Eating Disorders

Margaret W. Leung MD, MPH

Tracie Harris MD

Claire Pomeroy MD, MBA

CLINICAL HIGHLIGHTS

Eating disorders include anorexia nervosa, bulimia nervosa, and eating disorder not otherwise specified (NOS). Binge eating disorder, currently classified under eating disorder NOS, is a research diagnosis requiring further study. Early detection, especially by the primary care clinician, is critical to successful intervention.
Psychiatric comorbidities, most commonly depression, anxiety, and substance use disorders, are common in patients with eating disorders.
In one particularly effective treatment model for eating disorders, the primary care clinician coordinates a multidisciplinary approach, including involvement of a nutritionist and a psychiatrist.
Medical management differs between anorexia nervosa and bulimia nervosa. In anorexia nervosa, the primary care physician must be vigilant for physical complications, such as fracture risk related to osteoporosis. Refeeding is an especially high-risk period for physical complications. The patient with bulimia nervosa often has fewer physical complications but some are potentially life threatening, including electrolyte imbalances, which may predispose to serious cardiac arrhythmias.
Medications that lower the seizure threshold (e.g., bupropion) should be avoided in patients with eating disorders.
Treatment of anorexia nervosa focuses on weight restoration, although there is no consensus on specific procedures for refeeding. Cognitive behavioral therapy (CBT) and antidepressants are indicated for the treatment of bulimia nervosa and are commonly used adjunctively in the treatment of anorexia nervosa. Behavioral modifications focused on weight management, such as maintaining a food diary and exposure to normal eating behaviors, are often effective in the management of binge eating disorder.

Clinical Significance

Eating disorders are highly prevalent and often associated with serious physical and psychiatric complications. Of all psychiatric diagnoses, eating disorders have the highest lethality, with anorexia nervosa carrying the highest death rates among eating disorders (1). Moreover, female patients with anorexia nervosa have more than 12 times the mortality rate when compared with women in the general population (2).

The U.S. lifetime prevalence of anorexia nervosa, bulimia nervosa, and binge eating disorder is 0.9%, 1.5%, and 3.5% in women, and 0.3%, 0.5%, and 2% in men, respectively, with the median age of onset ranging from 18 to 21 years old (2). In outpatient settings, eating disorders NOS (which include binge eating disorder) account for 60% of cases, compared with 14% for anorexia nervosa and 25% for bulimia nervosa, suggesting that “classic” presentations of anorexia nervosa and bulimia nervosa may be in the minority (3). The degree to which binge eating disorder contributes to the obesity epidemic in Western cultures is largely unknown. Recognizing eating disorders can be challenging for the primary care clinician because signs and symptoms are often not apparent in the early stages of these diseases.

A compassionate, nonjudgmental therapeutic relationship between the clinician and the patient is essential to maintain regular general medical and psychiatric follow-up. Eating disorders—much like other chronic diseases—vary in severity, relapse, and chronicity over the course of illness. While identification and medical management of eating disorders are core clinical tasks, the primary care clinician’s role also includes encouraging healthy eating to help prevent these disorders. The clinician should emphasize basic nutritional and health education to patients, families, and schools, focusing on healthy eating
habits and healthy weight maintenance. Within clinical practice, the primary care clinician can prevent further medical complications in the high-risk patient by refusing requests for prescriptions for diuretics, laxatives, and appetite-suppressant pills.

Diagnosis

An abbreviated summary of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision (DSM-IV-TR) criteria for anorexia nervosa, bulimia nervosa, binge eating disorder, and eating disorder not otherwise specified is provided in Table 9.1 (4). Binge eating disorder, currently classified under eating disorder NOS, is discussed in the DSM-IV-TR with
descriptive research criteria requiring further study. Nonetheless, as it has relevance as a clinical phenomenon, it is discussed here.

