Eating disorders (EDs) are psychological disorders characterized by abnormal eating patterns that may have a negative effect on health status.
The National Comorbidity Survey Replication study reported that lifetime prevalence rates for anorexia nervosa are about 0.3% in men and 0.9% in women; for bulimia nervosa, 0.5% in men and 1.5% in women; and for binge eating disorder, 2% in men and 3.5% in women in the United States. In general, more women have eating disorders than men, and according to the National Eating Disorder Association; an estimated 10 million females in the United States have some form of eating disorder. The age of onset of an ED differs by disorder. Anorexia nervosa and bulimia nervosa typically begin during adolescence, while binge eating can start well into adulthood. Research reports show an increasing trend in EDs among middleaged women. Long-term studies have documented that 12% of adolescent girls aged 12 to 15 years have experienced some form of ED. Anorexia athletica, muscle dysmorphic disorder, and orthorexia nervosa tend to be more common in men. Rumination, pica, and Prader-Willi syndrome occur in childhood and adulthood and affect males and females equally.
Anorexia nervosa begins primarily between the ages of 14 and 18 and affects mainly white girls. Bulimia usually develops slightly later, in the late teens and early twenties. Binge eating disorder can manifest in middle age and affect blacks and whites equally. Prader-Willi syndrome begins in the toddler years. Demographic data such as age, gender, and race are not available for anorexia athletica, muscle dysmorphic disorder, and orthorexia nervosa.
Symptoms of eating disorders
Binge eating disorder
Resistance to maintaining body weight at or above a minimally normal weight for age and height
Intense fear of gaining weight or becoming fat, even though underweight
Disturbance in the way in which one's body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or denial of the seriousness of the current low body weight
Infrequent or absent menstrual periods (in females who have reached puberty)
Recurrent episodes of binge eating, characterized by eating an excessive amount of food within a discrete period of time and by a sense of lack of control over eating during the episode
Recurrent inappropriate compensatory behavior in order to prevent weight gain, such as self-induced vomiting or misuse of laxatives, diuretics, enemas, or other medications (purging); fasting; or excessive exercise
The binge eating and inappropriate compensatory behaviors both occur, on average, at least twice weekly for three months
Self-evaluation is unduly influenced by body shape and weight
Recurrent episodes of binge eating, characterized by eating an excessive amount of food within a discrete period of time and by a sense of lack of control over eating during the episode
The binge-eating episodes are associated with at least three of the following: eating much more rapidly than normal; eating until feeling uncomfortably full; eating large amounts of food when not feeling physically hungry; eating alone because of embarrassment by how much one is eating; feeling disgusted, depressed, or very guilty after overeating
Marked distress about the binge-eating behavior
The binge eating occurs, on average, at least two days a week for six months
The binge eating is not associated with the regular use of inappropriate compensatory behaviors (e.g., purging, fasting, excessive exercise)
SOURCE: National Institute of Mental Health. National Institutes of Health. “Eating Disorders.” U.S. Department of Health and Human Services. https://www.nimh.nih.gov/health/topics/eating-disorders/index.shtml#part_145414 (accessed April 2, 2018).
Three well-known eating disorders, anorexia nervosa, bulimia nervosa, and binge eating are recognized as psychiatric disorders in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, or DSM-5, published by the American Psychiatric Association (APA). Although other eating disorders have recognized sets of symptoms, they are not yet defined by the APA as separate psychiatric disorders.
Anorexia nervosa is the most recognized eating disorder in North America and Europe. It gained widespread public attention with the rise of the ultrathin fashion model. People with anorexia nervosa are obsessed with body weight and may see themselves as overweight even when they are underweight. They constantly monitor their food intake and starve themselves to become thin. No matter how much weight they lose, they continue to restrict calorie intake in an effort to become ever thinner. Some people with anorexia tend to overexercise or abuse drugs or herbal remedies that they believe will help them burn calories faster. Some may purge their bodies of the few calories they do eat by abusing laxatives, enemas, and diuretics. In time, they reach a point where their health is seriously, and potentially fatally, impaired. Suicide is more common among individuals with anorexia nervosa than among those with other psychological disorders. Many vigorously resist treatment and accuse anyone trying to cure them of wanting to make them fat. Recovery is long and difficult.
