10. Feeding and Eating Disorders
10.1. Pica
10.2. Rumination Disorder
10.3. Avoidant/Restrictive Food Intake Disorder
10.4. Anorexia Nervosa
10.5. Bulimia Nervosa
10.6. Binge-Eating Disorder
Feading and Eating disorders are characterized by a persistent disturbance of eating
or eating-related behavior that results in the altered consumption or absorption of
food and that significantly impairs physical health or psychosocial functioning. Diagnostic
criteria are provided for pica, rumination disorder, avoidant/restrictive food intake
disorder, anorexia nervosa, bulimia nervosa, and binge-eating disorder.
The diagnostic criteria for rumination disorder, avoidant/restrictive food intake disorder,
anorexia nervosa, bulimia nervosa, and binge-eating disorder result in a classification
scheme that is mutually exclusive, so that during a single episode, only one of these
diagnoses can be assigned. The rationale for this approach is that, despite a number of
common psychological and behavioral features, the disorders differ substantially in clinical
course, outcome, and treatment needs. A diagnosis of pica, however, may be assigned
in the presence of any other feeding and eating disorder.
Some individuals with disorders described in this chapter report eating-related symptoms
resembling those typically endorsed by individuals with substance use disorders,
such as craving and patterns of compulsive use. This resemblance may reflect the involvement
of the same neural systems, including those implicated in regulatory self-control and
reward, in both groups of disorders. However, the relative contributions of shared and
distinct factors in the development and perpetuation of eating and substance use disorders
remain insufficiently understood.
Finally, obesity is not included in DSM-5 as a mental disorder. Obesity (excess body fat)
results from the long-term excess of energy intake relative to energy expenditure. A range
of genetic, physiological, behavioral, and environmental factors that vary across individuals
contributes to the development of obesity; thus, obesity is not considered a mental
disorder. However, there are robust associations between obesity and a number of mental
disorders (e.g., binge-eating disorder, depressive and bipolar disorders, schizophrenia).
The side effects of some psychotropic medications contribute importantly to the development
of obesity, and obesity may be a risk factor for the development of some mental disorders
(e.g., depressive disorders).
The essential feature of pica is the eating of one or more nonnutritive, nonfood substances on a persistent basis over a period of at least 1 month (Criterion A) that is severe enough to warrant clinical attention. Typical substances ingested tend to vary with age and availability and might include paper, soap, cloth, hair, string, wool, soil, chalk, talcum powder, paint, gum, metal, pebbles, charcoal or coal, ash, clay, starch, or ice. The term nonfood is included because the diagnosis of pica does not apply to ingestion of diet products that have minimal nutritional content. There is typically no aversion to food in general. The eating of nonnutritive, nonfood substances must be developmentally inappropriate (Criterion B) and not part of a culturally supported or socially normative practice (Criterion C). A minimum age of 2 years is suggested for a pica diagnosis to exclude developmentally normal mouthing of objects by infants that results in ingestion. The eating of nonnutritive, nonfood substances can be an associated feature of other mental disorders (e.g., intellectual disability [intellectual developmental disorder], autism spectrum disorder, schizophrenia). If the eating behavior occurs exclusively in the context of another mental disorder, a separate diagnosis of pica should be made only if the eating behavior is sufficientiy severe to warrant additional clinical attention (Criterion D).
Although deficiencies in vitamins or minerals (e.g., zinc, iron) have been reported in some instances, often no specific biological abnormalities are found. In some cases, pica comes to clinical attention only following general medical complications (e.g., mechanical bowel problems; intestinal obstruction, such as that resulting from a bezoar; intestinal perforation; infections such as toxoplasmosis and toxocariasis as a result of ingesting feces or dirt; poisoning, such as by ingestion of lead-based paint).
The prevalence of pica is unclear. Among individuals with intellectual disability, the prevalence of pica appears to increase with the severity of the condition,
In some populations, the eating of earth or other seemingly nonnutritive substances is believed to be of spiritual, medicinal, or other social value, or may be a culturally supported or socially normative practice. Such behavior does not warrant a diagnosis of pica (Criterion C).
Pica occurs in both males and females. It can occur in females during pregnancy; however, little is known about the course of pica in the postpartum period.
Pica can significantly impair physical functioning, but it is rarely the sole cause of impairment
in social functioning. Pica often occurs with other disorders associated with impaired
social functioning.
