Evidence-Based Reviews

Are undiagnosed eating disorders keeping your patients sick?

Current Psychiatry. 2005 December;4(12):65-75

References

1. Reas Dl, Williamson DA, Martin CK, Zucker NL. Duration of illness predicts outcome for bulimia nervosa: a long-term outcome study. Int J Eat Disord 2000;27:428-34.

2. Nielsen S, Moller-Madsen S, Isager T, et al. Standardized mortality in eating disorders—a quantitative summary of previously published and new evidence. J Psychosom Res 1998;44:413-34.

3. Hoek HW, van Hoeken D. Review of the prevalence and incidence of eating disorders. Int J Eat Disord 2003;34(4):383-96.

4. Watson TL, Andersen AE. A critical examination of the amenorrhea and weight criteria for diagnosing anorexia nervosa. Acta Psychiatr Scand 2003;108:175-82.

5. Milos G, Spindler A, Schnyder U. Psychiatric comorbidity and eating disorder inventory (EDI) profiles in eating disorder patients. Can J Psychiatry 2004;49:179-84.

6. Rubenstein CS, Pigott TA, L’ Heureux F, et al. A preliminary investigation of the lifetime prevalence of anorexia and bulimia nervosa in patients with obsessive compulsive disorder. J Clin Psychiatry 1992;53(9):309-14.

7. Becker CB, DeViva JC, Zayfert C. Eating disorder symptoms among female anxiety disorder patients in clinical practice: the importance of anxiety comorbidity assessment. J Anxiety Disord 2004;18(3):255-74.

8. Keys A, Brozek J, Henschel A, et al. The biology of human starvation. Minneapolis: University of Minnesota Press; 1950.

9. Ramacciotti CE, Dell’Osso L, Paoli RA, et al. Characteristics of eating disorder patients without a drive for thinness. Int J Eat Disord 2002;32:206-12.

10. Andersen AE. Males with eating disorders: medical considerations. In: Mehler PS, Andersen AE (eds). Eating disorders: a guide to medical care and complications. Baltimore: The Johns Hopkins University Press; 1999;214-26.

11. Lantzouni E, Frank GR, Golden NH, Shenker RI. Reversibility of growth stunting in early onset anorexia nervosa: a prospective study. J Adolesc Health 2002;31(2):162-5.

12. Napolitano MA, Head S, Babyak MA, Blumenthal JA. Binge eating disorder and night eating syndrome: psychological and behavioral characteristics. Int J Eating Disord 2001;30:193-203.

13. Jacobi C, Morris L, de Zwaan M. Overview of risk factors for anorexia nervosa, bulimia nervosa, and binge eating disorder. In: Brewerton, TD (ed). Clinical handbook of eating disorders: An integrated approach. New York: Marcel Dekker; 2004;183-208.

14. Fairburn CG, Beglin SJ. Assessment of eating disorders: interview or self-report questionnaire. Int J Eating Disord 1994;16:363-70.

15. Garner DM. Eating Disorder Inventory-2 professional manual. Odessa, FL: Psychological Assessment Resources; 1991.

16. Garner DM. Psychoeducational principles in treatment. In: Garner DM, Garfinkel PE (eds). Handbook of treatment for eating disorders (2nd ed). New York: Guilford Press; 1997;145-77.

17. Miller KK, Grinspoon SK, Ciampa J, et al. Medical findings in outpatients with anorexia nervosa. Arch Intern Med 2005;165(5):561-6.

If treating eating disorders’ medical consequences is beyond the scope of your practice, refer the patient for evaluation by a physician with this experience.