Bulimia nervosa refers to the consumption of unreasonably large amounts of food in a short time and then purging the body of calories, usually by self-induced vomiting. Purging is often accompanied by laxative abuse. Other individuals with bulimia do not vomit after eating, and instead fast and exercise obsessively to burn calories. Although both behaviors impair overall health status, individuals with bulimia are usually of normal weight. They also recognize their abnormal behavior and feel out of control when they are binge eating. Often they are ashamed and feel guilty about their behavior and will go to great lengths to hide their binge/purge cycles from family and friends. Although their behavior results in negative health consequences, the consequences are less likely to be life-threatening because the individuals are not severely underweight.
Binge eating is newly recognized in the DSM-5 as an eating disorder. However, it must occur at least twice a week for three months or more. People with binge eating disorder may eat thousands of calories in an hour or two. While they are eating, they feel out of control and may continue to eat long after they feel full. They may feel ashamed of their behavior and may try to hide it by eating in secret or hoarding food for future binges. After a binge, they usually feel guilty about their eating behavior and might promise themselves they will never binge again but are usually unable to keep this promise. The cycle of rigorous dieting followed by an eating binge followed by guilt is repeated over and over again. Unlike bulimia, people with binge eating disorder do not purge or exercise to burn the calories they have eaten. As a result, many people with binge eating disorder are obese, and the main health consequences are the development of obesity-related diseases such as type 2 diabetes, sleep apnea, stroke, and heart attack.
Several abnormal eating behaviors are called disorders even though they do not have formal diagnostic criteria. They fall under the APA definition of eating disorders not otherwise specified. Many have only recently come to the attention of researchers and have been the subject of only a few small studies. Some have been known to the medical community for years but are rare.
Purge disorder is thought by some experts to be a separate disorder from bulimia. It is distinguished from bulimia by the fact that the individual maintains a normal or near normal weight despite purging by vomiting or abuse of laxatives, enemas, or diuretics.
Anorexia athletica is a disorder of compulsive exercising. The individual places exercise above work, school, or relationships and defines his or her self-worth in terms of athletic performance. People with anorexia athletica also tend to be less obsessed with body weight than with maintaining an abnormally low percentage of body fat. This disorder is common among elite athletes.
Orthorexia nervosa is a term coined by Steven Bratman, a Colorado physician, to describe “a pathological fixation on eating ‘proper,’ ‘pure,’ or ‘superior’ foods.” People with orthorexia allow their fixation with eating the correct amount of properly prepared healthy foods at the correct time of day to take over their lives. This obsession interferes with relationships and daily activities. For example, an individual with orthorexia may be unwilling to eat at restaurants or at the homes of friends because the food is impure or improperly prepared. Limitations placed on what they will eat can cause serious vitamin and mineral imbalances. People with orthorexia also may be judgmental about what other people eat to the point that it interferes with personal relationships. They justify the fixation by claiming that their way of eating is healthy. Some experts believe orthorexia may be a variation of obsessive-compulsive disorder.
Rumination syndrome refers to the voluntary or involuntary regurgitation of food almost immediately after swallowing it. The individual with rumination syndrome may then chew the regurgitated food and either swallow it or spit it out. Regurgitation syndrome is the human equivalent of a cow chewing its cud. The behavior may last up to two hours after eating and must continue for at least one month to be considered a disorder. Occasionally the behavior simply stops on its own, but may also last for years.
Pica is the eating of nonfood substances by people past the developmental stage where such eating is considered normal (usually around age two). Earth and clay are the most common nonfoods eaten, which has been thought to occur as a result of iron deficiency. People also have been known to eat hair, feces, lead, laundry starch, chalk, burnt matches, cigarette butts, light bulbs, and other equally bizarre nonfoods. This disorder has been known to the medical community for years, and in some cultures (mainly tribes living in equatorial Africa) is considered normal. Pica is more common among people with intellectual disability and developmental delays. It only rises to the level of a disorder when health complications require medical treatment. Pregnant women and preadolescents are at the highest risk of pica; the condition has been linked to nutrient deficiencies such as iron and zinc deficiencies.
Prader-Willi syndrome is a genetic defect that spontaneously arises in chromosome 15. It causes low muscle tone, short stature, arrested sexual development, intellectual disability, and an uncontrollable urge to eat. People with Prader-Willi syndrome never feel full. The only way to stop them from eating themselves to death is to keep them in an environment where food is locked up and not available. Prader-Willi syndrome is a rare disease, and although it is caused by a genetic defect tends not to run in families, but rather is an accident of development. Fewer than 15,000 people in the United States have Prader-Willi syndrome.