The essential feature of rumination disorder is the repeated regurgitation of food occurring after feeding or eating over a period of at least 1 month (Criterion A). Previously swallowed food that may be partially digested is brought up into the mouth without apparent nausea, involuntary retching, or disgust. The food may be re-chewed and then ejected from the mouth or re-swallowed. Regurgitation in rumination disorder should be frequent, occurring at least several times per week, typically daily. The behavior is not better explained by an associated gastrointestinal or other medical condition (e.g., gastroesophageal reflux, pyloric stenosis) (Criterion B) and does not occur exclusively during the course of anorexia nervosa, bulimia nervosa, binge-eating disorder, or avoidant/restrictive food intake disorder (Criterion C). If the symptoms occur in the context of another mental disorder (e.g., intellectual disability [intellectual developmental disorder], neurodevelopmental disorder), they must be sufficiently severe to warrant additional clinical attention (Criterion D) and should represent a primary aspect of the individual's presentation requiring intervention. The disorder may be diagnosed across the life span, particularly in individuals who also have intellectual disability. Many individuals with rumination disorder can be directly observed engaging in the behavior by the clinician. In other instances diagnosis can be made on the basis of self-report or corroborative information from parents or caregivers. Individuals may describe the behavior as habitual or outside of their control.
Infants with rumination disorder display a characteristic position of straining and arching the back with the head held back, making sucking movements with their tongue. They may give the impression of gaining satisfaction from the activity. They may be irritable and hungry between episodes of regurgitation. Weight loss and failure to make expected weight gains are common features in infants with rumination disorder. Malnutrition may occur despite the infant's apparent hunger and the ingestion of relatively large amounts of food, particularly in severe cases, when regurgitation immediately follows each feeding episode and regurgitated food is expelled. Malnutrition might also occur in older children and adults, particularly when the regurgitation is accompanied by restriction of intake. Adolescents and adults may attempt to disguise the regurgitation behavior by placing a hand over the mouth or coughing. Some will avoid eating with others because of the acknowledged soqal undesirability of the behavior. This may extend to an avoidance of eating prior to social situations, such as work or school (e.g., avoiding breakfast because it may be followed by regurgitation).
Prevalence data for rumination disorder are inconclusive, but the disorder is commonly reported to be higher in certain groups, such as individuals with intellectual disability.
Malnutrition secondary to repeated regurgitation may be associated with growth delay
and have a negative effect on development and learning potential. Some older individuals
with rumination disorder deliberately restrict their food intake because of the social undesirability
of regurgitation. They may therefore present with weight loss or low weight.
In older children, adolescents, and adults, social functioning is more likely to be adversely
affected.
Avoidant/restrictive food intake disorder replaces and extends the DSM-IV diagnosis of
feeding disorder of infancy or early childhood. The main diagnostic feature of avoidant/
restrictive food intake disorder is avoidance or restriction of food intake (Criterion A)
manifested by clinically significant failure to meet requirements for nutrition or insufficient
energy intake through oral intake of food. One or more of the following key features
must be present: significant weight loss, significant nutritional deficiency (or related
health impact), dependence on enteral feeding or oral nutritional supplements, or marked
interference with psychosocial functioning. The determination of whether weight loss is
significant (Criterion Al) is a clinical judgment; instead of losing weight, children and adolescents
who have not completed growth may not maintain weight or height increases
along their developmental trajectory.
Determination of significant nutritional deficiency (Criterion A2) is also based on clinical
assessment (e.g., assessment of dietary intake, physical examination, and laboratory
testing), and related impact on physical health can be of a similar severity to that seen in
anorexia nervosa (e.g., hypothermia, bradycardia, anemia). In severe cases, particularly in
infants, malnutrition can be life threatening. "Dependence" on enteral feeding or oral nutritional
supplements (Criterion A3) means that supplementary feeding is required to sustain
adequate intake. Examples of individuals requiring supplementary feeding include
infants with failure to thrive who require nasogastric tube feeding, children with neurodevelopmental
disorders who are dependent on nutritionally complete supplements, and
individuals who rely on gastrostomy tube feeding or complete oral nutrition supplements
in the absence of an underlying medical condition. Inability to participate in normal social
activities, such as eating with others, or to sustain relationships as a result of the disturbance
would inculcate marked interference with psychosocial functioning (Criterion A4).
