Eating Disorders: Anorexia and Bulimia
DescriptionAn in-depth report on the treatment and prevention of eating disorders.
Alternative NamesAnorexia; Bulimia
Many factors contribute to the risk of developing an eating disorder.
In general, eating disorders occur in adolescents and young adults, although one study reported that 5% of cases occurred in children under 12 years old.
Age of Onset for Bulimia. A 1997 survey of high school students by the Centers for Disease Control reported that 4.5% induced vomiting after meals or used laxatives to lose weight. Estimates of the prevalence of bulimia nervosa among young women range from about 3% in adolescents to 10% in college women. Some experts claim that even these percentages grossly underestimate the problem because many people with bulimia are able to conceal their purging and do not become noticeably underweight. For example, a European study detected bulimic behavior in 14.4% of adolescents 14 to 16 years old, with full-blown bulimia observed in 1.8% of girls and 0.3% of boys.
Age of Onset for Anorexia Nervosa. After asthma and obesity, anorexia nervosa is the third most common chronic illness in adolescent women. It is estimated to occur in 0.5% to 3% of all teenagers. Anorexia usually first occurs in adolescence with peaks at 13 to 14 years of age and at 17 to 18 years of age. Over the past 40 years, however, the incidence has been steady in teenagers, but it has increased threefold in young adult women.
Studies typically report that 90% of those with eating disorders are females. However, the prevalence in males appears to be increasing.For example, a 2003 Canadian health survey reported that 20% of the patients were male. A 2000 study of teenagers in Minnesota reported that 13% of girls and 7% of boys reported disordered eating behavior.
When eating disorders occur in young adults, men are more apt to conceal them, so the incidence among males may be underreported. One study of Navy men, for example, reported a prevalence of 2.5% for anorexia, 6.8% of bulimia, and 40% for binge eating.
Studies suggest that the psychiatric and behavioral profiles of men and women with eating disorders are very similar to each other, although there are some differences. Excessive physical activity is more prevalent in males with anorexia. Anorexics tend to have very low sexual interest, although there is a higher rate of homosexuality among young men than women. Sexual preference for men may tend to differ, however, by the specific eating disorders. One study reported that 42% of male civilians with bulimia were homosexual or bisexual while 58% of the men with anorexia were asexual.
Most studies of individuals with eating disorders have been conducted using Caucasian middle-class females. Studies are now reporting, however, that minority populations, including Hispanic- Americans and African-Americans, are significantly affected. There is some indication that African-American girls and young women may be at particular risk for eating disorders because of poor body images caused by cultural attitudes that denigrate the physical characteristics of minorities. In one study, bulimia was equally common among both Caucasian and African American women, although the latter were more likely to binge recurrently, to fast, and to use laxatives and diuretics to control weight. Binge eating may be an even more severe a problem in Hispanic Americans. A 2000 study on Asian women also reported rates of dieting and body dissatisfaction that were similar to those in other cultures, but Asian women had much lower percentages of actual eating disorders.
Living in any economically developed nation on any continent appears to pose more of a risk for eating disorders than belonging to a particular population group. Symptoms remain strikingly similar across high-risk countries.
Income Levels. Oddly enough, within developed countries there appears to be no difference in risk between the rich and the poor. Some studies suggest that those in lower economic groups may be at higher risk for bulimia.
Urban Life. City living is a risk factor for bulimia but it has no effect on the risk for anorexia.
Intelligence. In one sample, people with eating disorders scored significantly higher than average on IQ tests. People with bulimia, but not anorexia, had higher nonverbal than verbal scores.
A 2000 study reported that people with eating disorders tended to share similar personality traits, including low self-esteem, dependency, and problems with self-direction. Researchers have been attempting to determine specific personality disorders or behavioral characteristics that might put people at higher risk for one or both of the eating disorders. Some studies have reported the following personality disorders linked to particular eating disorders:
It should be noted that any of these personality traits can appear in either patients with bulimia or anorexia. Some experts believe that the patient's specific personality disorder, rather than whether they are anorexic or bulimic, may be the more important factor in determining treatment choice.
Avoidant Personalities. Some studies indicate that as many as a third of anorexic restrictors have avoidant personalities. This personality disorder is characterized by the following:
The person with both anorexia and an avoidant personality disorder may develop a behavioral and eating pattern as follows:
In keeping with the avoidant personality, one expert described her anorexic patients as having a total lack of self, well beyond having low self-esteem. In support of this, a 2002 study reported that women with eating disorders were less likely to attend to their own needs and to care for themselves. In other words, they felt "self-less" and experienced guilt if they felt they were promoting their own self-interest.
The process of not eating may become an act of passive revenge on those whose love is always out of reach: "See? I am slowly disappearing, and you will be very sad when I am gone."
Obsessive-Compulsive Personality. Obsessive-compulsive personality defines certain character traits (e.g., being a perfectionist, morally rigid, or preoccupied with rules and order). This personality disorder has been strongly associated with a higher risk for anorexia. These traits should not be confused with the anxiety disorder called obsessive-compulsive disorder (OCD), although they may increase the risk for this disorder.
Borderline Personalities. Studies indicate that almost 40% of people who are diagnosed with bulimic anorexia (losing weight by bingeing and purging) may have borderline personalities. Such people tend to:
Some research has suggested that the severity of this personality disorder predicts difficulty in treating bulimia, and it might be more important than the presence of psychological problems, such as depression.
