When you get diagnosed with cancer, you probably feel quite vulnerable and often have a million thoughts and concerns running through your head. 

One such concern may be maintaining a healthy weight. You may have experienced some unintentional weight loss recently as a result of your cancer. Due to the side effects of some cancer treatments, you may continue to lose weight. Here’s why that happens—and what foods you should be eating as a cancer patient to keep your body strong and prevent malnourishment and dehydration.

Can Cancer Cause Weight Loss?

Yes, people with cancer may experience unintentional weight loss because:

• Cancer cells need more energy than healthy cells, which requires your body to burn more calories
• Cancer cells may prevent your body from properly absorbing nutrients from food 
  
  

Can Cancer Treatment Cause Weight Loss?

Yes, certain cancer treatments, such as radiation and chemotherapy, have side effects that can lead to weight loss. These include:

• Nausea and vomiting, which makes it hard to keep food down and may lessen your appetite
• Diarrhea, which causes your body to lose valuable nutrients before it gets the chance to absorb them
• Constipation, which is uncomfortable and can make you want to avoid eating
• Changes in taste and smell, which can make food unappealing
• Mouth sores, which can make eating painful
• Dry mouth, which can make it difficult to swallow your food
• Fatigue, which can lead to you becoming more sedentary—and ultimately less hungry throughout the day
• Swollen abdomen as a result of ascites, which happens due to pressure from tumors and can reduce your appetite
  
  

Does It Matter What Cancer Patients Eat?

Yes, it matters what cancer patients eat. When fighting cancer, you need as much strength as your body can provide. Consuming enough calories from nutrient-rich food helps to:

• Maintain your strength and energy
• Ease inflammation in your body
• Boost your immune system 
• Make your body more receptive to treatment
  
  

What Foods Should Cancer Patients Eat?

As a cancer patient, you should be taking in enough calories from foods high in vitamins and minerals. Examples include:

• Plant-based protein, like legumes, nuts, seeds and soy products
• Fruits
• Vegetables
• Whole grains, such as quinoa, oats and brown rice
  
  

What Foods Should Cancer Patients Eat If They Feel Nauseous?

When your treatment leaves you feeling nauseous, try eating foods that are easy on your digestive system. These include:

• Bland, starchy foods, such as rice, potatoes, white pasta and white bread
• Foods high in potassium, like bananas, carrots, leafy greens, fish, cucumbers, legumes and chicken
  
  

What Should Cancer Patients Eat If They’re Not Hungry?

Not consuming enough calories or eating nutrient-poor food puts you at risk for malnutrition and dehydration, which weakens you and makes your body less receptive to treatment. To prevent this, try:

• Eating smaller, more frequent meals
• Snacking on calorie-dense foods, such as avocado, nuts, hummus, granola, Greek yogurt and cottage cheese
  
  

What Foods Should Cancer Patients Avoid?

Some foods have very few nutrients and do not provide you with the fuel your body needs to fight cancer. Examples include:      

• Ultra-processed foods, like potato chips, breakfast cereal, candy and packaged snacks
• Processed meat, such as deli meat, sausage and bacon
• Red meat
• Sugary drinks
• Alcohol
  
  

Can Cancer Treatment Cause Weight Gain?

Yes. Some cases of breast cancer, leukemia, lymphoma and multiple myeloma may require treatment with steroids. Steroids can increase your appetite and reduce your metabolism, which can lead to weight gain.

How Can I Prepare for My Cancer Treatment Diet?

Ask your Mercy oncologist to refer you to one of our certified dieticians, who can provide you with in-depth nutrition education and recipe ideas.