Provided by the National Institute of Mental Health
Eating is controlled by many factors, including appetite, food availability,
family, peer, and cultural practices, and attempts at voluntary control. Dieting
to a body weight leaner than needed for health is highly promoted by current
fashion trends, sales campaigns for special foods, and in some activities and
professions. Eating disorders involve serious disturbances in eating behavior,
such as extreme and unhealthy reduction of food intake or severe overeating, as
well as feelings of distress or extreme concern about body shape or weight.
Researchers are investigating how and why initially voluntary behaviors, such as
eating smaller or larger amounts of food than usual, at some point move beyond
control in some people and develop into an eating disorder. Studies on the basic
biology of appetite control and its alteration by prolonged overeating or
starvation have uncovered enormous complexity, but in the long run have the
potential to lead to new pharmacologic treatments for eating disorders.
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. The main types of eating disorders are
anorexia nervosa and bulimia nervosa.1 A third type, binge-eating disorder, has
been suggested but has not yet been approved as a formal psychiatric diagnosis.2
Eating disorders frequently develop during adolescence or early adulthood, but
some reports indicate their onset can occur during childhood or later in
adulthood.3
Eating disorders frequently co-occur with other psychiatric disorders such as
depression, substance abuse, and anxiety disorders.1 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,
therefore, is critically important.
Females are much more likely than males to develop an eating disorder. Only an
estimated 5 to 15 percent of people with anorexia or bulimia4 and an estimated
35 percent of those with binge-eating disorder5 are male.
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Anorexia Nervosa
An estimated 0.5 to 3.7 percent of females suffer from anorexia nervosa in their
lifetime.1 Symptoms of anorexia nervosa include:
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)
People with this disorder see themselves as overweight even though they are
dangerously thin. The process of eating becomes an obsession. Unusual eating
habits develop, such as avoiding food and meals, picking out a few foods and
eating these in small quantities, or carefully weighing and portioning food.
People with anorexia may repeatedly check their body weight, and many engage in
other techniques to control their weight, such as intense and compulsive
exercise, or purging by means of vomiting and abuse of laxatives, enemas, and
diuretics. Girls with anorexia often experience a delayed onset of their first
menstrual period.
The course and outcome of anorexia nervosa vary across individuals: some fully
recover after a single episode; some have a fluctuating pattern of weight gain
and relapse; and others experience a chronically deteriorating course of illness
over many years. The mortality rate among people with anorexia has been
estimated at 0.56 percent per year, or approximately 5.6 percent per decade,
which is about 12 times higher than the annual death rate due to all causes of
death among females ages 15-24 in the general population.6 The most common
causes of death are complications of the disorder, such as cardiac arrest or
electrolyte imbalance, and suicide.
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Bulimia Nervosa
An estimated 1.1 percent to 4.2 percent of females have bulimia nervosa in their
lifetime.1 Symptoms of bulimia nervosa include:
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 a week for 3 months
Self-evaluation is unduly influenced by body shape and weight
Because purging or other compensatory behavior follows the binge-eating
episodes, people with bulimia usually weigh within the normal range for their
age and height. However, like individuals with anorexia, they may fear gaining
weight, desire to lose weight, and feel intensely dissatisfied with their
bodies. People with bulimia often perform the behaviors in secrecy, feeling
disgusted and ashamed when they binge, yet relieved once they purge.
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Binge-Eating Disorder
Community surveys have estimated that between 2 percent and 5 percent of
Americans experience binge-eating disorder in a 6-month period.5,7 Symptoms of
binge-eating disorder include:
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 3 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 being embarrassed by how much one is eating; feeling disgusted with
oneself, depressed, or very guilty after overeating
Marked distress about the binge-eating behavior
The binge eating occurs, on average, at least 2 days a week for 6 months
The binge eating is not associated with the regular use of inappropriate
compensatory behaviors (e.g., purging, fasting, excessive exercise)
People with binge-eating disorder experience frequent episodes of out-of-control
eating, with the same binge-eating symptoms as those with bulimia. The main
difference is that individuals with binge-eating disorder do not purge their
bodies of excess calories. Therefore, many with the disorder 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.