Avoidant/restrictive food intake disorder does not include avoidance or restriction of
food intake related to lack of availability of food or to cultural practices (e.g., religious fasting
or normal dieting) (Criterion B), nor does it include developmentally normal behaviors
(e.g., picky eating in toddlers, reduced intake in older adults). The disturbance is not better
explained by excessive concern about body weight or shape (Criterion C) or by concurrent
medical factors or mental disorders (Criterion D).
In some individuals, food avoidance or restriction may be based on the sensory characteristics
of qualities of food, such as extreme sensitivity to appearance, color, smell,
texture, temperature, or taste. Such behavior has been described as "restrictive eating,"
"selective eating," "choosy eating," "perseverant eating," "chronic food refusal," and
"food neophobia" and may manifest as refusal to eat particular brands of foods or to tolerate
the smell of food being eaten by others. Individuals with heightened sensory sensitivities
associated with autism may show similar behaviors.
Food avoidance or restriction may also represent a conditioned negative response associated
with food intake following, or in anticipation of, an aversive experience, such as
choking; a traumatic investigation, usually involving the gastrointestinal tract (e.g., esophagoscopy);
or repeated vomiting. The terms frinctional dysphagia and globus hystericus have
also been used for such conditions.
Several features may be associated with food avoidance or reduced food intake, including a lack of interest in eating or food, leading to weight loss or faltering growth. Very young infants may present as being too sleepy, distressed, or agitated to feed. Infants and young children may not engage with the primary caregiver during feeding or communicate hunger in favor of other activities. In older children and adolescents, food avoidance or restriction may be associated with more generalized emotional difficulties that do not meet diagnostic criteria for an anxiety, depressive, or bipolar disorder, sometimes called "food avoidance emotional disorder."
Presentations similar to avoidant/restrictive food intake disorder occur in various populations, including in the United States, Canada, Australia, and Europe. Avoidant/restrictive food intake disorder should not be diagnosed when avoidance of food intake is solely related to specific religious or cultural practices.
Avoidant/restrictive food intake disorder is equally common in males and females in infancy and early childhood, but avoidant/restrictive food intake disorder comorbid with autism spectrum disorder has a male predominance. Food avoidance or restriction related to altered sensory sensitivities can occur in some physiological conditions, most notably pregnancy, but is not usually extreme and does not meet full criteria for the disorder.
Associated developmental and functional limitations include impairment of physical development
and social difficulties that can have a significant negative impact on family
function.
There are three essential features of anorexia nervosa: persistent energy intake restriction;
intense fear of gaining weight or of becoming fat, or persistent behavior that interferes
with weight gain; and a disturbance in self-perceived weight or shape. The individual maintains
a body weight that is below a minimally normal level for age, sex, developmental trajectory,
and physical health (Criterion A). Individuals' body weights frequently meet this
criterion following a significant weight loss, but among children and adolescents, there
may alternatively be failure to make expected weight gain or to maintain a normal developmental
trajectory (i.e., while growing in height) instead of weight loss.
Criterion A requires that the individual's weight be significantly low (i.e., less than
minimally normal or, for children and adolescents, less than that minimally expected).
Weight assessment can be challenging because normal weight range differs among individuals,
and different thresholds have been published defining thinness or underweight
status. Body mass index (BMI; calculated as weight in kilograms/height in meters^) is a
useful measure to assess body weight for height. For adults, a BMI of 18.5 kg/m^ has been
employed by the Centers for Disease Control and Prevention (CDC) and the World Health
Organization (WHO) as the lower limit of normal body weight. Therefore, most adults with
a BMI greater than or equal to 18.5 kg/m^ would not be considered to have a significantly
low body weight. On the other hand, a BMI of lower than 17.0 kg/m^ has been considered
by the WHO to indicate moderate or severe thinness; therefore, an individual with a BMI
less than 17.0 kg/m^ would likely be considered to have a significantly low weight. An
adult with a BMI between 17.0 and 18.5 kg/m^, or even above 18.5 kg/m , might be considered
to have a significantly low weight if clinical history or other physiological information
supports this judgment.
