Has anyone lost 15% of their body weight during treatment and what did you do to start gaining weight during treatment

October 3, 2026Navis AI

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For informational purposes only

This answer was generated by AI grounded in NCCN guidelines and published medical literature. It is not medical advice. Always consult your oncologist or care team before making treatment decisions.

Sources & medical oversight

  • Built by OpenCancer’s team of physician-scientists and cancer survivors.
  • Last updated October 3, 2026. Informational only — not a substitute for your oncology team.

Weight Loss During Cancer Treatment: What Others Have Experienced

This is a really common concern, and yes—many cancer patients experience significant weight loss during treatment. A 15% loss is substantial and worth addressing with your care team.

Why Weight Loss Happens During Treatment

Cancer treatment can cause weight loss through several mechanisms:

  • Chemotherapy/radiation side effects: Nausea, loss of appetite, changes in taste, difficulty swallowing
  • Cancer itself: Some cancers increase metabolism or cause early satiety (feeling full quickly)
  • Stress and fatigue: Treatment is physically and emotionally taxing
  • Nutritional needs increase: Your body needs more calories to heal and fight infection

What Patients Often Try (General Approaches)

Based on what cancer patients commonly report:

Nutritional strategies:

  • High-calorie, nutrient-dense foods (nuts, avocados, olive oil, protein shakes)
  • Smaller, frequent meals instead of three large ones
  • Liquid nutrition supplements (Ensure, Boost) when solid food is difficult
  • Addressing specific side effects (ginger for nausea, zinc for taste changes)

Medical support:

  • Working with an oncology dietitian (this is key—they understand treatment-specific nutrition)
  • Appetite stimulants prescribed by doctors in some cases
  • Anti-nausea medications optimized before meals

Practical adjustments:

  • Eating when appetite is best (often morning for chemo patients)
  • Keeping favorite foods accessible
  • Social eating when possible (appetite often improves with company)

What YOU Should Do Now

Questions to ask your healthcare team:

  1. "Should I see an oncology dietitian? Can you refer me?"
  2. "Are there medications that could help with my appetite or nausea?"
  3. "What's a realistic weight goal during my treatment?"
  4. "Are there specific foods or supplements you recommend for my type of treatment?"
  5. "How much weight loss is concerning enough to adjust my treatment plan?"

Why this matters: According to the American Cancer Society, maintaining adequate nutrition during treatment supports immune function, healing, and treatment tolerance. Significant weight loss can sometimes affect treatment decisions, so your oncology team needs to know.


This information is for educational purposes only. Always consult your healthcare team for personalized medical advice and decisions.

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