Each year millions of people in the United States develop serious and sometimes life-threatening eating disorders. The vast majority -- more than 90 percent -- of those afflicted with eating disorders are adolescent and young adult women. One reason that women in this age group are particularly vulnerable to eating disorders is their tendency to go on strict diets to achieve an "ideal" figure. Researchers have found that such stringent dieting can play a key role in triggering eating disorders.1
Approximately 1 percent of adolescent girls develop anorexia nervosa, a dangerous condition in which they can literally starve themselves to death. Another 2 to 3 percent of young women develop bulimia nervosa, a destructive pattern of excessive overeating followed by vomiting or other "purging" behaviors to control their weight. These eating disorders also occur in men and older women, but much less frequently.
The consequences of eating disorders can be severe, with 1 in 10 cases leading to death from starvation, cardiac arrest, or suicide. Fortunately, increasing awareness of the dangers of eating disorders--sparked by medical studies and extensive media coverage of the illness--has led many people to seek help. Nevertheless, some people with eating disorders refuse to admit that they have a problem and do not get treatment. Family members and friends can help them recognize the problem and encourage the person to seek treatment.
People who intentionally starve themselves suffer from an eating disorder called anorexia nervosa. The disorder, which usually begins in young people around the time of puberty, involves extreme weight loss--at least 15 percent below the individual's normal body weight. Many people with the disorder look emaciated but are convinced they are overweight. Sometimes they must be hospitalized to prevent starvation.
One of the most frightening aspects of the disorder is that people with anorexia continue to think they are overweight even when they are bone-thin. For reasons not yet understood, they become terrified of gaining any weight.
Food and weight become obsessions. For some, the compulsiveness shows up in strange eating rituals or the refusal to eat in front of others. It is not uncommon for people with anorexia to collect recipes and prepare gourmet feasts for family and friends, but not partake in the meals themselves. They may adhere to strict exercise routines to keep off weight. Loss of monthly menstrual periods is typical in women with the disorder. Men with anorexia often become impotent.
People with bulimia nervosa consume large amounts of food and then rid their bodies of the excess calories by vomiting, abusing laxatives or diuretics, taking enemas, or exercising obsessively. Some use a combination of all these forms of purging. Because many individuals with bulimia "binge and purge" in secret and maintain normal or above normal body weight, they can often successfully hide their problem from others for years.
Family, friends, and physicians may have difficulty detecting bulimia in someone they know. Many individuals with the disorder remain at normal body weight or above because of their frequent binges and purges, which can range from once or twice a week to several times a day. Dieting heavily between episodes of bingeing and purging is also common. Eventually, half of those with anorexia will develop bulimia.
As with anorexia, bulimia typically begins during adolescence. The condition occurs most often in women but is also found in men. Many individuals with bulimia, ashamed of their strange habits, do not seek help until they reach their thirties or forties. By this time, their eating behavior is deeply ingrained and more difficult to change.
Binge Eating Disorder
An illness that resembles bulimia nervosa is binge eating disorder. Like bulimia, the disorder is characterized by episodes of uncontrolled eating or bingeing. However, binge eating disorder differs from bulimia because its sufferers do not purge their bodies of excess food.
Individuals with binge eating disorder feel that they lose control of themselves when eating. They eat large quantities of food and do not stop until they are uncomfortably full. Usually, they have more difficulty losing weight and keeping it off than do people with other serious weight problems. Most people with the disorder are obese and have a history of weight fluctuations. Binge eating disorder is found in about 2 percent of the general population--more often in women than men. Recent research shows that binge eating disorder occurs in about 30 percent of people participating in medically supervised weight control programs.
Eating disorders have among the highest mortality rates of all mental disorders, killing up to 10 percent of their victims. Individuals with eating disorders who use drugs to stimulate vomiting, bowel movement, or urination are in the most danger, as this practice increases the risk of heart failure.
In patients with anorexia, starvation can damage vital organs such as the heart and brain. To protect itself, the body shifts into "slow gear": monthly menstrual periods stop, breathing, pulse, and blood pressure rates drop, and thyroid function slows. Nails and hair become brittle; the skin dries, yellows, and becomes covered with soft hair called lanugo. Excessive thirst and frequent urination may occur. Dehydration contributes to constipation, and reduced body fat leads to lowered body temperature and the inability to withstand cold.
Mild anemia, swollen joints, reduced muscle mass, and light-headedness also commonly occur in anorexia. If the disorder becomes severe, patients may lose calcium from their bones, making them brittle and prone to breakage. They may also experience irregular heart rhythms and heart failure. In some patients, the brain shrinks, causing personality changes. Fortunately, this condition can be reversed when normal weight is reestablished.
