Eating Disorders

=Executive Summary= Three key learning points
 * 1) 1/20 people in the US have an eating disorder.  Because most patients do NOT have physical exam findings, physicians need to be aware of the signs and symptoms associated with eating disorders and screen for them.
 * 2) Anorexia nervosa is difficult to treat.  Typically, patients receive comprehensive therapy which includes CBT, inpatient or outpatient treatment, family counseling. Support groups are less useful.
 * 3) Obesity (BMI > 30 m2/kg) affects 72 million US adults and is treated with diet therapy, exercise, drug therapy and surgical therapy.

=Objectives=

Describe the diagnostic criteria for anorexia nervosa, bulimia nervosa, and eating disorder NOS.

 * Anorexia nervosa
 * Refusal to maintain body weight at or above a minimally normal for age/height
 * Intense fear of becoming fat, even though underweight
 * Disturbance in body image, undue influence of body weight on self esteem, OR denial of seriousness of current weight
 * amenorrhea
 *  bulemia nervosa
 * recurrent episodes of binge eating
 * sense of lack of control over eating during the episode
 * recurrent compensatory behavior to prevent weight gain (ie vomiting, enemas, laxatives, etc)
 * binge/purges occurs at least twice a week for three months
 * self-evaluation / self-esteem unduly influenced by body shape and weight
 * bulemia can be a purging type (self-induced vomiting, laxatives, etc) or nonpurging type where a person has used excessive exercise, fasting, or something similar to limit weight gain.
 * eating disorder not otherwise specified (NOS) - disorders with characteristics of anorexia or bulemia but not a complete match
 * ex: anorexic but has regular menses
 * ex: bulemic behaviors but less than twice per week
 * ex: chew and spit out food without swallowing (isn't technically bulemia)
 * binge eating disorder
 * regular episodes of binge eating in the absence of compensatory behaviors characteristic of bulemia

Define the terms “obesity” and “overweight” for adults in terms of body mass index (BMI).
The prevalence of overweight and obesity is commonly assessed by using body mass index (BMI), defined as the weight in kilograms divided by the square of the height in metres (kg/m2 ). A BMI over 25 kg/m2 is defined as overweight, and a BMI of over 30 kg/m2 as obese.

It's not an objective, but a BMI less than 18.5 kg/m2 is underweight.

List the physical findings that may indicate an eating disorder.

 * Patients usually don't present with a chief complaint of "doc, I have an eating disorder".
 * SYMPTOMS: fatigue, dizziness, low energy, amenorrhea, weight loss or gain, constipation, bloating, abdominal discomfort, heartburn, sore throat, polyurua, palpitation, insomnia.
 * most do NOT have physical signs on examination that will lead to a diagnosis (low sensitivity & specificity)
 * GENERAL: emaciated, sunken cheeks, flat
 * VITALS: bradycardia, hypotension, hypothermia, orthostasis
 * SKIN: dry, lanugo, nail changes, subconjunctival hemorrhage
 * HEENT: sunken eyes, dry lips, gingivitis, loss of tooth enamel
 * Breast atrophy
 * Cardiac: mitral valve prolapse, murmur, arrhythmias
 * Abdomen: scaphoid (an abdomen with a sunken anterior wall), tender epigastrum
 * Extremities: edema, Russell's sign
 * Neuromuscular: diminished deep tendon reflexes

Describe the behavioral interventions for binge-eating disorder, bulimia and anorexia nervosa that have been shown to help patients change their undesirable behaviors.

 * Physicians can motivate patients to change with motivational interviewing
 * Binge-eating
 * Cognitive behavior therapy, psychotherapy, guided self-help is useful for binge-eating disorders
 * support groups are useful for binge-eaters but may be less effective for anorexic patients
 * SSRI's - evidence based with positive studies (equal to CBT)
 * Bulemia
 * Cognitive behavior therapy, psychotherapy, guided self-help is useful for binge-eating disorders
 * SSRIs: modest benefit, antipsychotics promising
 * Anorexia
 * patients with anorexia require specialized outpatient care or hospitalization in the case of severe disease. A multi-pronged approach, including family therapy, nutritional rehabilitation, and close monitoring of progress, is most effective.
 * Antipsycholitcs can be helpful

Describe the medical complications of eating disorders.

 * patients already diagnosed with an eating disorder should be monitored for osteoporosis, dental erosions, cardiovascular/metabolic status, blood pressure

Describe the epidemiology of obesity in the United States.

 * Overweight
 * BMI btw 25.0-29.9 kg/m2


 * Obesity
 * BMI >30.0 kg/m2


 * In US, we have seen a huge increase in obesity rates.
 * The most recent data shows a plateau in the prevalence in obesity in the US
 * 72 million adults are obese – 33.3% of men and 35.3% of women

Describe the recent evidence for obesity treatments such as diet therapy, exercise, drug therapy and surgical therapy.
This is a large topic in itself. A several page discussion is found in [Harrison's Internal Medicine, Chapter 75. Evaluation and Management of Obesity]
 * Diets generally have limited efficacy (5 year --> ~4% loss of body weight)
 * Exercise: Although exercise alone is only moderately effective for weight loss, the combination of dietary modification and exercise is the most effective behavioral approach for the treatment of obesity. High levels of exercise are required.
 * drug therapy: Sibutramine (anorexin) and orlistat (lipase inhibitor) are two FDA approved medications
 * surgery: reserved for the morbidly obese. These procedures generally produce a 30–35% average total body weight loss that is maintained in nearly 60% of patients at 5 years

Demonstrate the ability to obtain dietary and behavioral histories.

 * A good history includes:
 * food intake
 * patient’s emotional state
 * perception of body image
 * avoid patients’ deflections in answering physicians’ question

Describe the role of the physician in treating patients with eating disorders of all types.
Physicians can coordinate care, educate patients and families, assess medical complications, monitor nutritional status, and ensure overall health.

=Links= =References=
 * DSM-5 workgroup on Eating disorders