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Treatment Strategies1
Eating disorders can be treated and a healthy weight 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, psychosocial interventions,
nutritional counseling and, when appropriate, medication management. At the time
of diagnosis, the clinician must determine whether the person is in immediate
danger and requires hospitalization.
Treatment of anorexia calls for a specific program that involves three main
phases: (1) restoring weight lost to severe dieting and purging; (2) treating
psychological disturbances such as distortion of body image, low self-esteem,
and interpersonal conflicts; and (3) achieving long-term remission and
rehabilitation, or full recovery. Early diagnosis and treatment increases the
treatment success rate. Use of psychotropic medication in people with anorexia
should be considered only after weight gain has been established. Certain
selective serotonin reuptake inhibitors (SSRIs) have been shown to be helpful
for weight maintenance and for resolving mood and anxiety symptoms associated
with anorexia.
The acute management of severe weight loss is usually provided in an inpatient
hospital setting, where feeding plans address the person's medical and
nutritional needs. In some cases, intravenous feeding is recommended. Once
malnutrition has been corrected and weight gain has begun, psychotherapy (often
cognitive-behavioral or interpersonal psychotherapy) can help people with
anorexia overcome low self-esteem and address distorted thought and behavior
patterns. Families are sometimes included in the therapeutic process.
The primary goal of treatment for bulimia is to reduce or eliminate binge eating
and purging behavior. To this end, nutritional rehabilitation, psychosocial
intervention, and medication management strategies are often employed.
Establishment of a pattern of regular, non-binge meals, improvement of attitudes
related to the eating disorder, encouragement of healthy but not excessive
exercise, and resolution of co-occurring conditions such as mood or anxiety
disorders are among the specific aims of these strategies. Individual
psychotherapy (especially cognitive-behavioral or interpersonal psychotherapy),
group psychotherapy that uses a cognitive-behavioral approach, and family or
marital therapy have been reported to be effective. Psychotropic medications,
primarily antidepressants such as the selective serotonin reuptake inhibitors (SSRIs),
have been found helpful for people with bulimia, particularly those with
significant symptoms of depression or anxiety, or those who have not responded
adequately to psychosocial treatment alone. These medications also may help
prevent relapse. The treatment goals and strategies for binge-eating disorder
are similar to those for bulimia, and studies are currently evaluating the
effectiveness of various interventions.
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. For some
people, treatment may be long term.
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Research Findings and Directions
Research is contributing to advances in the understanding and treatment of
eating disorders.
NIMH-funded scientists and others continue to investigate the effectiveness of
psychosocial interventions, medications, and the combination of these treatments
with the goal of improving outcomes for people with eating disorders.8,9
Research on interrupting the binge-eating cycle has shown that once a structured
pattern of eating is established, the person experiences less hunger, less
deprivation, and a reduction in negative feelings about food and eating. The two
factors that increase the likelihood of bingeing—hunger and negative
feelings—are reduced, which decreases the frequency of binges.10
Several family and twin studies are suggestive of a high heritability of
anorexia and bulimia,11,12 and researchers are searching for genes that confer
susceptibility to these disorders.13 Scientists suspect that multiple genes may
interact with environmental and other factors to increase the risk of developing
these illnesses. Identification of susceptibility genes will permit the
development of improved treatments for eating disorders.
Other studies are investigating the neurobiology of emotional and social
behavior relevant to eating disorders and the neuroscience of feeding behavior.
Scientists have learned that both appetite and energy expenditure are regulated
by a highly complex network of nerve cells and molecular messengers called
neuropeptides.14,15 These and future discoveries will provide potential targets
for the development of new pharmacologic treatments for eating disorders.
Further insight is likely to come from studying the role of gonadal
steroids.16,17 Their relevance to eating disorders is suggested by the clear
gender effect in the risk for these disorders, their emergence at puberty or
soon after, and the increased risk for eating disorders among girls with early
onset of menstruation.
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For More Information
Please visit the following link for more information about organizations that
focus on eating disorders.
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References
1American Psychiatric Association Work Group on Eating Disorders. Practice
guideline for the treatment of patients with eating disorders (revision).
