Eating disorders are relatively common occurrences in wealthy, industrialized countries, affecting up to 2 percent of women and approximately 0.8 percent of men. They are characterized by a persistent disturbance of eating patterns that leads to poor physical and/or psychological health. The major eating disorders are anorexia nervosa, bulimia nervosa, binge-eating disorder, avoidant/restrictive food intake disorder, pica, and rumination disorder.
Eating is an activity essential to survival, and the body has many built-in mechanisms that regulate appetite and eating. Eating patterns are normally influenced by many factors, environmental as well as biological, and cultural too. The causes of eating disorders are multiply influenced and complex.
Disordered eating patterns can be caused by feelings of distress or concern about body shape or weight, and they harm normal body composition and function. 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 can spiral out of control and the maladaptive patterns of eating take on a life of their own.
Given the complexity of eating disorders, considerable scientific research has been conducted in an effort to understand them, yet the biological, behavioral, and social underpinnings of the illnesses remain elusive. Eating disorders frequently develop during adolescence or early adulthood, but onset during childhood or later in adulthood is not unknown. Many adolescents are able to hide disordered eating behaviors from their family for months or years.
Nevertheless, eating disorders are treatable illnesses. Eating disorders frequently occur together with other psychiatric illnesses, such as depression, substance abuse, or anxiety disorders. In addition, people who suffer from eating disorders can experience a wide range of physical health complications, including serious heart conditions and kidney failure, which may lead to death. The recognition of eating disorders as real and treatable diseases is critically important.
Anorexia nervosa is characterized by persistent restriction on food intake, an intense fear of gaining weight or of becoming fat, and a distorted perception of body weight or shape. An individual with anorexia nervosa maintains a body weight that is below a minimally normal level for age, sex, and physical health.
People with anorexia may lose weight by dieting, fasting, or exercising excessively; they have what is known as the restricting type of anorexia. People who lose weight by self-induced vomiting or misusing laxatives, diuretics, or enemas have the binge-eating/purging type of eating disorder. For a full overview of the symptoms and treatment options for anorexia nervosa, click here.
Bulimia nervosa is characterized by recurrent and frequent episodes of eating unusually large amounts of food (binge-eating) and feeling a lack of control over the eating. This is followed by some type of behavior that compensates for the binge, such as purging (vomiting, excessive use of laxatives or diuretics), fasting, and/or excessive exercise. For a full overview of the symptoms and treatment options for bulimia nervosa, click here.
Binge-eating disorder is characterized by recurrent binge-eating episodes, during which a person feels a loss of control over his or her eating. An episode of binge-eating is defined as eating an amount of food that is definitely larger than most people would eat in a similar period of time under similar circumstances. Unlike bulimia, binge-eating episodes are not followed by purging, excessive exercise, or fasting. As a result, people with binge-eating disorder are often overweight or obese. For a full overview of the symptoms and treatment options for binge-eating disorder, click here.
Avoidant/restrictive food intake disorder (ARFID) is characterized by the avoidance or restriction of food intake. This diagnosis replaced the DSM-IV diagnosis of feeding disorder of infancy or early childhood, and broadened the diagnostic criteria to include adults. Individuals with ARFID have a lack of interest in eating or food, or avoid food based on a past negative experience with the food or the sensory characteristics of the food (appearance, smell, taste, texture, presentation). This form of "picky eating" typically develops in infancy or early childhood and may continue into adulthood. It may also be present in individuals with the heightened sensory sensitivities associated with autism.
ARFID is characterized by significant weight loss, failure to achieve expected weight gain in children, significant nutritional deficiencies, and inability to participate in such mal social activities as eating with others.
Rumination disorder is an eating disorder marked by the repeated regurgitation of food after eating. Individuals with rumination disorder bring up previously swallowed food into the mouth without displaying any signs of nausea, involuntary retching, or disgust. This food is typically then re-chewed and spit out or swallowed again. The regurgitating behavior is sometimes described as habitual or outside of the control of the individual.
The repeated regurgitation of food takes place over a period of at least one month, and it is not a result of an associated gastrointestinal or other medical condition. The disorder is marked by weight loss, and children who have the disorder fail to make expected weight gains. Malnutrition is a prominent feature of the condition. Those affected by rumination disorder typically make attempts to hide the regurgitation behavior by placing a hand over the mouth or coughing. And they avoid eating before social situations, such as work or school
Rumination disorder can develop in infancy, childhood, adolescence, or adulthood. Infants with the disorder tend to strain and arch their back with their head held back, making sucking movements with their tongue. Malnutrition may occur despite ingestion of large amounts of food, particularly when regurgitated food is spit out. In infants as well as in older people with intellectual disability, the regurgitation and rumination behavior seems to have a self-soothing or self-stimulating function, much like other repetitive motor behaviors (such as rocking and head banging).
Pica is characterized by the eating of one or more nonnutritive, nonfood substances on a persistent basis. Substances commonly eaten by people with pica include paper, soap, hair, gum, ice, paint, pebbles, soil, and chalk. People with pica do not typically have an aversion to food in general.
