Work-Up and Management of Increased Appetite
The work-up for increased appetite should focus on identifying psychiatric causes (particularly depression and eating disorders) and medication effects, as these are the most common reversible etiologies in clinical practice.
Initial Assessment
The evaluation must distinguish between pathological increased appetite and normal physiological hunger. Begin by screening for eating disorders using structured assessment tools, as increased appetite may signal binge-eating disorder or bulimia nervosa 1.
Key History Elements
- Weight history: Document maximum and minimum weights, recent weight changes, and patterns of weight fluctuation 1
- Eating patterns: Assess for binge eating episodes (defined as eating large amounts with loss of control), frequency and timing of eating, food repertoire changes, and percentage of time preoccupied with food 1
- Psychiatric screening: Evaluate for depression, as appetite changes are a core diagnostic feature—some depressed patients experience increased appetite and weight gain 2
- Medication review: Identify psychotropic medications known to increase appetite, including antipsychotics (particularly olanzapine), antidepressants (especially mirtazapine), mood stabilizers, and corticosteroids 3
- Functional GI symptoms: Screen for associated nausea, bloating, early satiety, or other gastrointestinal complaints that may coexist with appetite changes 4
Physical Examination
Measure vital signs (temperature, heart rate, blood pressure), height, weight, and calculate BMI 1. Document physical appearance and signs of recent weight gain or metabolic changes.
Laboratory Assessment
Order a complete blood count and comprehensive metabolic panel including electrolytes, liver enzymes, and renal function tests to exclude metabolic causes 1.
Management Algorithm
For Eating Disorders (Binge-Eating Disorder or Bulimia Nervosa)
If binge eating is present, initiate eating disorder-focused cognitive-behavioral therapy as first-line treatment 1. For adults with binge-eating disorder who prefer medication or have not responded to psychotherapy alone, add either an antidepressant or lisdexamfetamine 1.
For bulimia nervosa, prescribe fluoxetine 60 mg daily in addition to cognitive-behavioral therapy, either initially or if there is minimal response to psychotherapy alone by 6 weeks 1.
For Depression-Related Increased Appetite
Depression-related appetite increases are associated with hyperactivation of reward circuitry in the brain 2. Treat the underlying depression with appropriate antidepressants, avoiding agents that further stimulate appetite (such as mirtazapine) unless weight gain is desired 5, 2.
For Medication-Induced Increased Appetite
Review and consider discontinuing or switching medications known to increase appetite if clinically appropriate 3. Psychotropic medications are common culprits, with appetite stimulation occurring through alterations in brain neurotransmitters and neuromodulators 3.
For Functional GI Disorders
When increased appetite coexists with functional gastrointestinal symptoms, evaluate for anxiety and depression using validated screening tools, as psychological disorders frequently accompany functional digestive disorders 4. Address both the GI symptoms and psychological comorbidities concurrently 4.
Common Pitfalls to Avoid
- Do not dismiss increased appetite as simply "overeating" without screening for eating disorders, as many patients with binge-eating disorder or bulimia nervosa initially present to non-psychiatric providers 6
- Do not focus solely on weight changes as the marker of pathology—eating disorder behaviors and thought patterns may be present regardless of whether weight gain is rapid or gradual 6
- Do not overlook depression as a cause, as it manifests with variable appetite changes (both increases and decreases) and requires specific treatment 2
- Do not attribute increased appetite to lack of willpower or behavioral issues without first excluding psychiatric and medication-related causes 3, 4
Multidisciplinary Coordination
Develop a documented treatment plan that incorporates psychiatric, psychological, and nutritional expertise when eating disorders or complex psychiatric comorbidities are identified 1. This coordinated approach improves outcomes compared to single-provider management.