Eating Disorders
Richard E. Kreipe
INTRODUCTION
In 2003, the American Academy of Pediatrics described the role of pediatricians in the identification and management of eating disorders (Box 108.1). Early detection, initial evaluation, and ongoing management in primary care can play a significant role in preventing the illness from progressing and in facilitating referral to interdisciplinary specialists. Within subspecialty care, the management of medical complications, supervision of nutritional rehabilitation, and coordination of the psychosocial and psychiatric aspects of care are often effected by pediatricians, especially those who have experience or expertise in the care of adolescents with eating disorders.
ETIOLOGY AND EPIDEMIOLOGY
The eating disorders anorexia nervosa, bulimia nervosa, and related conditions are best considered final-common pathways that are characterized by body image disturbance that leads to dysfunctional weight control habits and subsequent changes in weight that can result in potentially life-threatening physical and mental health complications. Overestimation of body size or of body parts (generally focused on the abdomen, hips, and thighs) leads to weight control practices intended to either reduce weight or prevent weight gain. Common practices include severely restricting caloric intake (with special attention to the fat content of foods) and behaviors intended to reduce the effect of ingested calories, such as compulsively exercising or purging by inducing vomiting or taking laxatives. Depending on the balance of caloric intake and output, the change in weight may range from extreme loss of weight in anorexia nervosa to fluctuation around a normal to moderately high weight in bulimia nervosa.
Eating disorders have multiple determinants. A combination of biologic, developmental, and sociocultural factors contribute to the predisposition, precipitation, and perpetuation of these disorders, while genetic and twin studies demonstrate a biologic predisposition to both anorexia and bulimia nervosa. Although cultural, social, and environmental factors may play a role, the majority of individuals exposed to these same factors do not develop an eating disorder. A family or personal history of substance abuse or depression is common in patients with bulimia nervosa.
The etiologic factor common to all forms of eating disorders is the sense of control or self-efficacy that individuals gain as a result of their weight control habits. In the case of anorexia nervosa, a societal emphasis on thinness, an athlete’s attempting to achieve a certain weight to improve performance, or peer pressure to achieve a certain “look” can trigger weight loss in a vulnerable individual. Adolescents who develop bulimia
nervosa may initially attempt to restrict their caloric intake by skipping meals or reducing the amount of calories ingested to lose weight, only to trigger binge eating that is followed by compensatory vomiting. Although the act of binge eating and vomiting may seem noxious, patients with bulimia nervosa often describe a feeling of getting “high” when they do so.
nervosa may initially attempt to restrict their caloric intake by skipping meals or reducing the amount of calories ingested to lose weight, only to trigger binge eating that is followed by compensatory vomiting. Although the act of binge eating and vomiting may seem noxious, patients with bulimia nervosa often describe a feeling of getting “high” when they do so.
BOX 108.1 Role of the Pediatrician in the Identification and Treatment of Eating Disorders
Pediatricians:
Need to be knowledgeable about the early signs and symptoms of disordered eating and other related behaviors.
Should be aware of the careful balance that needs to be in place to decrease the growing prevalence of eating disorders in children and adolescents. When counseling children on risk of obesity and healthy eating, care needs to be taken not to foster overaggressive dieting and to help children and adolescents build self-esteem while still addressing weight concerns.
Should be familiar with the screening and counseling guidelines for disordered eating and other related behaviors.
Should know when and how to monitor and/or refer patients with eating disorders to best address their medical and nutritional needs, serving as an integral part of a multidisciplinary team.
Should be encouraged to calculate and plot weight, height, and body mass index using age- and gender-appropriate graphs at routine annual pediatric visits.
Can play a role in primary prevention through office visits and community- or school-based interventions with a focus on screening, education, and advocacy.
Need to be aware of the resources in their communities so they can coordinate care of various treating professionals, helping to create a seamless system between inpatient and outpatient management in their communities.
Footnote
Modified from
American Academy of Pediatrics, Committee on Adolescence. Identifying and treating eating disorders (Policy Statement). Pediatrics 2003;111(1):204.
Eating disorders are not distributed uniformly in the population. More than 90% of patients are adolescent white females from higher-income families, but patients can be of any sex, race, age, or social stratum. As many as 1% of teenage females develop anorexia nervosa, and as many as 5% of older adolescent and young adult females develop symptoms of bulimia nervosa. Less than 10% of patients with eating disorders are male.
Pathogenesis
As previously noted, eating disorders do not have a single pathogenetic mechanism, but most commonly develop in females in relation to various developmental struggles encountered during adolescence. Halmi has noted that eating disorders frequently begin with dieting, which may be transformed into a full-blown disorder by antecedent conditions of biologic vulnerability, premorbid psychological characteristics, family interactions, and social climate. These unhealthy habits serve as a coping mechanism that lessens the negative effects of associated psychosocial problems with which the adolescent may be struggling. Researchers are just beginning to understand the biologic basis for how dieting, exercise, amenorrhea, and weight loss may be used to cope with the developmental demands of adolescence.