Narcissism. Studies have also found that people with bulimia or anorexia are often highly narcissistic and tend to:
Accompanying Emotional Disorders
Between 40% and 96% of all eating-disordered patients experience depression and anxiety disorders. Depression, anxiety, or both is also common in families of patients with eating disorders. It is not clear if emotional disorders, particularly obsessive-compulsive disorder (OCD), cause the eating disorders, increase susceptibility to them, or share common biologic cause.
Obsessive-Compulsive Disorder (OCD). Obsessive-compulsive disorder is an anxiety disorder that occurs in up to 69% of patients with anorexia and up to 33% of patients with bulimia. In fact, some experts believe that eating disorders are just variants of OCD. Obsessions are recurrent or persistent mental images, thoughts, or ideas, which may result in compulsive behaviors (repetitive, rigid, and self-prescribed routines) that are intended to prevent the manifestation of the obsession. Women with anorexia and OCD may become obsessed with exercise, dieting, and food. They often develop compulsive rituals (e.g., weighing every bit of food, cutting it into tiny pieces, or putting it into tiny containers). The presence of OCD with either anorexia or bulimia does not, however, appear to have any influence on whether a patient improves or not.
Other Anxiety Disorders. A number of other anxiety disorders have been associated with both bulimia and anorexia.
Depression. Depression is common in people with eating disorders, particularly anorexia. Depression and eating disorders are also linked to a similar seasonal pattern, as indicated by the following observations:
Major depression is unlikely to be a cause of eating disorders, however, because treating and relieving depression rarely cures an eating disorder. The severity of the eating disorder is also not correlated with the severity of any existing depression. In addition, depression often improves after anorexic patients begin to gain weight.
A 2002 study reported that among American teenagers 18% of overweight girls and 6% over overweight boys reported extreme eating disorder behaviors, including use of diet pills, laxatives, diuretics, and vomiting. With the increasing epidemic of obesity in America, such behaviors will only compound the health problems in obese young people.
Body Image Disorders
Body Dysmorphic Disorder. Body dysmorphic disorder involves a distorted view of ones body that is caused by social, psychologic, or possibly biologic factors. It is often associated with anorexia or bulimia, but it can also occur without any eating disorder. People with this disorder commonly suffer from emotional disorders, including obsessive-compulsive disorder and depression. (Some evidence suggests that treatment with fluoxetine (Prozac), a common antidepressant known as an SSRI, helps reduce this problem, even in people without an eating disorder.)
Muscle Dysmorphia. Experts are also increasingly reporting a disorder in which people have distorted body images involving their muscles. It tends to occur in men who perceive themselves as being "puny, which results in excessive body building, preoccupation with diet, and social problems. Such individuals are prone to eating disorders and other unhealthy behaviors, including the use of anabolic steroids.
Excessive Physical Activity
Highly competitive athletes are often perfectionists, a trait common among people with eating disorders.
Female Athletes and Dancers. Women in "appearance" sports, including gymnastics and figure skating, and in endurance sports, such as track and cross-country, are at particular risk for anorexia. Success in ballet also depends on the development of a wiry and extremely slim body. Estimates for episodes of eating disorders among such athletes and performers range from 15% to over 60%.
Male Athletes. Male wrestlers and lightweight rowers are also at risk for excessive dieting. One-third of high school wrestlers use a method called weight-cutting for rapid weight loss. This process involves food restriction and fluid depletion by using steam rooms, saunas, laxatives, and diuretics. Although male athletes are more apt to resume normal eating patterns once competition ends, studies show that the body fat levels of many wrestlers are still well below their peers during off-season and are often as low as 3% during wrestling season. Of concern is a recently recognized body-image disorder, referred to as muscle dysmorphia, which occurs mostly in men who are preoccupied with weight lifting and who perceive themselves as puny.
Men and Women in the Military. Studies also show a higher-than-average risk for eating disorders in men and women in the military. A study of eating behavior on one Army base reported that 8% of the women had an eating disorder, compared to 1% to 3% in the civilian female population.
In general, vegetarianism, with careful planning, is a healthy practice for both adults and adolescents. Studies report, however, that vegetarianism in adolescence may be a risk factor for eating disorders in both males and females. In one study, while vegetarian teens ate more fruits and vegetables, they were also twice as likely to diet frequently, four times as likely to intensively diet, and eight times as likely to use laxatives as their non-vegetarian peers.
This study does not mean that being a vegetarian equates with having an eating disorder. It does suggest, however, that parents with children who suddenly become vegetarian, should be sure that their children are eating a balanced meal with sufficient protein, calories, and important minerals, such as calcium. Parents also might suspect anorexic behavior in their child under certain conditions:
Diabetes or Other Chronic Diseases
According to one survey, 10.3% of teenage girls and 6.9% of boys with chronic illness, such as diabetes or asthma, had an eating disorder. Some recent research suggests an endocrinological link between obesity, diabetes, and eating disorders.
Diabetes. Eating disorders are particularly serious problems for people with either type 1 or type 2 diabetes.
There is a greater risk for eating disorders and other emotional problems for girls who undergo early puberty, when the pressures experienced by all adolescents are intensified by experiencing, possibly alone, these early physical changes, including normal increased body fat. One interesting study reported the following:
This study reported on girls without eating disorders, but it certainly suggests patterns that can lead to eating problems, particularly in girls who go through puberty early.