Avoidant/Restrictive Food Intake Disorder

Overview

"Anorexia Nervosa", "AN"

  • Lifetime prevalence is 0.3%, but it is 3 times more common in females than males.

  • There are 2 main types: (1) Restricting, and (2) Binge-eating

Main Concepts:

  • BMI < 18.5 kg/m2

  • Intense fear of weight gain

  • Distorted views of body weights and shape

Notable Features:

  • Mental illness with the highest associated mortality (5 - 20% of anorexic patients die)

High Yield:

  • Patients below 20% ideal body weight (for age, gender, development) should be hospitalized for management. Otherwise, patients can be treated on an outpatient basis.

  • Avoid refeeding syndrome (can lead to: acute gastric dilation, fluid retention, CHF, cardiac arrhythias, rhabdomyolysis, and death)

Other:

Definition


Diagnostics

Associated lab abnormalities:

  • Reduced thyroxine

  • Elevated liver enzymes

  • Elevated cholesterol

  • Carotenemia (elevated serum carotenoids of unknown etiology is associated with AN)

  • Elevated BUN

  • Elevated creatinine

  • Abnormal Hgb and Hct

According to a paper by Dr. Joanne Curran-Celentano and Dr. John W. Erdman, Jr., published in the April 1993 edition of Nutrition Research, elevated serum carotenoids (carotenemia) seen in AN patients appear to be associated with impaired thyroxine expression. Serum betacarotene (provitamin A carotenoid) levels remained elevated in anorexics in a background of low T3, despite being placed on carotene-free diets, which, along with other research, suggests vitamin A and thyroid hormone interactions at the level of gene expression. [link]

Assessment

  • Assess labs

  • Weigh patient

  • Obtain bone density scans

Management

The first step in treatment is to establish the patient's cooperation with the treatment plan. Establish a strong therapeutic alliance with the patient.

The treatment itself depends on a multidisciplinary approach.

Treatment modalities:

  • Cognitive behavioral therapy (CBT) (replace a behavior with a more adaptive one)

  • Family therapy (involve social supports)

  • Supervised weight gain programs (nutritional rehabilitation)

  • Some antidepressants may be used as adjuncts to promote weight gain (e.g. paroxetine, mirtazapine)

    • Be aware that other antidepressants may promote weight loss

Consider using the antipsychotic olanzapine if there is no response to CBT and nutritional rehab, as it can typically cause weight gain.

Resources