Eating Disorders

Although obesity is a major health problem, restrictive eating disorders are also a serious concern for many adolescents, affecting up to 5% of adolescent and young adult females. Young men also exhibit a growing incidence of weight and body concerns and eating disorders. Existing at the intersection of physical and mental health, eating disorders have serious physical, emotional, and psychiatric effects.

As a provider for adolescent patients, it is critical to screen for eating disorders, consider the differential diagnosis and workup, and understand treatment. Providers have an opportunity to proactively support adolescents in developing healthy relationships with food and their bodies to prevent disordered eating, obesity, and nutritional deficiencies. Educating caregivers about expected growth, necessary adjustments in nutrition requirements, and medical recommendations for nutritional or activity changes can also help provide youth with consistent and positive nutritional messaging. Providers should strive to encourage body positivity, healthy movement, and balanced food choices in all youth, regardless of weight or body mass index (BMI).

DSM-5 Criteria for Major Types of Eating Disorders

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for the major types of eating disorders are as follows:

Anorexia Nervosa

• Restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. Significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected.

• Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.

• Disturbance in the way in which one’s body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.

Bulimia Nervosa

• Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:

  • eating, in a discrete period of time (e.g., within any 2-hour period), an amount of food that is definitely larger than what most individuals would eat in a similar period of time under similar circumstances

  • a sense of lack of control over overeating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating)

• Recurrent inappropriate compensatory behaviors in order to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, or other medications; fasting; or excessive exercise.

• The binge eating and inappropriate compensatory behaviors both occur, on average, at least once a week for 3 months.

• Self-evaluation is unduly influenced by body shape and weight.

• The disturbance does not occur exclusively during episodes of anorexia nervosa.

Binge-Eating Disorder

• Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:

  • Eating, in a discrete period of time (e.g., within any 2-hour period), an amount of food that is definitely larger than what most individuals would eat in a similar period of time under similar circumstances.

  • A sense of lack of control over eating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating).

• The binge-eating episodes are associated with three (or more) of the following:

  • eating much more rapidly than normal

  • eating until feeling uncomfortably full

  • eating large amounts of food when not feeling physically hungry

  • eating alone because of feeling embarrassed by how much one is eating

  • feeling disgusted with oneself, depressed, or very guilty afterward

• Marked distress regarding binge eating is present.

• The binge eating occurs, on average, at least once a week for 3 months.

• The binge eating is not associated with the recurrent use of inappropriate compensatory behavior as in bulimia nervosa and does not occur exclusively during the course of bulimia nervosa or anorexia nervosa.

Avoidant/Restrictive Food Intake Disorder (ARFID)

• An eating or feeding disturbance (e.g., apparent lack of interest in eating or food; avoidance based on the sensory characteristics of food; concern about aversive consequences of eating) as manifested by persistent failure to meet appropriate nutritional and/or energy needs associated with one (or more) of the following:

  • significant weight loss (or failure to achieve expected weight gain or faltering growth in children)

  • significant nutritional deficiency

  • dependence on enteral feeding or oral nutritional supplements

• The disturbance is not better explained by lack of available food or by an associated culturally sanctioned practice.

• The eating disturbance does not occur exclusively during the course of anorexia nervosa or bulimia nervosa, and there is no evidence of a disturbance in the way in which one’s body weight or shape is experienced.

• The eating disturbance is not attributable to a concurrent medical condition or not better explained by another mental disorder. When the eating disturbance occurs in the context of another condition or disorder, the severity of the eating disturbance exceeds that routinely associated with the condition or disorder and warrants additional clinical attention.

Medical Complications

Eating disorders can cause or initially manifest as a range of medical concerns included in the following table:

(Source: Eating Disorders. N Engl J Med 1999.)

Assessment and Workup

Assessment and workup for eating disorders require careful consideration of medical conditions that could lead to weight loss in addition to the major eating disorders noted in the DSM-5. Thoughtful questioning (see examples below) and lab evaluation often rule out overt medical conditions and clarify diagnosis.

1. Plot weight, height, and BMI on growth curve.

• Has the patient deviated from expected growth based on previous growth?

• Has the patient always been low-weighted?

• Compare patient’s current BMI to their prior BMI trajectory for age to estimate percentage of an individualized goal body weight. For example, if a patient’s BMI was consistently 40% for age, their appropriate body weight would follow along that trajectory. This approach can help providers evaluate how concerning weight loss is and how much weight the patient may need to gain back.

2. Obtain history specific to eating disorders.

• Dietary history

  • 24-hour dietary recall with food and portion size

  • history of binge eating: eating that felt out of control, eating to feel better about oneself, feeling bad after binging episode

  • excessive intake of fluids and caffeine

  • avoidance of foods or categories of food (fats, carbs, dessert, etc.)

  • intake of diet products (e.g., laxatives, diet pills, diuretics)

  • Does patient count calories? Do they have a calorie goal?

  • Does patient read nutrition labels?

• Attitude about appearance

  • Does patient consider self too heavy, too thin, or just right?

  • Does patient have a desired weight?

  • Has patient ever lost weight intentionally by eating less, exercising more, or using certain supplements/diet products?

