Eating disorders are characterized by a persistent disturbance of eating patterns that lead to poor physical or psychological health. The major eating disorders are pica, rumination disorder, avoidant/restrictive food intake disorder, anorexia nervosa, bulimia nervosa, and binge-eating disorder.
Eating disorders happen as a result of severe disturbances in eating behavior, such as unhealthy reduction of food intake or extreme overeating. These feeding 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.
Eating disorders are very complex, and despite scientific research to understand them, the biological, behavioral, and social underpinnings of these illnesses remain elusive. Eating disorders frequently develop during adolescence or early adulthood, but some reports indicate their onset can occur during childhood or later in adulthood. Many adolescents are able to hide these behaviors from their family for months or years.
Eating disorders are not due to a failure of will or behavior; rather, they are real, treatable medical illnesses in which certain maladaptive patterns of eating take on a life of their own. Eating disorders frequently occur together with other psychiatric illness 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. 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 distortion of body weight or shape. An individual with anorexia nervosa will maintain a body weight that is below a minimally normal level for age, sex, and physical health.
Some people with anorexia lose weight by dieting, fasting, or exercising excessively; this is called the restricting type of anorexia. Others lose weight by self-induced vomiting or misusing laxatives, diuretics, or enemas. People who use these methods are considered to have the binge-eating/purging type of anorexia. More characteristics of anorexia nervosa include:
- Significant weight loss
- Continual dieting
- Intense fear of gaining weight or becoming fat, even if underweight
- Undue influence of body weight or shape on self-evaluation
- Preoccupation with calories or nutrition
- Preference to eat alone
- Compulsive exercise
- Bingeing and purging
- Brittle hair or nails
- Infrequent or absent menstrual periods (in females who have reached puberty)
- Growth of fine hair over body
- Mild anemia, and muscle weakness and loss
- Severe constipation
- Low blood pressure, slowed breathing and pulse
- Drop in internal body temperature, causing a person to feel cold all the time
Some people with anorexia nervosa feel they are overweight in all areas of their body, while others may recognize that they are thin but are concerned that certain body parts are "too fat," such as their abdomen or buttocks. They may use many different techniques to evaluate their body size or weight, such as frequent weighing and obsessive measuring of body parts. Additionally, the self-esteem of individuals with anorexia is closely tied to their perceptions of their body shape and weight. Weight gain is often viewed as a major failure, while weight loss is an impressive achievement.
Many people with anorexia have coexisting psychiatric and physical illnesses, including depression, anxiety, obsessive behavior, substance abuse, cardiovascular and neurological complications, and impaired physical development. The semi-starvation state of anorexia can also result in serious and potentially life-threatening conditions. The 12-month prevalence of anorexia among young females is estimated to be 0.4 percent.
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. Unlike individuals with anorexia nervosa, people with bulimia maintain body weight at or above a minimally normal level. Additional symptoms include:
- Recurrent episodes of binge eating
- Purging by strict dieting, fasting, vigorous exercise, or vomiting
- Abuse of laxatives or diuretics to lose weight
- Frequent use of bathroom after meals
- Reddened fingers
- Swollen cheeks
- Self-evaluation that is unduly influenced by body shape and weight
- Depression or mood swings
- Irregular menstrual periods
- Dental problems, like tooth decay
- Heartburn or bloating
- Intestinal distress and irritation from laxative abuse
- Kidney problems from diuretic abuse
- Severe dehydration from purging of fluids
People with bulimia tend to feel embarrassed or ashamed of their eating behaviors and try to hide their symptoms by binge eating in secrecy. The most common triggers for binge eating are negative affect (e.g. sadness, fear, guilt), interpersonal stressors (e.g. arguments), inadequate food intake, negative feelings about body weight or shape, and boredom. The 12-month prevalence of bulimia among young females is estimated to be 1.5 percent.
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. Community surveys have estimated that 1.6 percent of females and 0.8 percent of males experience binge-eating disorder in a twelve-month period.
Characteristics of binge-eating disorder include:
- Binge-eating occurring, on average, at least once a week for six months
- Eating much more rapidly than normal
- Eating until feeling uncomfortably full
- Eating large amounts of food when not hungry
- Eating alone because of embarrassment caused by how much is eaten
- Feeling disgusted with oneself, depressed, or guilty after binge eating
- Marked distress about the binge-eating behavior
- Binge-eating not associated with regular use of compensatory behaviors (purging, fasting, excessive exercise)
Avoidant/Restrictive Food Intake Disorder
Avoidant/restrictive food intake disorder (ARFID) is characterized by the avoidance or restriction of food intake. This diagnoses replaces 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 (e.g., 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 heightened sensory sensitivities associated with autism.
Characteristics of ARFID include:
- Significant weight loss
- Failure to achieve expected weight gain in children
- Significant nutritional deficiency
- Inability to participate in normal social activities, such as eating with others
Rumination disorder is characterized by repeated regurgitation of food after eating. Individuals with this 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.
Characteristics of rumination disorder include:
- Repeated regurgitation of food over a period of at least one month
- The repeated regurgitation is not a result of an associated gastrointestinal or other medical condition
- Weight loss and failure to make expected weight gains in children
- Attempts to hide the regurgitation behavior by placing a hand over the mouth or coughing
- Avoidance of 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 (i.e. rocking, head banging).
Pica is characterized by the eating of one or more nonnutritive, nonfood substances on a persistent basis. Some of the substances commonly eaten among 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 two 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 when specific cravings such as chalk or ice occur.
Researchers are unsure of 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 neural systems. With increased recognition that mental disorders are brain disorders, more researchers are using tools from both modern neuroscience and modern psychology to better understand eating disorders. Additionally, eating disorders appear to run in families so research on genetic factors continues.
Other factors—psychological, interpersonal, and social—can play a role in eating disorders. Psychological factors that can contribute to eating disorders include low self-esteem, feelings of inadequacy or lack of control in life, depression, anxiety, anger, or 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 women and men 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 are dangerously thin. In bulimia nervosa, despite their 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 with this illness 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 these disorders are diagnosed and treated, the better the outcomes are likely to be. Because of their complexity, eating disorders require a comprehensive treatment plan involving medical care and monitoring, professional interventions, nutritional counseling, and, when appropriate, medication management.
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 reasons for anorexia nervosa. Some studies suggest that family-based therapies, in which parents assume responsibility for feeding their afflicted adolescent, are the most effective in helping a person with anorexia gain weight and improve eating habits and moods. Others have noted 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 an 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, professional intervention, and medication management are often employed. As with anorexia, treatment for bulimia often involves a combination of options and depends 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 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.
- American Psychiatric Association, Diagnostic and Statistical Manual, Fifth Edition
- National Institutes of Health
- National Eating Disorders Association
Last reviewed 02/07/2019