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.
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.
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.
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.
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.
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.
For More Information
National Institute of Mental Health
(NIMH)
Office of Communications and Public
Liaison
Public Inquiries: (301) 443-4513
Media Inquiries: (301) 443-4536
E-mail: nimhinfo@ni
h.gov
Web site: http://www.nimh.nih.gov
Harvard Eating Disorders Center
c/o Massachusetts General Hospital
15 Parkman Street
Boston, MA 02114
Phone: (617) 726-8470
Web site: ht
tp://www.hedc.org
National Association of Anorexia Nervosa
and Associated Disorders
P.O. Box 7
Highland Park, IL 60035
Phone: (847) 831-3438
Web site: ht
tp://www.anad.org
National Eating Disorders Association
603 Stewart Street, Suite 803
Seattle, WA 98101
Phone: (206) 382-3587
Web site: http://www.nationaleating
disorders.org