American Journal of Psychiatry, 2000; 157(1 Suppl): 1-39.
2American Psychiatric Association. Diagnostic and Statistical Manual for Mental
Disorders, fourth edition (DSM-IV). Washington, DC: American Psychiatric Press,
1994.
3Becker AE, Grinspoon SK, Klibanski A, Herzog DB. Eating disorders. New England
Journal of Medicine, 1999; 340(14): 1092-8.
4Andersen AE. Eating disorders in males. In: Brownell KD, Fairburn CG, eds.
Eating disorders and obesity: a comprehensive handbook. New York: Guilford
Press, 1995; 177-87.
5Spitzer RL, Yanovski S, Wadden T, Wing R, Marcus MD, Stunkard A, Devlin M,
Mitchell J, Hasin D, Horne RL. Binge eating disorder: its further validation in
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6Sullivan PF. Mortality in anorexia nervosa. American Journal of Psychiatry,
1995; 152(7): 1073-4.
7Bruce B, Agras WS. Binge eating in females: a population-based investigation.
International Journal of Eating Disorders, 1992; 12: 365-73.
8Agras WS. Pharmacotherapy of bulimia nervosa and binge eating disorder:
longer-term outcomes. Psychopharmacology Bulletin, 1997; 33(3): 433-6.
9Wilfley DE, Cohen LR. Psychological treatment of bulimia nervosa and binge
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10Apple RF, Agras WS. Overcoming eating disorders. A cognitive-behavioral
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Company, 1997.
11Strober M, Freeman R, Lampert C, Diamond J, Kaye W. Controlled family study of
anorexia nervosa and bulimia nervosa: evidence of shared liability and
transmission of partial syndromes. American Journal of Psychiatry, 2000; 157(3):
393-401.
12Walters EE, Kendler KS. Anorexia nervosa and anorexic-like syndromes in a
population-based female twin sample. American Journal of Psychiatry, 1995;
152(1): 64-71.
13Kaye WH, Lilenfeld LR, Berrettini WH, Strober M, Devlin B, Klump KL, Goldman
D, Bulik CM, Halmi KA, Fichter MM, Kaplan A, Woodside DB, Treasure J, Plotnicov
KH, Pollice C, Rao R, McConaha CW. A search for susceptibility loci for anorexia
nervosa: methods and sample description. Biological Psychiatry, 2000; 47(9):
794-803.
14Frank GK, Kaye WH, Altemus M, Greeno CG. CSF oxytocin and vasopressin levels
after recovery from bulimia nervosa and anorexia nervosa, bulimic subtype.
Biological Psychiatry, 2000; 48(4): 315-8.
15Elias CF, Kelly JF, Lee CE, Ahima RS, Drucker DJ, Saper CB, Elmquist JK.
Chemical characterization of leptin-activated neurons in the rat brain. Journal
of Comparative Neurology, 2000; 423(2): 261-81.
16Devlin MJ, Walsh BT, Katz JL, Roose SP, Linkei DM, Wright L, Vande Wiele R,
Glassman AH. Hypothalamic-pituitary-gonadal function in anorexia nervosa and
bulimia. Psychiatry Research, 1989; 28(1): 11-24.
17Flanagan-Cato LM, King JF, Blechman JG, O'Brien MP. Estrogen reduces
cholecystokinin-induced c-Fos expression in the rat brain. Neuroendocrinology,
1998; 67(6): 384-91.
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This publication was written by Melissa Spearing, Office of Communications and
Public Liaison, National Institute of Mental Health (NIMH). Expert assistance
was provided by NIMH Director Steven E. Hyman, M.D., and NIMH staff members
Bruce N. Cuthbert, Ph.D., Regina Dolan-Sewell, Ph.D., Benedetto Vitiello, Ph.D.,
Clarissa K. Wittenberg, and Constance Burr. Editorial assistance was provided by
Margaret Strock and Lisa D. Alberts, also NIMH staff members.
All material in this publication is in the public domain and may be copied or
reproduced without permission of the Institute. Citation of the source is
appreciated.
NIH Publication No. 01-4901
Printed 2001
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