What are the recommended strategies to increase appetite and nutritional intake in adults with loss of appetite?

Management of Appetite Loss in Adults

Begin by systematically reviewing and discontinuing or reducing sedating CNS medications—particularly opioids, duloxetine, and pregabalin—before considering appetite stimulants, as these drugs are primary contributors to appetite suppression through drowsiness, nausea, and constipation. 1

Step 1: Address Medication-Induced Appetite Suppression First

• Opioid analgesics (e.g., oxycodone) directly impair oral intake by causing nausea, constipation, and excessive drowsiness 1
• Duloxetine and pregabalin contribute to sedation and fatigue that reduce food consumption 1
• Retrospective data demonstrate that reducing or stopping these sedating agents mitigates nutrition-impact symptoms and improves overall intake 1
• Avoid polypharmacy and minimize sedating medications as a foundational strategy 2

Step 2: Treat Reversible Nutrition-Impact Symptoms

Systematically correct the following before escalating to appetite stimulants:

• Chronic nausea and early satiety: Use metoclopramide 2, 1
• Pain: Optimize analgesia while minimizing opioid burden 2
• Constipation: Prescribe laxatives proactively 2
• Depression and anxiety: Treat with antidepressants 2
• Dry mouth, thick saliva, difficulty chewing: These symptoms independently predict reduced intake and weight loss 2

Aggregate symptom burden is an independent predictor of reduced intake, weight loss, and survival, so addressing multiple symptoms simultaneously is critical 2.

Step 3: Implement Non-Pharmacologic Interventions

• Dietary counseling by a registered dietitian improves appetite and should accompany any pharmacologic intervention 2, 1, 3
• Oral nutrition supplements and fish oil supplements (EPA) improve appetite and nutrition outcomes in patients undergoing cancer treatment 3
• Encourage meal preparation by the patient, as this increases appetite and food intake 4
• Provide opportunities to eat in company with a wide variety of foods—a simple strategy that increases intake 4
• Physical therapy and exercise programs may improve satiety sensitivity; long-term activity reduces fasting leptin and glucose, promoting appetite control 5

Step 4: Consider Pharmacologic Appetite Stimulants (Second-Line Only)

Megestrol Acetate (Use with Extreme Caution)

• Reserve for patients with very limited life expectancy only due to severe safety concerns 1
• Improves appetite in ~25% and causes weight gain in ~8% of patients 1
• Major risks: Thromboembolic events occur in 1 in 6 patients; mortality rate is 1 in 23 1
• Weight gain is predominantly fat, not lean muscle mass 1
• Additional toxicities include peripheral edema and adrenal axis suppression 1

Dexamethasone / Corticosteroids

• Provide appetite stimulation comparable to megestrol acetate 1
• Recommend only for patients with life expectancy of weeks to a few months due to cumulative toxicities and diminishing efficacy with prolonged use 1

Olanzapine (Not Currently Endorsed)

• Clinical trials show significant increases in appetite scores (baseline 1–2 rising to 6–8 on a 0–10 scale, p < 0.001) 1
• ASCO does not endorse olanzapine for cancer-related cachexia due to insufficient trial data 1
• When used for psychiatric indications, it is associated with notable weight gain 1

Other Agents (Limited Evidence)

• Mirtazapine and dronabinol have been used in older adults with unintended weight loss, though evidence is less robust 6

Key Pitfalls to Avoid

• Do not initiate appetite stimulants before medication review: Failing to address opioid and duloxetine-related suppression is the most common error 1
• Do not use megestrol acetate as first-line therapy: The 1-in-6 thromboembolism risk and 1-in-23 mortality risk make it appropriate only for end-of-life scenarios 1
• Do not force patients to eat: This is counterproductive, increases nausea/vomiting, and causes patient distress 2
• Do not rely on enteral or parenteral nutrition in advanced cachexia: In most patients with advanced cancer and cachexia, providing additional calories by feeding tubes or intravenously does not improve outcomes 2

Communication with Patients and Caregivers

• Explain that loss of appetite is common in advanced illness and often results from the disease process itself 2
• Emphasize that forcing food intake leads to increased nausea, vomiting, and social withdrawal 2
• Redirect caregivers to provide support through non-food means (massage, lip moisturizer, companionship) rather than pressuring the patient to eat 2
• Refer to a registered dietitian to provide additional opportunities for patients and caregivers to discuss concerns 2

Monitoring

• Track weekly weight, BMI, and percentage of meals consumed to gauge response to therapy 1
• Expect modest improvements: inpatient studies show average ~17% increase in meal intake, with approximately half of patients reporting subjective dietary improvement 1