Table 3

Common medical complications of binge eating disorder

Obesity (body mass index>30) and related comorbidities:
Hypertension
Diabetes mellitus
Hyperlipidemia
Increased cardiovascular mortality
Obstructive sleep apnea
Degenerative arthritis
Gastroesophageal reflux symptoms and complications

Weight. To quantify an eating disorder’s effect on weight gain or loss, determine the patient’s premorbid, lowest, highest, current, and ideal weight. In diagnosing anorexia nervosa in adults, premorbid weight is the most reliable gauge of “expected” body weight by DSM-IV-TR diagnostic criteria. If premorbid weight is unknown, consider using the Hamwi formula:

Weight for height in women: 100 lbs for the first 5 feet, +5 lbs/inch over 5 feet
Weight for height in men: 106 lbs for the first 5 feet, +6 lbs/inch over 5 feet.

Another option for men and women ages 25 to 59 is to use the midpoint of the appropriate height/weight range in the Metropolitan Life tables.

For adolescents with suspected anorexia nervosa, estimate expected body weight from individual growth curves or standard growth charts posted on the Centers for Disease Control and Prevention Web site (see Related resources).

Note that the DSM-IV-TR weight criterion for anorexia of “less than 85% of expected” is an example, not an absolute cutoff. Anorexia nervosa would be an appropriate diagnosis for a patient who weighs more than 85% of expected weight but has lost substantial weight and meets the other diagnostic criteria.

BMI

Laboratory tests vary, depending on patients’ suspected eating disorders (Table 4). In 214 outpatient women with anorexia, the most common abnormalities were anemia (38.6%), leukocytopenia (34.4%), hyponatremia (19.7%) and hypokalemia (19.7%).¹⁷ With few exceptions, abnormal values are not predicted by the apparent degree of undernutrition.

Table 4

Laboratory studies for patients with suspected eating disorders

For whom	Recommended tests
All eating disorder patients	Comprehensive metabolic panel (electrolytes, glucose, albumin, measures of hepatic and renal function), complete blood count, urinalysis, ECG, TSH
Add for patients with anorexia	Serum magnesium, phosphate, calcium; creatinine clearance; chest radiography; estrogen in women, testosterone in men; DEXA bone density scan; consider echocardiography, brain MRI; screen urine for unreported substances of abuse
Add for patients with bulimia and purging type anorexia	Serum magnesium, phosphate, calcium; DEXA scan if patient is amenorrheic or has history of anorexia; amylase (fractionated, if possible); consider fecal occult blood, urine for electrolytes and laxatives, urine drug screen
Add for patients with binge eating disorder	Fasting blood glucose, fasting lipid profile

From diagnosis to treatment

Talking with patients. Discussing abnormal lab results with patients can be therapeutic. In our experience, recovered patients often report that worry about medical complications was their primary reason to seek treatment for eating disorders.

Relate the patient’s cognitive, mood, and physical symptoms to abnormal eating behavior, then present the eating disorder diagnosis as the beginning of treatment. For example, you could praise Mr. J for his courage in revealing his binge eating and tell him that identifying this problem is the first step toward solving it. Not only can he overcome binge eating, but treatment will also likely improve his mood, weight, and blood pressure.

Eating disorder patients who are medically stable, motivated for treatment, have good support, and are able and willing to come for frequent appointments are good candidates for outpatient eating disorder treatment.

Related resources

For clinicians

Standard growth charts. National Center for Health Statistics. Centers for Disease Control and Prevention. www.cdc.gov/growthcharts.
Brewerton TD. Clinical handbook of eating disorders: an integrated approach. New York: Marcel Dekker; 2004.
Work group on eating disorders. Practice guideline for the treatment of patients with eating disorders (2nd ed.). Washington, DC: American Psychiatric Publishing; 2000. Available at: http://www.psych.org/psych_pract/treatg/pg/eating_revisebook_index.cfm.

For clinicians and patients

Zerbe KJ. The body betrayed: a deeper understanding of women, eating disorders, and treatment. Carlsbad, CA: Gürze Books; 1995.
National Eating Disorders Association. www.nationaleatingdisorders.org.
National Association of Anorexia Nervosa and Associated Disorders. www.anad.org.