“Drunkorexia,” though not a medically recognized diagnosis, is the restriction of calories from food in order to consume greater amounts of alcohol without gaining weight. The U.S. Centers for Disease Control and Prevention (CDC) defines binge drinking as having more than five drinks for men or four drinks for women in a relatively short timeframe. It is associated with adverse health effects such as higher risk of alcohol dependence, high blood pressure, stroke, heart disease, liver disease, neurological damage, sexual dysfunction, injury (intentional or unintentional), and sexually transmitted diseases (due to lowered inhibitions while drunk). Replacing meals with alcohol may increase the risk of vitamin and nutrient deficiencies and malnutrition.
Depression, low self-worth, and anxiety disorders are all common among people with eating disorders. Some disorders have obsessive-compulsive elements. Although the associations between these psychiatric disorders and eating disorders are strong, the cause and effect relationship is still unclear. Most specialists agree that eating disorders have multiple causes, including genetic predisposition. Individual biochemical patterns may also play a role. For example, one function of brain neurotransmitters (e.g., serotonin, norepinephrine) is to help regulate appetite. Abnormalities in the amounts of some neurotransmitters are thought to play a role in anorexia, bulimia, and binge eating disorder. Other disorders have not been studied enough to draw any conclusions.
Personality disorders may also increase risk for developing an eating disorder. Low self-worth is common among people with eating disorders. Binge eaters and people with bulimia tend to have problems with impulse control and anger management. A tendency toward obsessive-compulsive behavior and black-or-white, all-or-nothing thinking also increases the risk of developing an eating disorder.
Research has documented that comorbid illnesses and eating disorders tend to be diagnosed as a cluster of diagnoses; that is, patients with eating disorders often experience other psychiatric disorders. Axis I psychiatric disorders (including depression, anxiety, body dysmorphic disorder, or chemical dependency) and Axis II personality disorders (particularly borderline personality disorder) are frequently found among individuals with eating disorders. The extent of these conditions increases the complexity of treatment and the skill required of the counselors and medical providers providing treatment.
Diagnosis of an eating disorder involves four components: a personal and family medical history, a physical examination to rule out hormone abnormalities that may result in weight loss, laboratory tests, and a mental status evaluation that also assesses suicidal risk. Personal health histories tend to be unreliable, because many people with eating disorders lie about their eating behavior, purging habits, and medication abuse. The goal of evaluation is to get an accurate assessment of the individual's physical condition and attitudes toward self-worth, body image, and food.
During the physical examination, other medical conditions may be diagnosed as well, including cardiac arrhythmia, dehydration and electrolyte imbalances, delayed growth and development, endocrinological disturbances, gastrointestinal problems, oral health problems, osteopenia, osteoporosis, and protein/calorie malnutrition.
The mental health examination involves the use of several validated scales and relies on the DSM-V for diagnostic criteria that define the eating disorders. The diagnostic criteria for anorexia nervosa, for example, includes an exaggerated drive for thinness, refusal to maintain a body weight above the standard minimum (e.g., 85% of expected weight), intense fear of becoming fat with self-worth based on weight or shape, evidence of an endocrine disorder, restricted energy intake relative to requirements (leading to a markedly low body weight), intense fear of gaining weight or becoming fat or persistent behavior to avoid weight gain, and considerable distress regarding one's weight or body shape.
Criteria for bulimia nervosa include overwhelming urges to overeat and inappropriate compensatory behaviors or purging following the binge episodes (e.g., vomiting, excessive exercise, alternating periods of starvation, and abuse of laxatives or drugs), recurrent episodes of binge eating with a sense of a lack of control and inappropriate compensatory behavior, self-evaluation that is unduly influenced by body shape and weight, and specification that the behaviors do not occur exclusively during episodes of anorexia nervosa.
Eating disorders that have not been classified as disorders are described as compensatory behaviors distinguished by binge eating and lack of self-control. Binge eating, however, is recognized as an eating disorder in DSM-5. The diagnostic criteria specify that binge eating involves eating more rapidly, eating until feeling uncomfortable, eating large amounts of food, eating alone because of embarrassment at the quantity consumed, and feeling disgusted with oneself, depressed, or guilty afterwards.
Treatment depends on a collaborative approach by an interdisciplinary team of mental health, nutrition, and medical specialists. The degree to which the individual's health and mental status is impaired can direct what type of treatment plan is appropriate for the individual. Some individuals with eating disorders may need to be hospitalized or attend a structured day program for an extended period. Although medications will also be prescribed for some people, the mainstay of treatment is psychotherapy. An appropriate therapy is selected based on the type of eating disorder and the individual's psychological profile. Some of the common therapies used in treating eating disorders include:
No medications are approved by the U.S. Food and Drug Administration (FDA) for the specific treatment of eating disorders, although the FDA has included bulimia as an indication for fluoxetine (Prozac, Sarafem), a selective serotonin reuptake inhibitor (SSRI) antidepressant. Medications prescribed for those with anorexia nervosa focus on either reducing anxiety or alleviating mood symptoms to assist the person in eating. SSRI antidepressants, including fluoxetine and sertraline (Zoloft), are sometimes prescribed for anorexia nervosa and binge eating as well as bulimia. These antidepressants are shown to reduce binge eating and improve mood in depressed or anxious patients with eating disorders.