In order for pica to be diagnosed, the behavior of eating nonnutritive, nonfood substances must be present for at least one month. Children below the age of 2 are typically not diagnosed with pica to exclude the developmentally appropriate mouthing of objects by infants that may result in ingestion. People may experience medical complications from pica, such as bowel problems and intestinal obstruction. People may also experience infections if they have eaten feces or dirt. The prevalence of pica is unknown, but it is more prevalent among people with intellectual disability. Some pregnant women also develop pica, with specific cravings for substances such as chalk or ice.
Researchers have long been probing the underlying causes and nature of eating disorders. Unlike a neurological disorder, which generally can be pinpointed to a specific lesion on the brain, an eating disorder likely involves abnormal activity distributed across multiple neural systems.
Eating disorders appear to run in families, and there is ongoing research on genetic contributions to the conditions. Other factors—psychological, interpersonal, and social—can play a role in eating disorders. Among identified psychological factors are low self-esteem, feelings of inadequacy and lack of control in life, depression, anxiety, anger, and loneliness.
Interpersonal factors include troubled family and personal relationships, difficulty expressing emotions and feelings, a history of being teased or ridiculed based on size and weight, or a history of physical or sexual abuse. Social factors that can contribute include cultural pressures that glorify thinness and place value on obtaining the "perfect" body, narrow societal definitions of beauty that include only those people of specific body weights and shapes, or cultural norms that value people on the basis of physical appearance and not inner qualities and strengths.
People with anorexia nervosa see themselves as overweight even though they may be dangerously thin. In bulimia nervosa, despite usually weighing within the normal range for their age and height, sufferers, like individuals with anorexia, may fear gaining weight, desire to lose weight, and feel intensely dissatisfied with their bodies. Many with binge-eating disorders are overweight for their age and height. Feelings of self-disgust and shame associated can lead to bingeing again, creating a cycle of binge-eating.
Eating disorders can be treated, and a healthy weight can be restored. The sooner an eating disorder is diagnosed and treated, the better the outcome is likely to be. Because of their complexity, eating disorders require a comprehensive treatment plan involving medical care and monitoring, professional interventions, nutritional counseling, psychotherapy, and, when appropriate, medication management.
The treatment of anorexia calls for a specific program that involves four main phases: restoring the person to a healthy weight lost to severe dieting and purging; treating psychological disturbances, such as distortion of body image, low self-esteem, and interpersonal conflicts; reducing or eliminating behaviors or thoughts that lead to disordered eating; and preventing relapse.
Some research suggests that the use of medications, such as antidepressants, antipsychotics, or mood stabilizers, may be modestly effective in treating patients with anorexia by helping to resolve mood and anxiety symptoms that often co-exist with anorexia.
Different forms of psychotherapy, including individual, group, and family-based, can help address the psychological issues underlying anorexia nervosa. Some studies suggest that family-based therapies, in which parents assume responsibility for feeding their eating-disordered adolescent, are the most effective in helping a person with anorexia gain weight and improve eating habits and moods. There is some evidence that a combined approach of medical attention and supportive psychotherapy designed specifically for anorexia patients is more effective than psychotherapy alone. The effectiveness of treatment depends on the unique situation of each patient.
Hospital-based care (including inpatient, partial hospitalization, intensive outpatient, and/or residential care in a special eating disorders specialty unit or facility) is necessary when an eating disorder has led to physical problems that may be life-threatening or when it is associated with severe psychological or behavioral problems.
The course and outcome of anorexia nervosa vary across individuals; some fully recover after a single episode, some fluctuate between weight gain and relapse, and others chronically deteriorate over many years.
The mortality rate among people with anorexia has been estimated at .56 percent per year which is about 12 times higher than the annual death rate due to all causes of death among females ages 15 to 24 in the general population. The most common causes of death are complications of the disorder, such as cardiac arrest, electrolyte imbalance, and suicide.
The primary goal of treatment for bulimia is to reduce or eliminate binge-eating and purging behavior. Nutritional rehabilitation, psychological intervention, and medication management are often employed. As with anorexia, treatment for bulimia often involves a combination of options and is usually based on the needs of the individual.
To reduce or eliminate binge-and-purge behavior, a patient may undergo nutritional counseling and psychotherapy, especially cognitive behavioral therapy (CBT), or be prescribed medication. Some antidepressants, such as the SSRI fluoxetine (Prozac), can be used to treat eating disorders and may help patients who also have depression and/or anxiety. Medication can also help reduce binge-eating and purging behavior, reduce the chance of relapse, and improve eating attitudes. CBT that has been tailored to treat bulimia has also been shown to be effective in changing bingeing-and-purging behavior and eating attitudes. Therapy may be individually oriented or group-based.
The treatment goals and strategies for binge-eating disorder are similar to those for bulimia. Fluoxetine and other antidepressants may reduce binge-eating episodes and help alleviate depression in some patients. Patients with binge-eating disorder may also be prescribed appetite suppressants. Psychotherapy, especially CBT, in an individual or group environment, is also used to treat the underlying psychological issues associated with binge-eating.
People with eating disorders often do not recognize or admit that they are ill. As a result, they may strongly resist getting and staying in treatment. Family members or other trusted individuals can be helpful in ensuring that the person with an eating disorder receives needed care and rehabilitation.