Table 9.1 DSM-IV-TR Criteria

EATING DISORDER (SUBTYPES)	CRITERIA
Anorexia nervosa Restricting Binge eating/ purging	All four criteria need to be met for diagnosis Refusal to maintain body weight at or above normal weight for age and height (<85% expected body weight) Intense fear of gaining weight even though underweight Disturbed thoughts about body weight or shape and denial of symptom severity Amenorrhea
Bulimia nervosa Purging Nonpurging type	Binge eating characterized by ○ Eating an amount of food larger than most people would consume in a similar period of time and circumstance ○ Loss of control during the binge Recurrent inappropriate compensatory behaviors (i.e., exercise, diuretics, laxatives, purging) to prevent weight gain Binge eating and behaviors occur at least twice a week for 3 months Self-evaluation unduly influenced by body shape and weight
Binge eating disorder	Recurrent episodes of binge eating characterized by ○ Eating larger amount of food than normal during short period of time ○ Lack of control over eating during binge period Binge eating episodes are associated with ○ Eating until uncomfortably full ○ Eating large amounts of food when not physically hungry ○ Eating more rapidly than normal ○ Eating alone because of embarrassment by how much food is consumed ○ Feeling disgusted, depressed, or guilty after overeating Binge eating occurs at least 2 days a week for 6 months Binge eating not associated with regular inappropriate compensatory behavior
Eating disorder NOS	Disordered eating that does not meet full criteria for anorexia nervosa or bulimia nervosa
Modified from American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th ed., text revision. Washington, DC: American Psychiatric Publishing, Inc.; 2000.

Table 9.2 Symptoms Reported in Patients with Anorexia Nervosa, Bulimia Nervosa, and Binge Eating Disorder

ANOREXIA NERVOSA	BULIMIA NERVOSA	BINGE EATING DISORDER
Generalized weakness and lassitude Difficulty concentrating Palpitations Abdominal pain and bloating Cold sensitivity Amenorrhea or menstrual irregularities Loss of libido Anxiety Depression	Abdominal bloating Constipation Sore throat Dyspepsia Menstrual irregularities Anxiety Depression	Anxiety Depression Dyspepsia and bloating

ANOREXIA NERVOSA AND BULIMIA NERVOSA

Disordered eating ranges along a spectrum from early preoccupation with food and/or body image to late-stage medical complications. Eating disorders often present with nonspecific generalized symptoms (Table 9.2). A patient with anorexia nervosa does not complain of weight loss per se, though may report fatigue, constipation, abdominal pain, irregular menses, hair and skin changes, and cold intolerance. Persons with bulimia nervosa may report lethargy, abdominal bloating, and constipation but are often secretive about their binge and purging behavior.

The DSM-IV-TR classifies anorexia nervosa into two categories, restricting and binge eating/purging. Anorexia nervosa includes (1) a psychological component of fear of gaining weight despite being underweight, (2) disturbed thoughts about body weight, (3) amenorrhea, and (4) less than 85% expected body weight. The body image distortion in anorexia nervosa is significant in its context and severity with patients overestimating their bodies on a body fat dimension, whereas patients with bulimia nervosa wish to have a body with less fat (5).

Bulimia nervosa is divided into two subtypes, purging and nonpurging. It is characterized by disordered self-perception unduly influenced by body shape and weight concerns, multiple episodes of binge eating over a specific time, and compensatory behaviors that may or may not include purging, such as excessive exercise. In general, anorexia nervosa is an easier diagnosis to make than bulimia nervosa because the former presents with severe weight loss and the desire to lose more weight. Bulimia nervosa is harder to diagnose based on physical appearance because a patient may be either average weight or slightly overweight.

BINGE EATING DISORDER

Binge eating disorder has emerged as a specific DSM-IV-TR research disorder that often presents with symptoms associated with obesity such
as orthopnea from obstructive sleep apnea or polyuria from untreated diabetes mellitus induced by obesity. What distinguishes the obese individual without binge eating disorder from the obese individual with binge eating disorder is the severity of binge eating, not the degree of obesity (6). Binge eating disorder shares many clinical characteristics with bulimia nervosa but lacks the compensatory behavior seen in bulimia nervosa (no purging, etc.).

The patient with disordered eating who does not meet full criteria for anorexia nervosa and bulimia nervosa is diagnosed with eating disorder NOS. A common example is a patient who meets many of the clinical criteria for anorexia nervosa but who has of yet not developed secondary amenorrhea.