For children and adolescents, determining a BMI-for-age percentile is useful (see, e.g.,
the CDC BMI percentile calculator for children and teenagers. As for adults, it is not possible
to provide definitive standards forjudging whether a child's or an adolescent's weight
is significantly low, and variations in developmental trajectories among youth limit the
utility of simple numerical guidelines. The CDC has used a BMI-for-age below the 5th percentile
as suggesting underweight; however, children and adolescents with a BMI above
this benchmark may be judged to be significantly underweight in light of failure to maintain
their expected growth trajectory. In summary, in determining whether Criterion A is
met, the clinician should consider available numerical guidelines, as well as the individual's
body build, weight history, and any physiological disturbances.
Individuals with this disorder typically display an intense fear of gaining weight or of
becoming fat (Criterion B). This intense fear of becoming fat is usually not alleviated by
weight loss. In fact, concern about weight gain may increase even as weight falls. Younger
individuals with anorexia nervosa, as well as some adults, may not recognize or acknowledge
a fear of weight gain. In the absence of another explanation for the significantly low
weight, clinician inference drawn from collateral history, observational data, physical and
laboratory findings, or longitudinal course either indicating a fear of weight gain or supporting
persistent behaviors that prevent it may be used to establish Criterion B.
The experience and significance of body weight and shape are distorted in these individuals
(Criterion C). Some individuals feel globally overweight. Others realize that they
are thin but are still concerned that certain body parts, particularly the abdomen, buttocks,
and thighs, are "too fat." They may employ a variety of techniques to evaluate their body
size or weight, including frequent weighing, obsessive measuring of body parts, and persistent
use of a mirror to check for perceived areas of "fat." The self-esteem of individuals
with anorexia nervosa is highly dependent on their perceptions of body shape and weight.
Weight loss is often viewed as an impressive achievement and a sign of extraordinary selfdiscipline,
whereas weight gain is perceived as an unacceptable failure of self-control. Although
some individuals with this disorder may acknowledge being thin, they often do
not recognize the serious medical implications of their malnourished state.
Often, the individual is brought to professional attention by family members after marked
weight loss (or failure to make expected weight gains) has occurred. If individuals seek help
on their own, it is usually because of distress over the somatic and psychological sequelae
of starvation. It is rare for an individual with anorexia nervosa to complain of weight loss
per se. In fact, individuals with anorexia nervosa frequently either lack insight into or deny
the problem. It is therefore often important to obtain information from family members or
other sources to evaluate the history of weight loss and other features of the illness.
The semi-starvation of anorexia nervosa, and the purging behaviors sometimes associated
with it, can result in significant and potentially life-threatening medical conditions. The
nutritional compromise associated with this disorder affects most major organ systems
and can produce a variety of disturbances. Physiological disturbances, including amenorrhea
and vital sign abnormalities, are common. While most of the physiological disturbances
associated with malnutrition are reversible with nutritional rehabilitation, some,
including loss of bone mineral density, are often not completely reversible. Behaviors such
as self-induced vomiting and misuse of laxatives, diuretics, and enemas may cause a number
of disturbances that lead to abnormal laboratory findings; however, some individuals
with anorexia nervosa exhibit no laboratory abnormalities.
When seriously underweight, many individuals with anorexia nervosa have depressive
signs and symptoms such as depressed mood, social withdrawal, irritability, insomnia, and
diminished interest in sex. Because these features are also observed in individuals without
anorexia nervosa who are significantly undernourished, many of the depressive features
may be secondary to the physiological sequelae of semi-starvation, although they may also
be sufficiently severe to warrant an additional diagnosis of major depressive disorder.
Obsessive-compulsive features, both related and unrelated to food, are often prominent.
Most individuals with anorexia nervosa are preoccupied with thoughts of food. Some collect
recipes or hoard food. Observations of behaviors associated with other forms of starvation
suggest that obsessions and compulsions related to food may be exacerbated by
imdemutrition. When individuals with anorexia nervosa exhibit obsessions and compulsions
that are not related to food, body shape, or weight, an additional diagnosis of obsessive-
compulsive disorder (OCD) may be warranted.
Other features sometimes associated with anorexia nervosa include concerns about
eating in public, feelings of ineffectiveness, a strong desire to control one's environment,
inflexible thinking, limited social spontaneity, and overly restrained emotional expression.
Compared with individuals with anorexia nervosa, restricting type, those with
binge-eating/purging type have higher rates of impulsivity and are more likely to abuse
alcohol and other drugs.
A subgroup of individuals with anorexia nervosa show excessive levels of physical activity.
Increases in physical activity often precede onset of the disorder, and over the
course of the disorder increased activity accelerates weight loss. During treatment, excessive
activity may be difficult to control, thereby jeopardizing weight recovery.
