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Eating disorders

What is an Eating Disorder?

Eating a balanced and healthful diet is crucial for the normal functioning of all organ systems. Disordered eating habits (e.g., skipping meals) or prolonged dieting (e.g., calorie restriction) may deplete the body of important nutrients and can lead to malnutrition. In some cases, such habits may become chronic and may lead to the development of an eating disorder.

Eating disorders involve serious disturbances in eating behavior, including unhealthy reduction of food intake or severe overeating, in addition to extreme unhappiness or concern about body shape and weight. Oftentimes, individuals with eating disorders (e.g., anorexia nervosa, bulimia nervosa) associate their self-worth or self-esteem with the way their bodies look and attempt to control their weight through harmful methods such as starvation and purging (e.g., self-induced vomiting). In some cases, people may feel no self-control when it comes to food and may gorge themselves until they are uncomfortably full (binge eating).

Generally, eating disorders co-exist with other psychological disorders including depression, anxiety disorders (e.g., obsessive-compulsive disorder) and substance abuse. Females are more likely than males to develop eating disorders. According to the U.S. Department of Health and Human Services, more than 90 percent of patients with eating disorders are female. Eating disorders typically begin during adolescence or early adulthood. However, in some cases they may develop before adolescence as well as during middle age (at age 40 or older). Eating disorders are more common in industrialized, economically developed nations. Currently, between 1 and 4 percent of all young women in the United States have some type of eating disorder.

Eating disorders are dangerous because food is vital for sustaining all bodily functions. Individuals with prolonged eating disorders may develop malnutrition that can become life-threatening if left untreated. Oftentimes, people with eating disorders are in denial and do not recognize or admit that there may be a problem and as a result, may become extremely resistant to seeking medical treatment. In such cases, the intervention of family members, teachers or peers may be necessary to ensure that the individual suspected of having an eating disorder receives proper medical attention.

Types and differences of eating disorders

Eating disorders are generally characterized by an obsessive preoccupation with weight and/or food that results in extreme disturbances in eating and other behaviors. These disorders are often chronic and dangerous because they can severely compromise a person’s health.

The three most common types of eating disorders include:

Anorexia nervosa

This eating disorder is basically self-starvation. To be diagnosed with anorexia nervosa, a person must weigh more than 15 percent below the normal range for their age and body size and exhibit a distorted body image, including a sometimes intense fear of gaining weight. People with anorexia nervosa usually lose weight by drastically reducing their food intake (fewer than 1,000 calories per day) and through excessive exercise (anorexia athletica). Among adolescents, anorexia may also be present when a person fails to gain age-appropriate weight during puberty and post-puberty, even if he or she is not losing much weight. According to the U.S. Department of Health and Human Services, it ranks as the third most common chronic illness among adolescent girls in the nation.

Anorexia nervosa has severe, life-threatening complications. Prolonged starvation can lead to malnutrition and damage of the vital organs, including the heart and brain. In addition, nutritional deprivation often results in the loss of bone mass (osteoporosis), which may result in brittle bones that break easily. Other complications include amenorrhea (loss of menstrual periods), anemia (low red blood cell count), hair loss, infertility (inability to get pregnant) and a failure to grow to normal stature in children or adolescents. If left untreated, patients with anorexia nervosa may literally starve themselves to death.

Bulimia nervosa

Also called bulimia or binge-purge syndrome, this eating disorder is characterized by a pattern of binge eating followed by harmful behaviors to control or prevent any resulting weight gain. Binge eating is defined as the consumption of excessive amounts of food in a short time period. The food is often high in calories and easy to consume (e.g., ice cream). Typically, people with bulimia purge themselves of eaten food by either self-induced vomiting or the use of laxatives (usually mild drugs for stimulating bowel movement), diuretics or, rarely, enemas (injecting liquid into the intestines through the anus to empty the bowels). To be diagnosed with bulimia, these types of behaviors must have occurred on average a minimum of two times a week for three months.

Patients with bulimia nervosa may cause harm to their bodies with frequent episodes of binging and purging. Complications of bulimia include electrolyte imbalance (a loss of vitamins and minerals that are crucial for normal organ functioning, such as potassium) and dehydration (loss of water), which may lead to weakness and irregular heart rhythms. Other complications include tooth and gum decay caused by the acids contained in the vomit, digestive problems (e.g., constipation) and medication abuse (e.g., diuretics, stimulants, diet pills). In prolonged or severe cases, binge eating may cause the stomach to rupture and chronic purging may result in heart failure.

