What is the likely diagnosis and recommended evaluation and treatment for a patient with anxiety‑related loss of appetite, early satiety, and fear of vomiting when eating larger meals, without disordered eating thoughts?

Avoidant/Restrictive Food Intake Disorder (ARFID) with Anxiety-Related Features

This presentation most likely represents Avoidant/Restrictive Food Intake Disorder (ARFID) with prominent anxiety features, requiring multidisciplinary assessment including psychiatric evaluation, dietitian consultation, and consideration of low-dose tricyclic antidepressants or SSRIs for both gastrointestinal and anxiety symptoms. 1

Diagnostic Considerations

Primary Diagnosis: ARFID vs. Functional Dyspepsia with Anxiety

• ARFID should be strongly considered when patients present with food restriction, early satiety, and fear of vomiting without body image distortion or weight/shape concerns that characterize anorexia nervosa 1
• The absence of disordered thinking about food, weight, or body image distinguishes this from classic eating disorders like anorexia nervosa, which requires "intense fear of gaining weight" and "disturbance in the way one's body weight or shape is experienced" 1
• Functional dyspepsia with anxiety comorbidity represents an important differential, as anxiety commonly co-occurs with gastrointestinal symptoms and can perpetuate the symptom cycle 1

Critical Red Flags Requiring Immediate Assessment

• Weight loss and food restriction mandate screening for eating disorders, particularly ARFID, even without typical eating disorder cognitions 1
• Assess for objective features of malnutrition including biochemical disturbances, vital sign abnormalities (bradycardia, hypotension, orthostatic changes), and BMI 1
• Rule out mechanical causes (gastric outlet obstruction, superior mesenteric artery syndrome) and gastroparesis through appropriate testing 1, 2

Recommended Evaluation

Initial Assessment Components

• Complete psychiatric evaluation to characterize anxiety symptoms, assess for comorbid depression, and evaluate trauma history, as these commonly co-occur and influence treatment response 1, 3
• Dietitian assessment is essential early in the evaluation to prevent overly restrictive dietary patterns and assess nutritional status 1
• Screen using validated measures for both anxiety/depression and disordered eating behaviors 1

Medical Workup

• Upper endoscopy (EGD) if alarm features present or to exclude mechanical obstruction 2
• Consider gastric emptying study if functional dyspepsia suspected and symptoms persist despite initial treatment 1, 2
• Laboratory evaluation including CBC, comprehensive metabolic panel, and assessment for electrolyte abnormalities if significant restriction or weight loss present 2, 4

Treatment Algorithm

First-Line Pharmacological Management

For patients with prominent anxiety and gastrointestinal symptoms:

• Low-dose tricyclic antidepressants (e.g., amitriptyline 10 mg once daily, titrated to 30-50 mg) represent first-line pharmacological treatment for functional dyspepsia with anxiety, addressing both visceral hypersensitivity and anxiety symptoms 1
• Careful explanation of the rationale is required, emphasizing that these medications modulate gut-brain signaling rather than treating psychiatric illness per se 1

Alternative approach if mood disorder suspected:

• SSRIs at therapeutic doses should be considered if moderate-to-severe anxiety or depression is present, as low-dose TCAs are insufficient for treating mood disorders 1
• SSRIs may also benefit gastrointestinal symptoms through serotonergic mechanisms, though evidence is less robust than for TCAs 1

Adjunctive Pharmacological Options

• Proton pump inhibitors can be trialed for functional dyspepsia symptoms at the lowest effective dose, though they do not address the anxiety component 1
• Prokinetics (if available) may help early satiety, though efficacy varies and many are unavailable outside Asia 1

Psychological Interventions (Essential Component)

• Cognitive behavioral therapy (CBT) represents first-line psychotherapy for both anxiety disorders and functional gastrointestinal symptoms, with strong evidence for efficacy 1
• Gut-directed hypnotherapy shows efficacy for functional dyspepsia and can be delivered by trained dietitians or psychologists 1
• Exposure-based interventions may be particularly relevant for fear of vomiting (specific phobia component), gradually reintroducing feared foods and portion sizes 3

Dietary Management

• Early dietitian involvement is critical to prevent escalation of restrictive eating patterns and ensure adequate nutrition 1
• Standard dietary counseling should be patient-centered, avoiding overly restrictive approaches that may worsen anxiety around eating 1
• Consider gentle dietary modifications rather than aggressive elimination diets, given the psychological vulnerability 1

Critical Pitfalls to Avoid

Iatrogenic Harm

• Avoid escalating to invasive nutritional support (enteral/parenteral nutrition) in patients with functional symptoms and normal/high BMI, as this risks iatrogenesis without improving quality of life 1
• Do not pursue exhaustive invasive testing in the absence of objective biochemical abnormalities or alarm features 1

Diagnostic Errors

• Do not label as eating disorder if restriction is physiologically driven by altered hunger/satiety cues from anxiety or gastrointestinal dysfunction rather than volitional restriction 1
• However, remain vigilant that ARFID can develop secondary to initial physiological symptoms, creating a maladaptive behavioral pattern requiring eating disorder treatment 1

Treatment Sequencing

• Avoid opioids and surgical interventions for functional symptoms, as these cause harm without benefit 1
• Do not delay psychological intervention while pursuing medical workup—these should proceed in parallel 1

Monitoring and Follow-Up

• Assess treatment response in both physical and psychological domains, as improvement in one without the other indicates incomplete treatment 1
• Monitor weight, nutritional intake, and anxiety symptoms at regular intervals 1
• If symptoms prove refractory despite first-line treatments, consider referral to specialized gastropsychology or eating disorder programs with expertise in ARFID 1