Anorexia, Bulimia (Encyclopedia of Food & Culture)
ANOREXIA, BULIMIA. Anorexia nervosa (AN), bulimia nervosa (BN), and Eating Disorder Not Otherwise Specified (EDNOS) are three of a spectrum of conditions, commonly known as eating disorders, associated with abnormal eating patterns and a desire to be thin. The abnormal eating patterns in these eating disorders include restriction of food intake, binge eating, and purging with laxatives or by self-induced vomiting. Persons with each of these disorders may go through periods of restriction, binge eating with purging, and binge eating without purging.
The term "eating disorders" for these conditions is both correct and misleading. These disorders center around issues of eating, or, to be more exact, food consumption, and certainly can be qualified as disorders, but more than eating is disordered in these conditions: they are associated with a complex of psychological, physiological, neurological, and hormonal changes, which may be due to the disease itself, or to the changes in weight associated with inappropriate food intakes and energy outputs, or both together.
The notion that thinness is desirable, particularly in women, and that one can never be "too rich or too thin," now permeates Western societies and is becoming increasingly common elsewhere. Teenagers, who are normally preoccupied with body image, and prone to be concerned about gaining weight, may incorrectly perceive themselves as being overweight, because puberty coincides with marked changes in body shape and, for girls, increased body fat content with fat deposition in the hips. Surveys in Western countries have shown that at any one time, up to two-thirds of female high school students either are on a weight loss diet or were on one in the recent past. In the United States, eating disorders seem to be less common among African-American and Asian females than among white females, equally common among Latina females, and surprisingly common among Native Americans. Japan seems to be the country with the highest prevalence of eating disorders. Other countries seem to be catching up, wherever there is access to food and to Western modes of behavior, as exemplified in the media.
Psychological conditions associated with eating disorders include depression, affecting 505 percent of people with eating problems; bipolar disorder (manic-depressive illness, 45 percent); obsessive-compulsive disorder, affecting as many as 25 percent of people with AN, fewer in those with BN; substance abuse, in up to one-third of patients with BN; and personality disorders, particularly avoidant, in other words, mistrusting, personality. Twenty to fifty percent of patients with BN (and to a lesser extent patients with AN and other eating disorders) have experienced sexual abuse.
A syndrome called "the female athlete triad"onsisting of disordered eating, amenorrhea (disruption of menses), and osteoporosiss becoming more common as athletic prowess has become desirable for women and as women have better access to athletic facilities in the United States because of Title IX of the Educational Assistance Act (1974). Patients with Type I diabetes mellitus appear to be more prone than the general population to eating disorders, and may use underdosing with insulin to lose weighthen they do not take enough insulin, the body fails to use and store the calories they eat and relies on breakdown of fat and muscle for fuel.
Patients with eating disorders may become parents, may have difficulties nurturing their own children, and may transmit disordered attitudes toward eating to their children. The health care team should take these difficulties into account in treatment plans for both parent and child.
Anorexia nervosa (AN) represents an extreme version of the desire for thinness. The term "anorexia" is a misnomer, for a person with this condition does have an appetite, but restricts food intake and denies the desire to eat with the apparent aim of having precise control over body shape and weight. Perhaps the German Pubertätmagersuchtseeking thinness at puberty"s a more accurate term, although the disorder has antecedents in childhood and continues into adulthood.
Epidemiology. In the United States, nearly 90 percent of patients with overt, clinically recognized AN are females between the ages of twelve and twenty-three, although younger and older patients as well as males may also develop the disease. The prevalence of AN appeared to rise during the twentieth century, with a lifetime risk among women of 0.5 percent to 3.7 percent and a male to female prevalence ratio between 1 to 6 and 1 to 10. The prevalence among young adolescent males is higher, perhaps reflecting a secular trend or an increasing emphasis on male appearance and "fitness."
The only groups among whom the disease has been recognized are groups who have easy access to food, and among whom being thin is a socially desirable state. However, conditions clinically indistinguishable from AN have existed in Western cultures prior to the twentieth century, particularly during the late Middle Ages and Renaissance, when they were associated with religious asceticismhe professed goal was to demonstrate the person's ability to deny the needs and pleasures of the flesh, rather than to be thin for social acceptance. Similar conditions associated with religious practices also occur in other cultures.