Binge eating disorder (BED)

This disorder, which is a research diagnosis is not yet fully accepted, is mainly identified by recurring episodes of uncontrolled, rapid eating, often followed by remorse and guilt. The binging or overeating typically does not stop until the person is uncomfortably full, and the person usually eats alone because of embarrassment. BED differs from anorexia nervosa and bulimia nervosa in that it is not associated with purging behaviors (e.g., self-induced vomiting, use of laxatives) to avoid the weight gain. However, individuals with this type of eating disorder sometimes may engage in chronic dieting attempts and/or fasting. Also, BED may sometimes be difficult to differentiate from overweight or obesity. Individuals with BED often feel out of control when it comes to their binges and have accompanying feelings of depression, guilt and self-disgust.

Complications of binge eating disorder include obesity, high blood pressure, high cholesterol levels, heart disease, type 2 diabetes (uncontrolled blood sugar) and gallbladder disease (inflammation or infection of the sac gallbladder, which helps digest fats).

How is it diagnosed?

Physicians generally diagnose eating disorders based on the patient’s symptoms and eating habits. During an initial consultation, a physician will record the patient’s weight and perform a thorough physical examination including:

  • Checking vital signs, such as heart rate, blood pressure and temperature
  • Evaluation of patient’s skin, abdomen and teeth
  • Neurological examination to evaluate other potential causes of weight loss or vomiting, such as a brain tumor
A physician will also compile a comprehensive medical history including family history of physical and psychological disorders (e.g., depression, obsessive-compulsive disorder) as well as inquire into the patient’s history of dieting and/or eating patterns. Some of the questions a physician may ask include:
  • Have you recently lost more than 14 pounds (6.35 kg) in a three-month period?
  • Do you believe you are fat when others say you are too thin?
  • Would you say that food dominates your life?
  • Do you make yourself sick because you feel uncomfortably full?
  • Do you ever eat in secret?
  • Does your weight affect the way you feel about yourself?
In addition, a physician may order diagnostic tests to identify any signs of complications of eating disorders including malnutrition, anemia (reduced blood cell count), unusual heart rhythms, digestive problems (e.g., constipation, diarrhea), bone density loss or changes in the menstrual cycle.

Additional diagnostic tests may include:

Blood tests

Laboratory analyses – including a complete blood count (CBC) – of blood samples to measure levels of hormones, enzymes, proteins, electrolytes, vitamins and other substances. Blood tests assess the function of various organ systems including the liver, kidney, thyroid and pituitary glands as well as the ovaries (female reproductive glands).


Chemical examination of a patient’s urine sample to screen for urinary tract infections, kidney disease and diseases of other organs that result in the appearance of abnormal metabolites (break-down products) in the urine.

Electrocardiogram (EKG)

This test measures the pattern of electrical impulses generated by the heart. During the procedure, electrodes (devices that detect electrical impulses) are attached to the patient’s chest. The electrical impulses are then recorded on a graph. In patients with eating disorders, an EKG can help detect irregular heartbeats and identify the presence of any damage to the heart.

Imaging tests

These tests (e.g., x-ray, CAT scan, MRI) are useful in detecting the presence of any damage in the chest, digestive tract, brain and other organs caused by eating disorders. For example, a chest x-ray may reveal whether the eating disorder has damaged the heart muscles by reducing the size of the heart.

Bone density test

During this test, a physician may use a device called a sonometer to pass painless sound waves through the bones to measure the density of the bones and check for signs of bone mass loss (osteoporosis).
Once an eating disorder is diagnosed, a physician may refer the patient to a mental and/or behavioral health specialist (typically a psychiatrist) for further evaluation and treatment. Patients may also be referred to a nutritionist (a licensed nutrition expert) and/or dentist for the treatment of dental complications, such as tooth and gum decay.

How is Eating Disorder treated?

The sooner an individual with an eating disorder is diagnosed and begins treatment, the better the outcome is likely to be. Due to their complexity, eating disorders usually require a comprehensive treatment plan including medical care and monitoring of health complications (e.g., malnutrition, obesity), psychological evaluation, behavior therapy and dietary counseling. In severe cases of malnutrition, immediate hospitalization of the patient may be necessary to rehydrate and restore electrolyte imbalance through intravenous (into a vein) feeding.

Often, people with eating disorders are in denial and may refuse to recognize that there is a problem. Many times, they may resist getting and staying in treatment. Family members and other individuals close to the person suspected of having an eating disorder are urged to ensure that they receive needed care and rehabilitation. For some patients, medical treatment may be long term.

Eating disorders generally require a multi-disciplinary approach for rehabilitation that often includes:

Nutritional counseling. Regular consultation with a nutritionist (licensed nutrition specialist) or registered dietitian is important for patients with eating disorders. Nutrition experts may help patients gain a fundamental understanding of adequate nutrition including the importance of a healthy, well-balanced diet. These specialists also conduct dietary counseling, which can help patients change the nature of their eating behavior.