Factors predisposing an individual to develop an eating disorder include (1) being female; (2) possessing traits such as perfectionism, obsessive/compulsiveness, or moodiness; (3) having low self-esteem; (4) engaging in activities that place a high value on thinness, such as classic ballet or modeling, or in which the body is exposed during competition, such as gymnastics, track, or swimming; and (5) being in a weight-conscious environment.
There also appears to be genetically based, biologic vulnerability predisposing individuals to develop an eating disorder. International, multisite studies of families with more than one member having an eating disorder has provided evidence for linkage on chromosome 1 and 10 for anorexia and bulimia, with evidence of candidate genes that may contribute to vulnerabilities for these disorders, including traits such as perfectionism, orderliness, low tolerance for new situations, maturity fears, low self-esteem, and overall anxiety. The clinical relevance of genetic predisposition for an individual is probably similar to that for depression. That is, individuals at high genetic risk, based on possessing one or more relevant genes shared with family members who also have an eating disorder, might never develop an eating disorder themselves, but would be more vulnerable to develop one if they were to diet intensively or to live in an environment that emphasizes dieting and thinness. As is true of most conditions with a genetic component, biology and the environment are both important and interact with each other.
Because eating disorders most commonly appear in the second decade of life, when adolescent developmental issues are prominent, the precipitating factors for eating disorders often relate to biologic (sexual maturation), psychological (development of abstract thinking and the emergence of adult psychological traits), and social changes (school transitions, changes in social supports, etc.) of adolescence. In the presence of a predisposed individual, precipitating factors may trigger an eating disorder. Rarely does a single factor give rise to an eating disorder; factors usually accumulate, but the factor most closely related temporally to the appearance of the dysfunctional habits is “blamed” as the “cause” of the eating disorder. However, individuals may engage in weight control habits surreptitiously long before the appearance of the putative causal agent. For example, sexual abuse is commonly identified as a precipitating or causal factor, especially for bulimia nervosa, but sexual abuse generally is associated with a variety of factors that, taken together, create a toxic environment for healthy adolescent development.
Perpetuating factors are those pathogenetic elements that tend to maintain an eating disorder after it develops. Unlike most conditions in pediatrics in which there is a tendency for the patient to want to feel better and comply with treatment, and for healing to occur naturally, eating disorders have a tendency to worsen in the absence of effective treatment. Moreover, patients often resist treatment because accepting it implies losing control as the eating disorder is “taken away” from them. For the pediatric practitioner, the central point is to understand the role that the dysfunctional weight control habits have in perpetuating the dysfunctional cognitive patterns that are associated with eating disorders (dichotomous thinking, overgeneralization, personalization, and magnification). Therefore, the principles of the medical care of the patient, described in greater detail in the section on treatment, needs to focus on improving the physical health of the patient as the foundation upon which effective mental health treatment rests and thereby interrupt the tendency for eating disorders to be self-reinforcing.
BOX 108.2 Key Clinical Findings Associated with Weight Loss
|
CLINICAL MANIFESTATIONS
Anorexia nervosa is characterized by an insufficient and voluntarily restricted caloric intake resulting in weight loss (or failure to gain weight during puberty) that is accompanied by an obsession to be thinner and a delusion of being fat. Patients often restrict intake to less than 1,000 calories per day, are unwilling to accept a body weight greater than 85% of average weight for height, and have a self-concept linked directly to their body weight or image. Weight loss can be extreme. The majority of patients also exercise intensely to accelerate weight loss, but may do so under the guise of sports or dance. Vomiting or laxative use is uncommon, but serious when it occurs.
The key feature of bulimia nervosa is repeated episodes of ingesting large amounts (binges) in a brief period. Since perceptions are subjective, patients may consider eating one cookie to be a “binge.” Binges are followed by compensatory behaviors intended to rid the body of the effects of food: fasting, exercising, or “purging” through vomiting or laxatives. Patients with bulimia nervosa often feel guilt and shame about both binge eating and the compensatory behaviors that follow. Although “getting rid of food” tends to reduce anxiety, the relief is short-lived, and the cycle of behaviors repeats itself in ways sometimes likened to an addiction.
The symptoms and signs experienced by patients with eating disorders are related to the various habits used to control weight. The major symptoms associated with weight control habits are listed in Boxes 108.2 and 108.3. It is important to note that these findings are closely related to the physiologic effect of the habits themselves and are not diagnostic of an eating disorder, per se. The core features that must also be present are dysfunctional eating habits, body image disturbance, and change in weight.
COMPLICATIONS
No organ is spared the effects of the dysfunctional weight control habits and malnutrition, but certain systems deserve mention in the context of pediatric practice. Among patients with eating disorders, the most concerning acute health problems are hypothermia and cardiovascular instability; on a long-term basis amenorrhea obviously is associated with infertility, but when associated with low weight and calcium intake, it also predisposes females to osteoporosis. Because hypothermia can be profound and uncomfortable, temperature should be measured at each pediatric visit. It can be used both as a marker of hypometabolism and as an incentive to increase intake: understanding that ingesting more energy-containing food/beverage will increase metabolism and helping them feel warmer may induce some patients to increase their caloric intake.
BOX 108.3 Key Clinical Findings Associated with Binge Eating and Vomiting
|
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
