wanted to lose weight—a percentage the investigator called "astonishing." A survey of high school girls around the country determined that 39 percent thought they were overweight, 58 percent had dieted at some time, and 20 percent had binged and purged. Lately the statistics have been boosted by the sobering fact that childhood obesity has become a national epidemic—today nearly 25 percent of all children are overweight, with the rates among minority children even higher.

Serious problems may begin as diets that go out of control, or as an obsession with food that grows out of a seemingly healthy interest in good nutrition. Studies have found that from 3 to 5 percent of adolescent girls have subclinical eating disorders—not serious enough to merit a full-blown diagnosis, but serious enough to cause health and life problems.

Children with chronic diseases such as asthma and diabetes are particularly at risk for developing an eating disorder. Diabetes patients, for instance, are counseled to count and keep track of everything they eat, a habit that can quickly lead to compulsive behavior. Eating disorders strike almost twice as often among teenage girls with type 1 diabetes as in girls without the disease. To shed pounds, many of these girls simply skip taking their insulin or cut back on the dose—a strategy that leads to weight loss, but also invites the serious and even fatal complications of diabetes.

Also, paralleling the upsurge of obesity in young people is a corresponding epidemic of type 2 diabetes in children. Previously, type 2 was diagnosed almost exclusively in adults (typically, those with weight problems). Now it's showing up in more and more children, particularly among minorities. Children with type 2 don't need to take insulin, since their body continues to produce it, but they still need to monitor their food, putting them at risk of compulsive eating disorders.

In the past two decades there has been a growing interest in eating disorders in the medical and psychiatric communities. Many programs now exist to treat them, and family physicians and other health professionals are becoming increasingly sophisticated in recognizing symptoms. Experts now favor a multidisciplinary approach to treatment, with help from psychiatrists, pediatricians or family doctors, psychologists, dietitians, and social workers. Prevention is also receiving increasing attention, through both school and community-based programs. Nutritional education at an early age, especially for young athletes and others who are considered high-risk, can sometimes prevent eating disorders from developing or from going out of control.

Anorexia, bulimia, and binge-eating have much in common. All are centered on food, and all involve extreme control or lack of control in eating behavior. They are often accompanied by low self-esteem, depression, thoughts of suicide, and high levels of stress. Increasingly, doctors are also noting a link with substance abuse. All three disorders can overlap or alternate in the same person, with anorexics sometimes developing binge/purge behavior and bulimics going through periods of fasting. Despite these similarities each is a distinct disorder with its own symptoms, patterns, and treatment.