Individuals with anorexia nervosa may misuse medications, such as by manipulating
dosage, in order to achieve weight loss or avoid weight gain. Individuals with diabetes
mellitus may omit or reduce insulin doses in order to minimize carbohydrate metabolism.
The 12-month prevalence of anorexia nervosa among young females is approximately 0.4%. Less is known about prevalence among males, but anorexia nervosa is far less common in males than in females, with clinical populations generally reflecting approximately a 10:1 female-to-male ratio.
Anorexia nervosa occurs across culturally and socially diverse populations, although available evidence suggests cross-cultural variation in its occurrence and presentation. Anorexia nervosa is probably most prevalent in post-industrialized, high-income countries such as in the United States, many European countries, Australia, New Zealand, and Japan, but its incidence in most low- and middle-income countries is uncertain. Whereas the prevalence of anorexia nervosa appears comparatively low among Latinos, African Americans, and Asians in the United States, clinicians should be aware that mental health service utilization among individuals with an eating disorder is significantly lower in these ethnic groups and that the low rates may reflect an ascertainment bias. The presentation of weight concerns among individuals with eating and feeding disorders varies substantially across cultural contexts. The absence of an expressed intense fear of weight gain, sometimes referred to as "fat phobia," appears to be relatively more common in populations in Asia, where the rationale for dietary restriction is commonly related to a more culturally sanctioned complaint such as gastrointestinal discomfort. Within the United States, presentations without a stated intense fear of weight gain may be comparatively more common among Latino groups.
Suicide risk is elevated in anorexia nervosa, with rates reported as 12 per 100,000 per year. Comprehensive evaluation of individuals with anorexia nervosa should include assessment of suicide-related ideation and behaviors as well as other risk factors for suicide, including a history of suicide attempt(s).
Individuals with anorexia nervosa may exhibit a range of functional limitations associated
with the disorder. While some individuals remain active in social and professional functioning,
others demonstrate significant social isolation and/or failure to fulfill academic or
career potential.
There are three essential features of bulimia nervosa: recurrent episodes of binge eating
(Criterion A), recurrent inappropriate compensatory behaviors to prevent weight gain
(Criterion B), and self-evaluation that is unduly influenced by body shape and weight
(Criterion D). To qualify for the diagnosis, the binge eating and inappropriate compensatory
behaviors must occur, on average, at least once per week for 3 months (Criterion C).
An "episode of binge eating" is defined as eating, in a discrete period of time, an
amount of food that is definitely larger than most individuals would eat in a similar period
of time under similar circumstances (Criterion Al). The context in which the eating occurs
may affect the clinician's estimation of whether the intake is excessive. For example, a
quantity of food that might be regarded as excessive for a typical meal might be considered
normal during a celebration or holiday meal. A "discrete period of time" refers to a
limited period, usually less than 2 hours. A single episode of binge eating need not be restricted
to one setting. For example, an individual may begin a binge in a restaurant and
then continue to eat on returning home. Continual snacking on small amounts of food
throughout the day would not be considered an eating binge.
An occurrence of excessive food consumption must be accompanied by a sense of lack
of control (Criterion A2) to be considered an episode of binge eating. An indicator of loss
of control is the inability to refrain from eating or to stop eating once started. Some individuals
describe a dissociative quality during, or following, the binge-eating episodes. The
impairment in control associated with binge eating may not be absolute; for example, an
individual may continue binge eating while the telephone is ringing but will cease if a
roommate or spouse unexpectedly enters the room. Some individuals report that their
binge-eating episodes are no longer characterized by an acute feeling of loss of control but
rather by a more generalized pattern of uncontrolled eating. If individuals report that they
have abandoned efforts to control their eating, loss of control should be considered as
present. Binge eating can also be planned in some instances.
The type of food consumed during binges varies both across individuals and for a
given individual. Binge eating appears to be characterized more by an abnormality in the
amount of food consumed than by a craving for a specific nutrient. However, during binges,
individuals tend to eat foods they would otherwise avoid.
Individuals with bulimia nervosa are typically ashamed of their eating problems and
attempt to conceal their symptoms. Binge eating usually occurs in secrecy or as inconspicuously
as possible. The binge eating often continues until the individual is uncomfortably,
or even painfully, full. The most common antecedent of binge eating is negative affect.
