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 during and after cancer treatment can help you feel better, maintain your strength, and speed your recovery.

Know your risk. Colorectal cancer and treatment increase the risk for nutrition issues, including malnutrition. Malnutrition occurs when a person is not receiving or absorbing proper nutrition and the right amount of calories and nutrients needed for healthy bodily function. Malnutrition increases the risk for health complications, hospitalizations, and poor quality of life. Tell your healthcare team immediately about any new or worsening side effects or weight loss. For more on colorectal cancer, visit our recommended resources.

Receive ongoing nutrition support. You may need ongoing support from a registered dietitian in your area, especially if you experience ongoing weight loss or severe side effects such as loss of appetite, nausea, vomiting, or diarrhea. Ask your healthcare team for a referral to local registered dietitian who specializes in helping cancer patients. You can also ask your health insurance provider for a referral or use the Find an Expert tool provided by the Academy of Nutrition and Dietetics (AND). (You may also schedule a time to talk to one of our registered dietitians for general education and guidance, but you would benefit most from having a registered dietitian as a member of your healthcare team.)

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 grains. Whole grains provide a good source of carbohydrate and fiber, which help keep your energy levels up. Good sources of whole grains include:

  • Oatmeal
  • Whole wheat breads
  • Brown rice
  • Whole grain pastas

Note: You may be asked by your doctor to avoid whole grain and high-fiber foods if you have an ostomy because these foods can increase output.

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. Read more about Food Safety.

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.

Recommended Resources for Colorectal Cancer

  • Colorectal Cancer Alliance
    Phone: (877) 422-2030
    The Colorectal Care Alliance works to provide support services, to raise awareness of preventive measures, and to inspire efforts to fund critical research. They provide support groups, online chats, education, a peer-partnering program, and financial assistance.
  • Colorectal CareLine
    Phone: (866) 657-8634
    The Colorectal CareLine counselors offer assistance to patients who have been diagnosed with colorectal cancer and are seeking education and access to care. Colorectal CareLine is a division of Patient Advocate Foundation’s Case Management Services.
  • Fight Colorectal Cancer
    Fight Colorectal Cancer works to empower and activate a community of patients, fighters and champions to push for better policies and to support research, education and awareness for all those touched by colorectal cancer. On their website, you can find education information about colorectal cancer.
  • United Ostomy Associations of American, Inc.
    Phone: (800) 826-0826
    United Ostomy Associations of American, Inc. (UOAA) provides education information about ostomies and offers support, resources, and support groups for patients.

For more resources, visit our Recommended Resources page.