In research supported by the National Institute of Mental Health, scientists have found that many patients with anorexia also suffer from other psychiatric illnesses. While the majority have co-occurring clinical depression, others suffer from anxiety, personality, or substance abuse disorders, and many are at risk for suicide. Obsessive-compulsive disorder (OCD), an illness characterized by repetitive thoughts and behaviors, can also accompany anorexia. Individuals with anorexia are typically compliant in personality but may have sudden outbursts of hostility and anger or become socially withdrawn.
Bulimia nervosa patients--even those of normal weight--can severely damage their bodies by frequent binge eating and purging. In rare instances, binge eating causes the stomach to rupture; purging may result in heart failure due to loss of vital minerals, such as potassium. Vomiting causes other less deadly, but serious problems--the acid in vomit wears down the outer layer of the teeth and can cause scarring on the backs of the hands when fingers are pushed down the throat to induce vomiting. Further, the esophagus becomes inflamed and the glands near the cheeks become swollen. As in anorexia, bulimia may lead to irregular menstrual periods. Interest in sex may also diminish.
Some individuals with bulimia struggle with addictions, including abuse of drugs and alcohol, and compulsive stealing. Like individuals with anorexia, many people with bulimia suffer from clinical depression, anxiety, OCD, and other psychiatric illnesses. These problems, combined with their impulsive tendencies place, them at increased risk for suicidal behavior.
People with binge eating disorder are usually overweight, so they are prone to the serious medical problems associated with obesity, such as high cholesterol, high blood pressure, and diabetes. Obese individuals also have a higher risk for gallbladder disease, heart disease, and some types of cancer. Research at NIMH and elsewhere has shown that individuals with binge eating disorder have high rates of co-occurring psychiatric illnesses--especially depression.
Causes of Eating Disorders
In trying to understand the causes of eating disorders, scientists have studied the personalities, genetics, environments, and biochemistry of people with these illnesses. As is often the case, the more that is learned, the more complex the roots of eating disorders appear.
Most people with eating disorders share certain personality traits: low self-esteem, feelings of helplessness, and a fear of becoming fat. In anorexia, bulimia, and binge eating disorder, eating behaviors seem to develop as a way of handling stress and anxieties.
People with anorexia tend to be "too good to be true." They rarely disobey, keep their feelings to themselves, and tend to be perfectionists, good students, and excellent athletes. Individuals with bulimia tend to be impulsive and more likely to engage in risky behavior such as abuse of alcohol and drugs.
Eating disorders appear to run in families--with female relatives most often affected. This finding suggests that genetic factors may predispose some people to eating disorders, however, other influences--both behavioral and environmental--may also play a role.
In an attempt to understand eating disorders, scientists have studied the biochemical functions of people with the illnesses. They have focused recently on the neuroendocrine system--a combination of the central nervous and hormonal systems. Through complex but carefully balanced feedback mechanisms, the neuroendocrine system regulates sexual function, physical growth and development, appetite and digestion, sleep, heart and kidney function, emotions, thinking, and memory--in other words, multiple functions of the mind and body. Many of these regulatory mechanisms are seriously disturbed in people with eating disorders.
Eating disorders are primarily a medical problem, but anorexia and bulimia do have security overtones. As just discussed under Medical Complications, both are frequently accompanied by other mood, anxiety and personality disorders that may be a security concern. According to the American Psychiatric Association, for example, about one-third of those with bulimia also have a substance abuse problem. From one-third to one-half also have one or more personality disorders, most frequently borderline personality disorder.2
Those who suffer from bulimia are typically ashamed of their eating problems and attempt to conceal them. Their binge eating usually occurs in secrecy. Any out-of-control behavior that a person is ashamed of and seeks to conceal is a potential vulnerability of security concern.
In any case, it cannot be overemphasized how important treatment is -- the sooner, the better. The longer abnormal eating behaviors persist, the more difficult it is to overcome the disorder and its effects on the body. In some cases, long-term treatment may be needed. Families and friends offering support and encouragement can play an important role in the success of the treatment program.
The efforts of mental health professionals need to be combined with those of other health professionals to obtain the best treatment. Physicians treat any medical complications, and nutritionists advise on diet and eating regimens. The challenge of treating eating disorders is made more difficult by the metabolic changes associated with them. Just to maintain a stable weight, individuals with anorexia may actually have to consume more calories than someone of similar weight and age without an eating disorder. In contrast, some normal weight people with bulimia may gain excess weight if they consume the number of calories required to maintain normal weight in others of similar size and age.