Other triggers include interpersonal stressors; dietary restraint; negative feelings related
to body weight, body shape, and food; and boredom. Binge eating may minimize or mitigate
factors that precipitated the episode in the short-term, but negative self-evaluation
and dysphoria often are the delayed consequences.
Another essential feature of bulimia nervosa is the recurrent use of inappropriate compensatory
behaviors to prevent weight gain, collectively referred to as purge behaviors or
purging (Criterion B). Many individuals with bulimia nervosa employ several methods to
compensate for binge eating. Vomiting is the most common inappropriate compensatory
behavior. The immediate effects of vomiting include relief from physical discomfort and reduction
of fear of gaining weight. In some cases, vomiting becomes a goal in itself, and the
individual will binge eat in order to vomit or will vomit after eating a small amount of food.
Individuals with bulimia nervosa may use a variety of methods to induce vomiting, including
the use of fingers or instruments to stimulate the gag reflex. Individuals generally
become adept at inducing vomiting and are eventually able to vomit at will. Rarely, individuals
consume syrup of ipecac to induce vomiting. Other purging behaviors include the
misuse of laxatives and diuretics. A number of other compensatory methods may also be
used in rare cases. Individuals with bulimia nervosa may misuse enemas following episodes
of binge eating, but this is seldom the sole compensatory method employed. Individuals
with this disorder may take thyroid hormone in an attempt to avoid weight gain.
Individuals with diabetes mellitus and bulimia nervosa may omit or reduce insulin doses in
order to reduce the metabolism of food consumed during eating binges. Individuals with
bulimia nervosa may fast for a day or more or exercise excessively in an attempt to prevent
weight gain. Exercise may be considered excessive when it significantly interferes with important
activities, when it occurs at inappropriate times or in inappropriate settings, or
when the individual continues to exercise despite injury or other medical complications.
Individuals with bulimia nervosa place an excessive emphasis on body shape or weight
in their self-evaluation, and these factors are typically extremely important in determining
self-esteem (Criterion D). Individuals with this disorder may closely resemble those w^ith
anorexia nervosa in their fear of gaining weight, in their desire to lose weight, and in the
level of dissatisfaction with their bodies. However, a diagnosis of bulimia nervosa should
not be given when the disturbance occurs only during episodes of anorexia nervosa (Criterion
E).
Individuals with bulimia nervosa typically are within the normal weight or overweight
range (body mass index [BMI] > 18.5 and < 30 in adults). The disorder occurs but is uncommon
among obese individuals. Between eating binges, individuals with bulimia nervosa
typically restrict their total caloric consumption and preferentially select low-calorie
("diet") foods while avoiding foods that they perceive to be fattening or likely to trigger a
binge.
Menstrual irregularity or amenorrhea often occurs among females with bulimia nervosa;
it is uncertain whether such disturbances are related to weight fluctuations, to nutritional
deficiencies, or to emotional distress. The fluid and electrolyte disturbances
resulting from the purging behavior are sometimes sufficiently severe to constitute medically
serious problems. Rare but potentially fatal complications include esophageal tears,
gastric rupture, and cardiac arrhythmias. Serious cardiac and skeletal myopathies have
been reported among individuals following repeated use of syrup of ipecac to induce vomiting.
Individuals who chronically abuse laxatives may become dependent on their use to
stimulate bowel movements. Gastrointestinal symptoms are commonly associated with
bulimia nervosa, and rectal prolapse has also been reported among individuals with this
disorder.
Twelve-month prevalence of bulimia nervosa among young females is 1%-1.5%. Point prevalence is highest among young adults since the disorder peaks in older adolescence and young adulthood. Less is known about the point prevalence of bulimia nervosa in males, but bulimia nervosa is far less common in males than it is in females, with an approximately 10:1 female-to-male ratio.
Bulimia nervosa has been reported to occur with roughly similar frequencies in most industrialized countries, including the United States, Canada, many European countries, Australia, Japan, New Zealand, and South Africa. In clinical studies of bulimia nervosa in the United States, individuals presenting with this disorder are primarily white. However, the disorder also occurs in other ethnic groups and with prevalence comparable to estimated prevalences observed in white samples.
Bulimia nervosa is far more common in females than in males. Males are especially underrepresented in treatment-seeking samples, for reasons that have not yet been systematically examined.
