What is the first line of treatment for a patient with an eating disorder, considering a comprehensive assessment and potential co-occurring medical or psychological issues?

First-Line Treatment for Eating Disorders

The first-line treatment for eating disorders is disorder-specific psychotherapy delivered within a coordinated multidisciplinary framework that includes medical, psychiatric, psychological, and nutritional expertise, with treatment selection based on the specific eating disorder diagnosis and patient age. 1, 2

Initial Assessment Requirements

Before initiating treatment, complete a comprehensive evaluation that includes:

• Vital signs with orthostatic measurements (temperature, resting heart rate, blood pressure, orthostatic pulse and blood pressure) to assess cardiovascular stability 1, 2
• Anthropometric measurements including height, weight, and BMI (or percent median BMI for children/adolescents) 1, 2
• Complete blood count to detect anemia, leukopenia, and thrombocytopenia 2
• Comprehensive metabolic panel including electrolytes (sodium, potassium, chloride, bicarbonate), liver enzymes, and renal function tests to identify hyponatremia, hypokalemia, hypochloremia, metabolic alkalosis, and hepatic or renal dysfunction 2
• Electrocardiogram in all patients with restrictive eating disorders, severe purging behaviors, or those taking QTc-prolonging medications 1, 2
• Assessment of co-occurring psychiatric disorders including depression, anxiety, and suicidality, as eating disorders have among the highest mortality rates of any mental illness with 25% of anorexia nervosa deaths from suicide 2, 3

Critical caveat: Normal laboratory values do not exclude serious illness or medical instability—approximately 60% of anorexia nervosa patients show normal values on routine testing even with severe malnutrition. 2

Disorder-Specific First-Line Treatments

Anorexia Nervosa

For adolescents and emerging adults with an involved caregiver: Family-based treatment (FBT) is the first-line psychotherapy, which includes caregiver education aimed at normalizing eating and weight control behaviors and restoring weight. 1, 2 FBT results in a remission rate at 6-12 months of 48.6% versus 34.3% with individual treatment. 3

For adults: Eating disorder-focused psychotherapy that normalizes eating behaviors, restores weight, and addresses psychological aspects including fear of weight gain and body image disturbance. 1, 2

Weight restoration goals: Set individualized goals for weekly weight gain (2.2 to 4.4 lb per week to stabilize cardiovascular health) and target weight for all patients requiring nutritional rehabilitation. 1, 2, 4

Important limitation: No medications are currently approved or effective for treatment of anorexia nervosa. 3, 5

Bulimia Nervosa

For adults: Eating disorder-focused cognitive-behavioral therapy (CBT) combined with fluoxetine 60 mg daily, prescribed either initially or if minimal response to psychotherapy alone occurs by 6 weeks of treatment. 1, 2 Only the 60 mg dose was statistically significantly superior to placebo in reducing the frequency of binge-eating and vomiting. 6 Fluoxetine decreases episodes of binge eating even in those without depression (standardized mean difference = -0.24). 3

For adolescents and emerging adults with an involved caregiver: Family-based treatment should be offered. 1, 2

Binge-Eating Disorder

First-line psychotherapy: Eating disorder-focused cognitive-behavioral therapy or interpersonal therapy, delivered in either individual or group formats. 1, 2, 7

Pharmacotherapy: For adults who prefer medication or have not responded to psychotherapy alone, prescribe either an antidepressant (standardized mean difference = -0.29 versus placebo) or lisdexamfetamine (Hedges g = 0.57 versus placebo). 1, 2, 3

Critical Medical Stabilization Criteria

Patients requiring immediate hospitalization before eating disorder treatment:

• Severe medical complications including severe bradycardia, significant electrolyte abnormalities, or cardiac arrhythmias 2
• Active suicidality, as 25% of anorexia nervosa deaths result from suicide 2
• Acute food refusal or uncontrollable binge eating/purging 4
• Recurrent delirium or severe psychiatric instability that prevents engagement in psychotherapy 8

Refeeding protocol: Initiate slow, cautious refeeding with phosphorus supplementation to prevent potentially fatal refeeding syndrome in severely malnourished patients. 2 Do not attempt rapid nutritional rehabilitation, as this increases the risk of fatal refeeding syndrome and ventricular arrhythmias. 2

Ongoing Monitoring Requirements

• Serial QTc monitoring in patients with ongoing restrictive eating or severe purging, as QTc prolongation predicts risk of sudden cardiac death 2
• Cardiovascular assessment is essential, as up to one-third of deaths in anorexia nervosa are cardiac-related 2
• Suicidality assessment at every visit 2
• Weight and vital signs at each encounter 2

Reassuring note: Most cardiac manifestations of anorexia nervosa are completely reversible with appropriate nutritional rehabilitation, including resolution of bradycardia, normalization of QTc intervals, and restoration of cardiac muscle mass. 2

Common Pitfalls to Avoid

• Do not delay hospitalization based on patient or family denial of illness severity, as eating disorders are life-threatening conditions requiring aggressive early intervention 2
• Do not minimize the importance of multidisciplinary coordination—treatment requires documented, comprehensive, culturally appropriate, and person-centered treatment plans incorporating medical, psychiatric, psychological, and nutritional expertise 1, 2
• Do not use psychotherapy or pharmacotherapy alone when both are indicated—for bulimia nervosa in adults, the combination of CBT and fluoxetine 60 mg daily is the evidence-based approach 1, 2
• Do not assume normal labs mean medical stability—clinical assessment of vital signs, weight trends, and physical examination findings are equally critical 2