Loss of Appetite During Cancer Treatment: Causes and Solutions

## Why Appetite Suffers During Cancer Treatment Loss of appetite (anorexia) during cancer treatment has multiple causes: **Treatment effects:** - Chemotherapy damages taste buds — foods may taste metallic, bitter, or like cardboard - Nausea reduces desire to eat - Mouth sores (mucositis) make eating painful - Constipation or diarrhea disrupts normal eating patterns - Fatigue makes meal preparation feel impossible **The cancer itself:** - Tumors release cytokines (inflammatory proteins) that suppress appetite and alter metabolism - This cancer-driven loss of appetite and muscle mass is called **cancer cachexia** — distinct from simple undernutrition **Psychological factors:** - Anxiety and depression reduce appetite - Anticipatory nausea associated with treatment - Social isolation and disruption of normal meal routines ## Why Nutrition Matters Poor nutrition during treatment leads to: - Unintentional weight loss and muscle loss - Increased fatigue - Reduced ability to tolerate chemotherapy doses - Slower recovery from surgery - Weakened immune function - Impaired wound healing ## Practical Strategies **Eat by the clock, not by hunger** Hunger signals are often blunted during treatment. Eat at scheduled times regardless of whether you feel hungry. Small portions frequently (every 2–3 hours) are better tolerated than three large meals. **Calorie density over volume** When eating feels like work, make every bite count. Choose high-calorie, high-protein foods: - Nut butters - Whole milk, cream, cheese - Eggs - Avocado - Nuts and seeds - Protein shakes (Ensure, Boost, or homemade) **Manage taste changes** - Use plastic utensils if food tastes metallic - Marinate meats in sweet or acidic sauces (metallic taste is often reduced) - Try cold or room-temperature foods — they have less smell and often taste better - Experiment — what tastes bad one week may be tolerable the next **Address contributing symptoms** - Treat nausea aggressively — see our nausea article - Treat mouth sores early with magic mouthwash or prescribed treatments - Treat constipation or diarrhea promptly ## When to Ask for a Dietitian Referral Ask your oncology team for a referral to an **oncology-trained registered dietitian (RD)** if: - You have lost more than 5% of your body weight in the past month - You are struggling to eat or drink enough to maintain energy for daily activities - You have a specific condition requiring dietary management (diabetes, kidney disease, swallowing difficulty) ## Medications That May Help - **Dexamethasone (steroids):** Short-term appetite stimulant; used selectively due to side effects - **Megestrol acetate (Megace):** Appetite stimulant; modest evidence, significant side effects - **Olanzapine:** Evidence for both appetite stimulation and nausea control - **Medical cannabis/dronabinol:** Evidence in some patient populations; discuss with your team