Etiology. Scientific opinion concerning the etiology of AN has vacillated between a biological and genetic explanation and a sociopsychological one. The patient's complaints lie in the psychological realm, while the disease presents features that point to biological and genetic components. There is a significantly higher concordance of anorexia nervosa among monozygotic twins (identical, that is, having the same genes) than among dizygotic twins (fraternal, that is, genetically only as close as a non-twin sibling). Family members have a higher than expected prevalence of other affective (emotional) and addictive disorders.
A host of neurohormonal changes appear once starvation has set in, but it is unclear which of these changes are causal, which are due to progression of the disease, and which are due to semistarvation. A reasonable explanation for the condition is that the person first restrains eating or performs excessive exercise for psychosocial reasons, and then develops a biologically driven self-perpetuating condition.
Development, signs, symptoms and biological findings. Anorexia nervosa develops in three phases, often preceded by picky eating and digestive problems in childhood. In Phase I the patient develops an increased consciousness about physical appearance, coupled with a loss of self-esteem, and begins dieting and exercising to lose weight. While these beliefs and behaviors have become increasingly the norm among adolescent women in developed countries, in certain people it progresses to Phase II.
During Phase II (frank AN) the person develops an "anorectic attitude": an unreasonable fear of eating coupled with pride in the ability to loss weight. Restriction of food intake begins with "fattening," "dangerous" foods such as carbohydrates and fats, while other foods, particularly vegetables, are viewed as "safe." In an effort to rationalize their restrictions, patients may develop a sophisticated fund of nutritional knowledge. They may delude parents or other caretakers into believing that they are eating when in fact food may be hidden or vomited up. Patients may also become obsessed with preparing foods, which they then refuse to eat. Some patients may have episodes of binge eating with or without purging in addition to restriction. Patients with this form of anorexia nervosa are more likely to be depressed, suicidal, and self-harming.
Patients may persist in the belief that they are eating a lot when in fact they eat very little. Sensations of hunger and satiety are impaired, with the result that these two states become confused. Further, delayed gastric emptying due to developing malnutrition may contribute to the perception of fullness after consumption of only small amounts of food. Eventually the person may reject all or nearly all foods.
The "anorectic attitude" may be self-amplifying, in that starvation itself may lead to abnormal attitudes towards food. Semistarved persons who are otherwise in good health also develop an obsession with food, linger for hours over a meal, and may feel that once they start eating, they will not be able to stop. For persons with AN, the thought that they may not be able to stop may be a terrifying prospect, confirming their worst fears about their inability to control their appetite.
The types of food that a person with AN likes appear to be normal when ascertained by questionnaire; however, a dislike for high-fat and low-carbohydrate foods is revealed. Taste testing suggests that persons with AN have an abnormally high preference for highly sweet tastes, coupled with a dislike of fatty foods. In this phase, the person may use laxatives and enemas, in the belief that these procedures will prevent absorption of ingested food, and also because anorexics may judge themselves to be constipated since the severely reduced food intake leads to formation of smaller than normal amounts of feces. Laxatives and starvation-induced changes in gut motility lead to both constipation and complaints of abdominal pain. Patients may abuse diuretics in an attempt to lose weight, although their effect is confined to water weight loss.
Patients may participate in extreme physical activity, preferably carried out alone, although it may be expressed in organized group activities such as ballet or athletic performance. This physical hyperactivity is in direct contrast to the inactivity seen in starving subjects without AN.
Depression, anxiety, obsessional traits, perfectionism, and rigidity in thinking are all found in patients in Phase II of AN. The states are often associated with social isolation.
During Phase II, nutritional status may deteriorate steadily, and if untreated, patients may not enter the recovery phase, Phase III. Death may occur from cardiovascular collapse due to starvation and electrolyte imbalance, or due to too rapid refeeding, as well as suicide. As many as 5 percent of patients may die of AN in the acute phase, and 20 percent on long-term follow-uphe highest mortality rate for a psychiatric condition.