In the case of anorexia nervosa, a nutritionist may initially set the patient on an eating plan for gradual weight gain. This is done to prevent any harm to the body, especially the heart, from a rapid increase in weight. Typically, patients might be expected to gain 2–3 pounds a week for patients at an inpatient facility and 0.5–1 pound a week for outpatients. In the case of bulimia and binge eating disorder, a nutritionist may assist in establishing a pattern of regular, non-binge meals.
Psychotherapy (e.g., cognitive behavioral therapy [CBT], family therapy). These types of therapy will address and help treat psychological disturbances including distortion of body image, low self-esteem and interpersonal conflicts associated with eating disorders.
Drug therapy (psychotropic medications, such as antidepressants). Antidepressants, such as the selective serotonin reuptake inhibitors (SSRIs), have been found helpful in treating eating disorders that co-exist with other types of emotional disorders, especially depression and anxiety disorders. Psychotropic medications may also help prevent relapse of eating disorders. Patients should be aware that a physician may need to adjust the dosage or change medications to achieve the best results with minimal side effects. In addition, the U.S. Food and Drug Administration has advised that antidepressants may increase the risk of suicidal thinking in some patients, especially adolescents, and all people being treated with them should be monitored closely for unusual changes in behavior.

Since psychotherapy (e.g., CBT) appears more effective than medication for anorexia nervosa, use of medication in people with anorexia nervosa is usually offered as an adjunctive treatment to, and not a replacement for, psychotherapy. Medication treatment may pose additional risks among this population because of their low body weight, irregular heartbeat and electrolyte imbalance.
Patients with eating disorders are urged to have regular check-ups with their physician to monitor their overall health and treat any complications, such as cardiac arrhythmia (irregular heartbeat). Some patients with severe anorexia may experience diet-related complications as they gain weight and their metabolism shifts. This is known as refeeding syndrome, and it may involve electrolyte problems. These patients are usually closely monitored for electrolyte levels.

Sometimes, residential care that involves the patient remaining in a facility that specializes in treating eating disorders may be necessary, especially in the case of chronic relapses or when patients have not been able to reach a significant degree of medical and psychological stability from their initial treatment plans.

Patients with dental problems (e.g., tooth and gum decay) resulting from eating disorders may be referred to the care of a dentist (dental health specialist) for treatment.

People with eating disorders may also benefit greatly from participating in support groups to prevent relapse as well as help cope with their condition. Physicians and mental health professionals can provide patients with information regarding support groups for people with eating disorders.


Generic Amitriptyline

Prozac (Fluoxetine), Tofranil (Imipramine), Periactin (Cyproheptadine)

What might complicate it?

There are any number of severe complications, many of them serious.

Those seen more commonly in anorexia are absence of menstrual cycling and other glandular problems, malnutrition, and severe imbalances in blood chemistry, which can cause irregular heartbeat, seizures, coma, and death.

Muscle wasting, kidney failure, problems due to poor liver function and superior mesenteric artery syndrome are other possible complications, as well as significant weight loss to less than 75% of normal, which is a very dangerous condition and can lead to medical hospitalization.

Bulimics also run the risk of severe blood chemistry imbalances and the associated complications as well as rupture of the stomach or esophagus and advanced dental decay. Depression, irritability, insomnia, and generally poor mental functioning are some of the more common psychological complications.

These disorders share in common many features of drug and alcohol abuse, so it is not surprising that these illnesses often co-occur in these individuals. This vastly complicates treatment as the individual "trades" addictions.

Predicted outcome

Over a five-year span, approximately one-third of individuals will have a complete or near complete remission of their symptoms, one-third will show significant improvement, while the remaining one-third either fail to improve or deteriorate. Mortality is significant. Anorexia nervosa has a mortality rate of four or five percent, but some studies place it as high as twenty percent. Because these disorders are usually quite complicated, it is difficult to predict the outcome. Generally, the younger the age at which the symptoms appear, the poorer the prognosis.


Two of the more common psychiatric syndromes that may be mistaken for these eating disorder are depression and schizophrenia. Another psychiatric illness often present, as well, is that of obsessive-compulsive disorder. Borderline personality disorder may have many of the same behaviors. Generally, a good history taken by a trained psychiatrist is sufficient to exclude these other conditions. Physical causes such as brain tumors and other types of cancer, infections, and glandular problems need to be excluded through physical and laboratory tests.

Appropriate specialists

Psychiatrist, psychologist, or other licensed mental health worker, registered dietitian, nurse practitioner, and internist.

Last updated 8 July 2015