GENERAL MEDICAL ASSESSMENT

Monitoring for signs and symptoms of eating disorders should be routine and especially kept in mind when evaluating high-risk populations such as participants in gymnastics, wrestling, and ballet. These individuals often place a high value on a thin body habitus or have rigid weight maxima for competition (7). When there are clinical concerns for an eating disorder, particular components of the history can identify physical complications (8). A complete weight history includes a timeline of maximum and minimum weights, and how much the patient feels he or she “ought to” weigh compared with “standardized” height and weight values. A diet history documents the number and types of past weight loss diets, use of weight loss medications, preoccupations with food, excessive calorie counting, avoidance of “taboo” foods, and types of food consumed, especially in binge eating episodes. An exercise history provides information about the frequency and intensity of exercise. A medication history can elucidate methods of purging with diuretics, ipecac, and laxatives. A specific question about over-the-counter or “borrowed” medication usage may be needed. For women, a menstrual and fertility history is important to determine the impact of the eating disorder on metabolic and endocrinologic homeostasis, such as amenorrhea. Given the high frequency of psychiatric comorbidities in eating disorders, it is important to obtain a psychiatric history and document the presence of depression, anxiety, psychosis, or substance use. Information from the social history can highlight potential risk factors such as a history of trauma or childhood or sexual abuse, which may affect personality functioning and be partially implicated in the genesis of eating disorder in some patients. The family history includes an inquiry particularly about first-degree relatives with eating disorders. The relative risk for full or partial syndromes of anorexia nervosa and bulimia nervosa in patients with a first-degree relative with an eating disorder was 11- and 4-fold, respectively (9).

Pregnancy and diabetes present unique challenges to the primary care clinician providing care to the patient with or at risk for an eating disorder. In pregnancy, hyperemesis gravidarum, a history of eating disorder, or a lack of weight gain in two consecutive visits in the second trimester should prompt a full assessment for an eating disorder (10).
Eating disorder risk increases dramatically in the postpartum period and plateaus 6 months after delivery. An insulin-dependent diabetic may control his or her weight by withholding insulin, thereby increasing the risk for severe hyperglycemia, diabetic ketoacidosis, and long-term complications of diabetes mellitus.

Table 9.3 SCOFF: Validated Screening Questions for Eating Disorders in Primary Care Settings

•	Do you make yourself sick because you feel uncomfortably full?
•	Do you worry that you have lost control over how much you eat?
•	Have you recently lost more than one stone (14 pounds or 6.3 kg) in a 3-month period?
•	Do you belief yourself to be fat when others say you are too thin?
•	Would you say that food dominates your life?
Two positive answers are highly predictive of either anorexia nervosa or bulimia nervosa.
From Morgan JF, Reid F, Lacey H. The SCOFF questionnaire: assessment of a new screening tool for eating disorders. BMJ. 1999;319:1467-1468.

Once a thorough history has been obtained, various screening tools can be applied. The SCOFF is a validated screening questionnaire for eating disorders in the primary care setting (11). Five questions screen for weight loss, attitude about food, sense of control over food, and self-evaluation of body image (Table 9.3). In one study, positive answers to two of the questions yielded a 100% sensitivity and 87% specificity for detecting anorexia nervosa or bulimia nervosa (11).

A thorough physical exam of someone with an eating disorder should be completed, beginning with height and weight. Aberrant vital signs may include bradycardia or orthostatic hypotension. An oral exam may reveal dry mucous membranes, enlarged parotid glands, dental caries, or enamel erosion (Table 9.4). Auscultation of the cardiovascular system may reveal arrhythmias. Mitral valve prolapse may occur secondary to loss of left ventricle muscle mass in anorexia nervosa. The abdominal exam can aid in the detection of pancreatitis and cholecystitis. The genital and gynecologic exam may reveal hypogonadism and related estrogen deficiency. The dermatologic exam may reveal dry, cool skin with lanugo hair. A mental status exam and psychiatric review of systems should be performed to detect the presence of depression, mania, anxiety, psychosis, or other psychiatric comorbidities.

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