Phase III of this disease, which is attained only with difficulty, and in some cases not at all, is the acknowledgment by the patients that they have starved themselves, and need treatment, coupled with success at alleviating the signs and symptoms of the disease.
Management. The management of anorexia nervosa is complex, requiring a concerted effort on the part of the health care team, including physician, nurse, nutritionist, social worker, and psychologist, as well as the patient and his or her family. Because patients are capable of maintaining a state of denial, it is very difficult to engage the patient into the care process. Often the patient has to be in a state of collapse before intervention is even tolerated. Indications for hospitalization are weight loss below 40 percent of normal weight; orthostatic hypotension (low blood pressure when standing); electrolyte (sodium, potassium) imbalance; dehydration; hypoglycemia (low blood sugar); infection; and marked family disturbance.
Treatment involves refeeding and psychological rehabilitation. Refeeding is critical for all patients whose weight is 85 percent or less of that expected. Depending on the severity of the patient's malnutrition, feeding may occur in the hospital, in a clinic setting, or at home. The patient should be hospitalized well before collapse is imminent. Feeding may be oral, naso-gastric, or via intravenous lines. Oral feeding is preferred but some patients may only permit refeeding if it is through a naso-gastric tube, and thus beyond their control. Intravenous feedings may be required if cardiovascular collapse is imminent. No special diets are needed, although concentrated foods may be useful in attaining adequate caloric intakes, and vitamin and mineral supplements are required. Refeeding must be slow, and performed under close medical monitoring, lest the patient develop edema and increased circulating blood volume, which can lead to electrolyte imbalances, anemia, and cardiovascular collapse. Other fatal complications of rapid refeeding include acute stomach or large bowel dilatation. Treatment protocols may also include restriction of exercise, in order to prevent the patient from exercising away the calories. Some patients are adept at finding ways to increase physical activity in the face of exercise restriction, and some patients may become severely agitated when denied the right to exercise.
Psychological treatment varies by health care team and may combine individual, family, and group therapy. Drug therapy may be used, particularly selective serotonin reuptake inhibitors (SSRIs), especially in patients who have regained weight but still are depressed or have obsessive-compulsive symptoms.
The ideal of clinical improvement consists of a return to 90 percent of normal weight, the resumption or initiation of menses in women, normalization of eating patterns, as well as the development of a mature, self-confident outlook, with a normal body image. Few patients attain this ideal. However, the short-term prognosis with respect to weight gain, return of menses, and improvement in outlook is usually good, although the food obsession and inability to control appetite may persist for weeks to months after the patient has regained an adequate amount of weight.
Unfortunately, the long-term prognosis is not so favorable: On the average, about 40 percent of patients recover more or less completely, 27 percent have ongoing endocrine abnormalities or are mildly underweight, 29 percent have a serious recurrence of the disease within a four-year period, and up to 5 percent succeed in starving themselves to death. Those who are over twenty, have prolonged illness, are depressed, have a family history of mental disturbance, have poor family relationships, who use purgatives and diuretics and who follow binges with vomiting have the worst prognosis.
People with bulimia nervosa (BN) have recurring irresistible urges to consume extremely large amounts of food at one sitting (binge). The binge leads to acute feelings of gastric distension, and to sharpening of the fear of becoming fat. To relieve both problems, patients may then proceed to self-induce vomiting or purging. Persons with this condition report a sense of "cleaning out" with vomiting and purging, which may positively reinforce these behaviors. Note that binging without purging comes under the rubric of Eating Disorders Not Otherwise Specified (EDNOS), according to the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM IV), and is described below.
Precipitants of a binge include hunger, being alone, feelings of anxiety, frustration, and worthlessness, and problems with a significant other.
Epidemiology. Like AN, BN primarily afflicts young females from food-rich backgrounds. Its prevalence is unknown because only the most severely affected come to health care. Estimates of the disorder vary from 2.5 to 20 percent of women and 1 to 5 percent of men from the ages of eighteen to twenty-one.
