Eating Disorders

Eating Disorders Overview - Disorder Lineup

EDs: Persistent eating disturbances impairing health/function. Peak onset: adolescence.

• Anorexia Nervosa (AN): Intense fear of weight gain, distorted body image, severe restriction. BMI < 18.5 (adults) / <5th percentile (children).
• Bulimia Nervosa (BN): Recurrent binge eating + compensatory behaviors (e.g., vomiting, laxatives) ≥1x/week for 3 months.
• Binge Eating Disorder (BED): Recurrent binge eating episodes (distress, lack of control) ≥1x/week for 3 months, no regular compensatory behaviors.
• ARFID (Avoidant/Restrictive Food Intake Disorder): Food avoidance leading to nutritional deficiency/dependence; not due to body image concerns.
• Pica: Persistent eating of non-nutritive, non-food substances (≥1 month).
• Rumination Disorder: Repeated regurgitation of food (≥1 month).
• OSFED (Other Specified Feeding or Eating Disorder): Clinically significant EDs not meeting full criteria for AN, BN, BED, ARFID, Pica, or Rumination Disorder.

⭐ Anorexia Nervosa (AN) has the highest mortality rate of any psychiatric disorder.

Anorexia Nervosa - Starvation's Grip

• Core: Energy restriction → significantly low body weight (contextual, e.g., <5th percentile for age); intense fear of weight gain; distorted body image.

• Types: Restricting; Binge-eating/purging.

• Features: Amenorrhea, lanugo, bradycardia, hypotension, hypothermia, osteoporosis. Psychological: Perfectionism, anxiety.

• Severity (Adult BMI kg/m²): Mild ≥17, Mod 16-16.99, Sev 15-15.99, Ext <15.

• ⚠️ Refeeding Syndrome: Fluid/electrolyte shifts during re-feeding (↓$PO₄³⁻$, ↓$K⁺$, ↓$Mg²⁺$); can be fatal.

  

• Management: Multidisciplinary. Medical stabilization; nutritional rehab (start 25-30 kcal/kg/day, ↑ gradually; monitor electrolytes esp. $PO₄³⁻$); psychotherapy (CBT, FBT). Olanzapine for weight gain.

⭐ Highest mortality of psychiatric disorders; due to medical complications (arrhythmias) or suicide.

Bulimia & BED - The Secret Cycle

• Bulimia Nervosa (BN):

  • Recurrent binge eating + compensatory behaviors (purging/non-purging).
  • Frequency: ≥1x/week for 3 months.
  • Self-evaluation unduly influenced by body shape/weight.
  • Signs: Russell's sign (knuckles), dental erosion, parotid swelling.
  • Complications: ↓K+, ↓Cl-, arrhythmias, Mallory-Weiss tears.
  • Management: CBT, Fluoxetine (60mg/day).

• Binge Eating Disorder (BED):

  • Recurrent binge eating (no compensatory behaviors).
  • Frequency: ≥1x/week for 3 months.
  • Associated with ≥3 features (e.g., rapid eating, eating till full, eating alone, guilt).
  • Marked distress regarding binging.
  • Often linked to overweight/obesity & related comorbidities.
  • Management: CBT, SSRIs, Lisdexamfetamine.

⭐ Hypokalemia is a common and dangerous complication of Bulimia Nervosa due to recurrent vomiting or laxative abuse, potentially leading to cardiac arrhythmias.

ARFID & Peds Focus - Beyond Weight Fears

• ARFID (Avoidant/Restrictive Food Intake Disorder):
  • Persistent eating disturbance → failure to meet appropriate nutritional and/or energy needs.
  • Key: No distress about body weight or shape (differentiates from Anorexia/Bulimia).
  • Manifests as one or more:
    • Significant weight loss / faltering growth (children).
    • Significant nutritional deficiency.
    • Dependence on enteral feeding or oral nutritional supplements.
    • Marked interference with psychosocial functioning.
  • Common underlying reasons: Sensory sensitivity to food qualities, fear of aversive consequences (e.g., choking, vomiting), apparent lack of interest in eating or food.
• Other Non-Weight Focused EDs (Briefly):
  • Pica: Persistent eating of non-nutritive, non-food substances for ≥ 1 month; developmentally inappropriate.
  • Rumination Disorder: Repeated regurgitation of food for ≥ 1 month; not due to a medical condition.
• Pediatric Management Focus:
  • Multidisciplinary team: Pediatrician, dietitian, psychologist/psychiatrist.
  • Nutritional rehabilitation: Restore weight, correct deficiencies.
  • Behavioral therapies: e.g., exposure therapy, CBT for ARFID.
  • Strong family involvement and support.

⭐ ARFID often has an onset in infancy or early childhood and may persist into adulthood; it can be associated with anxiety disorders, ASD, OCD, and ADHD.

High‑Yield Points - ⚡ Biggest Takeaways

• Anorexia Nervosa: Fear of weight gain, distorted body image, low BMI. Key: amenorrhea, bradycardia, osteoporosis.
• Bulimia Nervosa: Binge eating with compensatory actions. Often normal weight. Signs: dental erosion, parotid swelling.
• Binge Eating Disorder: Binge eating WITHOUT compensatory actions; causes distress, often obesity.
• ARFID: Food avoidance (not body image related); causes nutritional deficiency.
• Refeeding Syndrome: Risk in severe malnutrition; monitor phosphate.
• Treatment: Multidisciplinary (medical, nutrition, psychotherapy e.g., FBT).