I Have Colorectal Cancer. What Should I Eat?

How do I make the best food choices throughout cancer treatment?

When you are faced with a colorectal cancer diagnosis, nutrition can be an important part of your journey. Eating a well-balanced diet before, during, and after cancer treatment can help you feel better, maintain your strength, and speed your recovery.

  • Maintain a healthy weight. Treatments such as chemotherapy, radiation, and surgery for colorectal cancer can often contribute to unintentional weight loss. It’s important to avoid excess weight loss during treatment as poor nutrition status can cause decrease the body’s ability to fight infection.
  • Eat small, frequent meals throughout the day. Eating frequent small meals will ensure your body is getting enough calories, protein, and nutrients to tolerate treatment.  Smaller meals may also help to reduce treatment-related side effects such as nausea.  Try eating 5-6 small meals or “mini” meals about every three hours. 
  • Choose protein-rich foods. Protein helps the body to repair cells and tissues.  It also helps your immune system recover from illness. Include a source of lean protein at all meals and snacks.  Good sources of lean protein include:
    • Lean meats such as chicken, fish, or turkey
    • Eggs
    • Low fat dairy products such as milk, yogurt, and cheese or dairy substitutes
    • Nuts and nut butters
    • Beans
    • Soy foods
  • Include whole grain foods. Whole grain foods provide a good source of carbohydrate and fiber, which help keep your energy levels up. You may be asked by your doctor to avoid whole-grains and high-fiber foods while an ostomy is in place because these foods can increase output. Good sources of whole grain foods include:
    • Oatmeal
    • Whole wheat breads
    • Brown rice
    • Whole grain pastas
  • Eat a variety of fruits and vegetables every day. Fruits and vegetables offer the body antioxidants, which can help fight against cancer. Choose a variety of colorful fruits and vegetables to get the greatest benefit.  Aim to eat a minimum of 5 servings of whole fruits and vegetables daily.
  • Choose sources of healthy fat. Avoid fried, greasy, and fatty foods, Choose baked, broiled, or grilled foods instead. Healthy fats include:
    • Olive oil
    • Avocados
    • Nuts
    • Seeds
  • Limit sweets and added sugars. Foods high in added sugars like desserts and sweets provide little nutritional benefit and often take the place of other foods that are better for you.
  • Stay hydrated. Drinking enough fluids during cancer treatment is important for preventing dehydration. Aim to drink 64 ounces of fluid daily. Avoid drinking large amounts of caffeinated beverages. Too much caffeine can lead to dehydration.
  • Be observant of changes in bowel habits. Colorectal cancer and treatments can often lead to changes in bowel habits including diarrhea, constipation, bloating, and gas. It is important for you to communicate with your healthcare team any changes in your bowel habits. Changes in your diet or medications may be necessary to manage these side effects.
  • Practice good food safety. Wash your hands often while preparing food.  Use different knives and cutting boards for raw meat and raw vegetables.  Be sure to cook all foods to their proper temperature and refrigerate leftovers right away.
  • Talk to your healthcare team before taking any vitamins or supplements.  Some medications and cancer treatments may interact with vitamins and supplements.  Choose food first as the main source for nutrients. 
  • Drink alcohol in moderation, if at all.  Alcohol may contribute to dehydration, can lower the abilities of your immune system, and provides no beneficial nutrients.
  • Most importantly, know that your cancer journey is unique to you and your treatment. You may experience side effects that affect your ability to follow these suggestions. If you are struggling with any side effects, such as loss of appetite, nausea, diarrhea, vomiting, or any other nutrition concerns, your needs may be different.  A registered dietitian at PearlPoint Cancer Support can suggest nutrition guidelines that will be appropriate for your cancer journey – contact us at guidance@pearlpoint.org to learn more about our FREE services.