  • Does patient feel a part of their body is fat?

  • How does the patient think everyone else sees them?

• Exercise

  • How much does the patient exercise? How intensely?

• Social history

  • Does the patient use substances that may be contributing to weight loss (e.g., stimulants, nicotine) or exhibit a sign of an underlying mental health disorder?

  • Is the patient sexually active?

  • Has the patient experienced abuse or bullying? Was this related to their weight?

  • Has the patient experienced any major life transitions recently (new school, changes in family, etc.)?

• General

  • How much time is spent worrying about food?

  • How often do they weigh themselves? Is there history of abuse/bullying/shaming?

  • What is patient missing out on due to their eating disorder? Has the disorder cost them opportunities to socialize with friends, play sports, participate in dance, attend school?

  • Is there a family history of eating disorder?

• Physical changes

  • change in frequency or duration of menses

  • feeling dizzy or light-headed in day-to-day activities

  • frequent headaches

  • delay in pubertal development

  • loss of hair or cold intolerance

  • abdominal pain, constipation, or bloating

  • stress fractures

3. Consider physical exam findings.

• general: thin, bradycardia, low blood pressure, low body temperature, orthostasis

• skin: lanugo, dry skin, brittle/diminished hair, calluses on fingers from emesis (Russell sign)

• head, eye, ear, nose, and throat exam (HEENT): parotid gland swelling, dental enamel erosion, cavities

• cardiac: diminished pulse, bradycardia, cool/blue extremities

• abdomen: scaphoid; palpable stool

• sexual characteristics: breast atrophy, hypoestrogenic vaginal mucosa

4. Laboratory evaluation: These tests screen for medical causes of weight loss and evaluate for electrolyte abnormalities associated with disordered eating and purging.

• complete blood count (CBC) with differential

• chem 10 (basic metabolic panel plus calcium, magnesium, and phosphorus)

  • Low potassium, chloride, and bicarbonate levels may be a clue that the patient is purging.

  • Low potassium and bicarbonate levels without low chloride level may suggest gastrointestinal losses (e.g., diarrhea due to malabsorption or laxative misuse).

• thyroid function (thyroid-stimulating hormone [TSH], free thyroxin [fT4], free triiodothyronine [fT3])

• celiac screen (anti-tissue transglutaminase antibody, total immunoglobulin A [IgA])

• electrocardiogram (ECG)

• urine human chorionic gonadotropin (hCG; for patients with amenorrhea)

5. Differential diagnosis

• malignancy: central nervous system (CNS) lesion, leukemia/lymphoma

• psychiatric: depression (with secondary anorexia), anxiety, somatization, substance use, obsessive-compulsive disorder (OCD)

• malabsorption: celiac disease, cystic fibrosis

• chronic infection: HIV, tuberculosis

• endocrine: Addison disease, hyperthyroid

• miscellaneous: bezoar, achalasia, cyclic vomiting syndrome, inflammatory bowel disease

6. Screening tests

• Eating Attitudes Test (EAT-26)

• SCOFF questionnaire

Treatment

The end goal of treatment of eating disorders is to help the patient be able to eat normally without excessive structure, maintain a healthy weight, feel good about their body, and engage in activities without restriction. These goals seem straightforward but can require years to achieve if they are reached at all.

Weight is a critical piece of objective data used to assess progress, making it imperative to standardize its collection. In many clinics, patients are weighed only in underwear and a gown after providing a urine sample. The urine’s specific gravity is often checked to ensure that the patient is not water loaded (a result of drinking excessive water to artificially inflate their weight). Some clinics blind patients to their weight.

Refeeding syndrome is a concern in patients who have lost a significant amount of weight or have been consuming very few calories. In starved or severely malnourished patients, refeeding syndrome refers to metabolic disturbances (hypophosphatemia, hypokalemia, hypomagnesemia) after refeeding with supplemental nutrition due to the body switching from catabolic to anabolic metabolism. Such patients typically require hospitalization and daily electrolyte monitoring (basic metabolic panel with calcium, magnesium, phosphorous) to determine the need for supplementation.

Outpatient: Treatment of eating disorders is best accomplished with a multidisciplinary team, typically involving a physician or advanced practice practitioner, nutritionist, and mental health provider who can support and educate the patient and their family. A psychopharmacologist, school nursing/counseling staff, and extended family members may also be helpful in some settings to provide additional medication expertise or structure to eating. Family-based treatment places parents in charge of feeding their child with support from a family therapist and has shown promising results for treatment of anorexia nervosa, but it requires a strong and committed family unit. Cognitive behavioral therapy and dialectic behavioral therapy may also be good options, particularly for patients with binge-eating/ARFID disorders.

Psychiatric intensive treatment: When the patient is not able to make progress with outpatient intervention, numerous levels of care increase in intensity based on the amount of structure the patient requires, ranging from after-school programs a few times a week to full-day programs to residential programs where patients stay overnight in locked psychiatric units.

Medical hospitalization: Adolescent patients should be admitted to a medical hospital if they are medically unstable or if the family is in crisis. Criteria for hospitalization per the Society for Adolescent Health and Medicine are outlined here.