Etiology. The etiology of BN remains unknown. Causes may include a biological predisposition to obesity, depression, and metabolic disturbances (in particular neurohormonal abnormalities, such as abnormalities in the release of gut hormones after eating), coupled with a socially determined desire for thinness, and with bingeing and purging as a group activity, a phenomenon which is becoming increasingly common among women living together, for example in a sorority, or men as part of a team, for example wrestlers.
Families of BN patients have a high prevalence of disorders such as major depression, irritable bowel syndrome, obsessive-compulsive disorder, attention deficit disorder with hyperactivity, and migraine, all of which have been linked to abnormalities in the function of neurotransmitters (chemicals such as norepinephrine and serotonin responsible for sending messages from one nerve cell to the next) in the brain. Levels of monoamine oxidase (MAO, an enzyme responsible for degrading norepinephrine and serotonin) in the blood cell clotting fragments called platelets are lower than normal in a person with BN. Low activity of MAO has been associated with impulsiveness, intolerance of boredom and monotony, and sensation seeking, also commonly seen in bulimic individuals. SSRIs, specifically fluoxetine, which increase
|Physical signs and symptoms associated with anorexia nervosa and bulimia nervosa|
|Anorexia nervosa||Bulimia nervosa|
|Body weight||Usually below normal||May be below normal, normal, or above normal|
|Skin and hair||Dry skin; lanugo (soft down-like hair overgrown on limbs, nape of neck, and cheeks); yellowing of skin (but not whites of eyes) due to excessive consumption of carrots and other carotene containing vegetables||Scratches on the dorsum of the hand due to rubbing of the hand against the upper teeth during self-induced vomiting|
|Teeth||Increased caries due to acid erosion, if patient vomits frequently||Carious due to acid erosion, if patient vomits frequently|
|Water and electrolytes||Low blood potassium, due to vomiting; low blood sodium due to use of laxatives||Low blood potassium due to frequent vomiting|
|Bones||Osteoporosis leading to irreversible vertebral collapse, due to lack of estrogen, and to reduced consumption and to malabsorption of minerals and fat soluble vitamins||Incidence of osteoporosis variable|
|Brain||Brain damage in long-term disease, which may be irreversible||Unknown|
|Gastro-intestinal tract||Slow gastric emptying and slow intestinal transit time, due to starvation||An enlarged stomach with stomach cramping, leading to digestive difficulties; esophageal irritation, due to regurgitation of stomach acid; dysmotility of the esophagus (poor coordination of esophageal movement); slow stomach emptying; injury to the nerves in the gut wall, leading to permanent loss of bowel reactivity; constipation and diarrhea.|
|Metabolic rate||Reduced||Mildly reduced|
|Body temperature||Reduced, with difficulty maintaining a steady body temperature in cold or warm conditions; an occasional patient has an elevated metabolic rate||Variable|
|Cardiovascular system||Hypotension (abnormally low blood pressure); bradycardia (slow heart rate); decreased heart size and cardiac output||Variable, depending on body weight; if body weight is low, the signs are similar to those seen in Anorexia nervosa.|
|Blood||Anemia and leukopenia (low white blood cell count) due to inadequate mineral intake and to starvation||Anemia, due to frequent small upper gastrointestinal tract bleeds, leading to iron loss|
|Causes of death||Cardiovascular collapse, suicide||Cardiovascular collapse, suicide|
responsiveness to endogenous serotonin, are moderately effective in treatment of BN. Abnormalities in other hormones and neurotransmitters, including cholecystokinin (CKK), which is released in response to fat in the intestine and depresses appetite, neuropeptide YY, which is involved in activating appetite, and leptin, are under investigation.
Development, diagnosis, and clinical manifestations. The phases of development of BN are far less clear than those of AN, though, as children, patients with this condition may have had pica (the consumption of nonfood items such as dirt or paint chips), and may have suffered through mealtimes in which there was a great deal of commotion and distress. Some bulimics have been severely abused physically, sexually, or both and may show signs and symptoms of post-traumatic stress disorder, including multiple personality disorder.
It is difficult to determine when bingeing becomes an overt pathological state. Binge episodes may vary from several times daily to once a month or less, and 20 percent of female college students are estimated to have participated at least once in a binge-purge episode.
