Is it true that cancer causes our weight to continue to decrease? Are there any friends here whose weight is still...

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 Changes During Cancer: What's Common and What Varies

Great question—weight changes are something many cancer patients experience, but the pattern isn't always the same for everyone.

What Generally Happens

Weight loss is common, but not universal:

Cancer and cancer treatment can cause weight loss through several mechanisms:

  • Cancer itself may increase metabolism or cause loss of appetite
  • Chemotherapy, radiation, or immunotherapy can cause nausea, taste changes, difficulty swallowing, or mouth sores that make eating harder
  • Hormonal changes from certain cancers or treatments
  • Fatigue that makes meal preparation difficult

However, some patients maintain stable weight or even gain weight, depending on:

  • Type of cancer and treatment
  • Individual metabolism
  • Ability to manage side effects
  • Specific medications (some steroids used in treatment can increase appetite)

The Reality: It Varies Significantly

According to the American Cancer Society, weight changes during cancer treatment are highly individual. Some patients experience significant loss, others maintain weight, and some gain weight—particularly if they're taking certain supportive medications.

Important Context

This is why nutrition support matters: Many cancer centers have oncology nutritionists who can help you:

  • Manage appetite and side effects
  • Maintain adequate nutrition despite treatment challenges
  • Address weight changes proactively

Questions for Your Healthcare Team

If you're experiencing weight changes:

  1. Is my weight change expected with my specific treatment plan?
  2. Should I be concerned about my current weight trajectory?
  3. Would meeting with an oncology nutritionist be helpful?
  4. Are there specific foods or supplements that might help?

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

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