Eating disorders sometimes result in malnutrition that may have life-threatening consequences. Death may occur due to cardiac arrhythmia, acute cardiovascular failure, gastric hemorrhaging, or suicide. Nutrition inadequacies commonly seen among those with eating disorders are low energy intake (which can be as severe as eating fewer than 500 calories per day), protein intake that results in clinical signs of protein deficiency, insufficient dietary calcium intake, fluid and electrolyte imbalances, and an array of vitamin and mineral insufficiencies.
Recovery from eating disorders can be a long, difficult process interrupted by relapses, which occur in about half of all individuals with anorexia. Up to 20% die of complications of anorexia. The recovery rate for people with bulimia is slightly higher. Binge eaters experience many relapses and may have trouble controlling their weight even if they stop bingeing. Not enough is known about the other eating disorders to determine recovery rates. All eating disorders have serious social and emotional consequences. All except rumination disorder have serious health consequences. The sooner a person with an eating disorder gets professional help, the better the chance of recovery.
Prevention involves both preventing and relieving stressors or triggers and enlisting professional help as soon as abnormal eating patterns develop. Parents and family members may help prevent an eating disorder from developing by following the guidelines listed below:
See also Adolescent nutrition ; Alcohol consumption ; Anorexia nervosa ; Binge eating ; Body image ; Bulimia nervosa ; Calorie restriction ; Children's diets ; Diuretics and diets ; Malnutrition ; Night eating syndrome ; Nutrition and mental health ; Obesity ; Pica .
Apple, Robin, and W. Stewart Agras. Overcoming Your Eating Disorder: A Cognitive-Behavioral Therapy Approach for Bulimia Nervosa and Binge-Eating Disorder. 2nd ed. New York: Oxford University Press, 2015.
Keel, Pamela K.Eating Disorders. 2nd ed. New York: Oxford University Press, 2017.
McKnight, Lenore.Eating Disorders: A Treatment Workbook for Patients, Therapists, and Families. Pleasant Hills, CA: Benzie, 2016.
Claudat, Kimberly, and Jason M. Lavender. “An Introduction to the Special Issue on Emotion Regulation and Eating Disorders.” Eating Disorders 26, no. 1 (January–February 2018): 1–4.
Hail, Lisa, and Daniel Le Grange. “Bulemia Nervosa in Adolescents: Prevalence and Treatment Challenges.” Adolescent Health, Medicine, and Therapuetics 9 (January 2018): 11–6.
Kessler, R. C., M. Petukhova, N. A. Sampson, et al. “Lifetime Comorbidity of DSM-IV Disorders in the U.S. National Comorbidity Survey Replication Adolescent Supplement (NCS-A).” Psychological Medicine 42, no. 9 (September 1, 2012): 1997–2010.
Murphy, Rebecca, Suzanne Straebler, Zafra Cooper, et al. “Cognitive Behavioral Therapy for Eating Disorders.” Psychiatric Clinics of North America 33, no. 3 (September 2010): 611–27.
Pearson, Carolyn M., Tyler B. Mason, Li Cao, et al. “A Test of a State-Based, Self-Control Theory of Binge Eating in Adults with Obesity.” Eating Disorders 26, no. 1 (January–February 2018): 26–38.
MedlinePlus. “Eating Disorders.” U.S. National Library of Medicine, National Institutes of Health. http://www.medlineplus.gov/eatingdisorders.html (accessed April 12, 2018).
National Association of Anorexia Nervosa and Associated Disorders. “About Eating Disorders.” ANAD.org . http://www.anad.org/get-information/about-eatingdisorders (accessed April 12, 2018).
National Association of Anorexia Nervosa & Associated Disorders, 220 North Green St., Chicago, IL, 60607, (630) 577-1333, firstname.lastname@example.org, http://www.anad.org .
National Eating Disorders Association, 200 West 41st St., Ste. 1203, New York, NY, 10036, (212) 575-6200, (800) 931-2237, email@example.com, http://www.nationaleatingdisorders.org .
L. Lee Culvert