A binge-purge episode starts with a craving for high-calorie food, usually those high in carbohydrates and fat but low in protein, particularly junk food, which does not have to be cooked. The food is obtained and consumed at one sitting. Thus, a patient may consume a box of cookies, a bag of doughnuts, and a half-gallon of ice cream in a single binge. The binge may then be followed by self-induced vomiting, and/or laxative use. Binges and purges most often occur in private, although there is an increase in group binge-purge episodes among young people who live in communal settings, for example in boarding school or in college. The frequency of episodes increases with increasing stress. Some patients may fast between episodes of bingeing, and may in fact have the binge-eating/ purging form of AN. Other patients may binge without purging.
In BN, eating patterns outside a binge-purge episode are usually characterized by a degree of restrained eating. Nevertheless, when bulimics perceive that they have "violated" the restraint, that is, eaten more than "allowed," they will eat more than a normal person in a test meal situation. Increased postmeal hunger is also experienced by individuals with BN. The restrained eating may therefore be the result of conscious attempts to compensate for the inability to feel satiety, and may be a mechanism for maintaining normal weight in the face of episodes of great hunger and craving. Patients have larger than normal stomachs, which results in both slower than normal stomach emptying and failure to sense fullness, due to excessive relaxation of the stomach, and lower than normal levels of the hormone cholecystokinin (CCK) after a meal. CCK is produced in the intestinal tract in response to fatty food, and signals to the brain that the person has eaten enough. As a result of these changes, the person may fail to be aware of satiety. It may be that once binge-purge episodes have begun, these anatomical and physiological changes will amplify the perceived need to binge, and the consequent need to purge.
In taste tests, persons with BN have a higher than normal preference for very sweet and very fatty foods. Normally, the more a person eats of a sweet food at a single sitting, the less pleasant it becomes. Bulimics may not experience this decrease in pleasantness, as a result of which they may be able to eat large amounts of highly sweet food.
The hypothalamus normally senses when blood glucose levels have risen following food ingestion, which also contributes to the feeling of satiety. Persons with BN appear to have mild insulin resistance, which may prevent their hypothalamus from sensing that rise in blood glucose levels.
Persons with BN are less likely than persons with AN to have a distorted body image, though persons with BN do express an overvaluation of thinness and a fear of becoming overweight. A person with BN may be depressed and agitated, but, unlike a person with AN, usually does not participate compulsively in physical activity.
The most striking complaints and physical and biochemical findings regarding BN are related to the frequent vomiting (Table 1). The ability to taste with the palate may be destroyed due to the stomach acid, although taste by the tongue is little affected. Whether these taste changes contribute to bingeing is unknown.
Management. Bulimia nervosa requires long-term, continuous, nonjudgmental psychological management, nutritional counseling, and rehabilitation, and may include medications, particularly SSRIs. Cognitive behavioral therapy approaches that redirect the person's attention away from food and eating, and which address the person's other psychological problems, are the most successful. Patients may have other conditions, such as drug abuse or personality disorders, which need to be addressed before the eating disorder. Both depressed and nondepressed patients with BN may benefit from medications such as SSRIs. These drugs may help with interpersonal functioning, mood, and anxiety symptoms.
Eating Disorder Not Otherwise Specified
Eating Disorder Not Otherwise Specified (EDNOS) is the term applied to conditions that have some characteristics of the classic eating disorders AN and BN, but which do not meet all the diagnostic criteria outlined in the DSM-IV. Multiple combinations of signs and symptoms are possible, as noted in Table 1. Persons who abuse weight-reduction medications and other regimens, and who are trying to lose large amounts of weight for reasons of beauty rather than health, as well as persons with binge-eating disorder, also fall under this rubric, as do people who use disordered eating behaviors in an attempt to correct the size of what they perceive as abnormally large (or abnormally small) body parts.
Binge-eating disorder is characterized by binges that are not followed by efforts to get rid of the extra calories. It is estimated that about 2 percent of the general population suffers from this condition, with a male to
See also Aversion to Food; Body; Body Composition; Caloric Intake; Eating, Anatomy and Physiology of Eating; Fasting and Abstinence; Hunger, Physiology of; Obesity.
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