Suicide risk is elevated in bulimia nervosa. Comprehensive evaluation of individuals with this disorder should include assessment of suicide-related ideation and behaviors as well as other risk factors for suicide, including a history of suicide attempts.
Individuals with bulimia nervosa may exhibit a range of functional limitations associated
with the disorder. A minority of individuals report severe role impairment, with the social-
life domain most likely to be adversely affected by bulimia nervosa.
The essential feature of binge-eating disorder is recurrent episodes binge eating that must
occur, on average, at least once per week for 3 months (Criterion D). An "episode of binge
eating" is defined as eating, in a discrete period of time, an amount of food that is definitely
larger than most people would eat in a similar period of time under similar circumstances
(Criterion Al). The context in which the eating occurs may affect the clinician's
estimation of whether the intake is excessive. For example, a quantity of food that might be
regarded as excessive for a typical meal might be considered normal during a celebration
or holiday meal. A ''discrete period of time" refers to a limited period, usually less than
2 hours. A single episode of binge eating need not be restricted to one setting. For example,
an individual may begin a binge in a restaurant and then continue to eat on returning
home. Continual snacking on small amounts of food throughout the day would not be considered
an eating binge.
An occurrence of excessive food consumption must be accompanied by a sense of lack
of control (Criterion A2) to be considered an episode of binge eating. An indicator of loss
of control is the inability to refrain from eating or to stop eating once started. Some individuals
describe a dissociative quality during, or following, the binge-eating episodes. The
impairment in control associated with binge eating may not be absolute; for example, an
individual may continue binge eating while the telephone is ringing but will cease if a
roommate or spouse unexpectedly enters the room. Some individuals report that their
binge-eating episodes are no longer characterized by an acute feeling of loss of control but
rather by a more generalized pattern of uncontrolled eating. If individuals report that they
have abandoned efforts to control their eating, loss of control may still be considered as
present. Binge eating can also be planned in some instances.
The type of food consumed during binges varies both across individuals and for a given
individual. Binge eating appears to be characterized more by an abnormality in the amount
of food consumed than by a craving for a specific nutrient.
Binge eating must be characterized by marked distress (Criterion C) and at least three
of the following features: eating much more rapidly than normal; eating until feeling uncomfortably
full; eating large amoimts of food when not feeling physically hungry; eating
alone because of feeling embarrassed by how much one is eating; and feeling disgusted
with oneself, depressed, or very guilty afterward (Criterion B).
Individuals with binge-eating disorder are typically ashamed of their eating problems
and attempt to conceal their symptoms. Binge eating usually occurs in secrecy or as inconspicuously
as possible. The most common antecedent of binge eating is negative affect.
Other triggers include inteφersonal stressors; dietary restraint; negative feelings related
to body weight, body shape, and food; and boredom. Binge eating may miriimize or mitigate
factors that precipitated the episode in the short-term, but negative self-evaluation
and dysphoria often are the delayed consequences.
Binge-eating disorder occurs in normal-weight/overweight and obese individuals. It is reliably associated with overweight and obesity in treatment-seeking individuals. Nevertheless, binge-eating disorder is distinct from obesity. Most obese individuals do not engage in recurrent binge eating. In addition, compared with weight-matched obese individuals without binge-eating disorder, those with the disorder consume more calories in laboratory studies of eating behavior and have greater functional impairment, lower quality of life, more subjective distress, and greater psychiatric comorbidity.
Twelve-month prevalence of binge-eating disorder among U.S. adult (age 18 or older) females and males is 1.6% and 0.8%, respectively. The gender ratio is far less skewed in bingeeating disorder than in bulimia nervosa. Binge-eating disorder is as prevalent among females from racial or ethnic minority groups as has been reported for white females. The disorder is more prevalent among individuals seeking weight-loss treatment than in the general population.
Genetic and physiological. Binge-eating disorder appears to run in families, which may reflect additive genetic influences.
Binge-eating disorder occurs with roughly similar frequencies in most industrialized countries, including the United States, Canada, many European countries, Australia, and New Zealand. In the United States, the prevalence of binge-eating disorder appears comparable among non-Latino whites. Latinos, Asians, and African Americans.
Binge-eating disorder is associated with a range of functional consequences, including social role adjustment problems, impaired health-related quality of life and life satisfaction, increased medical morbidity and mortality, and associated increased health care utilization compared with body mass index (BMI)-matched control subjects. It may also be associated with an increased risk for weight gain and the development of obesity.