colon cancer diet
Copyright: Johnny Greig

Your colon is a key player in your digestive system, which processes and delivers nutrients throughout your body to keep you strong and healthy.

As such, eating well and maintaining a nutritious diet is one of the best ways you can prepare for and recover from colon cancer treatments.

Here are some key tips for building a diet plan that will help keep your colon in the best shape possible before and after treatment.

People with cancer generally have increased nutrient needs, including an increased need for total calories and protein. Plus, consuming a nutrient-dense diet can help support your health and keep your body and immune system as healthy as possible.

Additionally, cancer treatments like chemotherapy can be extremely difficult on your body, as they sometimes destroy healthy tissue, not just cancerous tissue. To rebuild strength, experts say there are some key areas to pay attention to.

“In general, cancer patients aren’t receiving adequate calories or protein. Meeting minimum calorie and protein needs is essential to maintaining a healthy immune system and preventing further infections throughout the body,” says Puja Mistry, a Texas-based licensed and registered dietitian.

People with colon cancer may need to consume extra calories and protein, and may need to supplement with certain nutrients to prevent deficiencies.

What’s more, studies have shown that eating a high fiber diet may help reduce the risk of death in people with colon cancer.

It’s often recommended that people with colon cancer eat smaller, more frequent protein-rich meals to ensure they’re getting the energy they need.

Eating smaller, more frequent meals may also help if you’re experiencing treatment-related side effects like nausea.

However, it’s important to work with your dietitian to come up with a dietary plan that works best for your specific needs and health status.

You can also choose foods and drinks that are room temperature or colder to help with any nausea. Avoiding rooms with cooking smells and having someone else prepare meals for you can also be very helpful.

The first step to creating a custom diet plan, says Mistry, is to think about your daily routine: What do you normally eat every day? How often? Based on this, you can make modifications that make sense for you.

It’s important to remember that everyone’s current health situation, dietary restrictions, and capabilities are unique.

For example, take into account how well you’re able to chew and swallow, what symptoms you’re experiencing, and any food allergies or intolerances you may have.

If you need help, your doctor and dietitian can also work with you to build a diet plan based on your individual needs.

If possible, try adding fresh fish into your meal plans one to three times a week. Fish is full of protein and omega-3 fatty acids, which are both essential for people fighting colon cancer.

Fruits and vegetables are excellent additions to your pretreatment diet plan as they contain vital vitamins and antioxidants. Foods with skin, including nuts, raw fruits, and vegetables, may not be recommended before surgery, though.

Other foods and snacks you can eat before surgery include bland foods like:

  • baked chicken
  • buttered noodles or rice
  • crackers
  • individually wrapped string cheese

To help clean out your colon, your doctor may recommend a clear liquid diet for 12 to 24 hours before your surgery. This may include:

  • broth
  • clear fruit juice
  • gelatin
  • plain coffee

What you shouldn’t eat before surgery

The following are some high fiber foods the American Cancer Society recommends you avoid eating before surgery to help rest your bowels:

  • beans
  • nuts
  • processed meats and hot dogs
  • brown or wild rice
  • whole grains
  • raw or steamed vegetables
  • raw or dried fruits
  • popcorn

Most chemotherapy or radiation treatments won’t require you to make changes to a healthy diet, unless your eating habits are increasing symptoms, such as nausea or diarrhea.

Make sure to talk with your doctor about what you can eat before treatment, since nutritional needs vary from person to person.

Your doctor may recommend foods that aren’t associated with a healthy diet, such as high fat foods to increase your weight, or milkshakes if you have mouth sores that are preventing you from being able to eat many foods.

Treatment for cancer including chemotherapy and radiation therapy can lead to side effects that increase the risk of dehydration, such as fever and vomiting.

It’s important to keep yourself hydrated to stay healthy and energized. Some people may require intravenous (IV) hydration.

The American Cancer Society recommends that you eat the following foods when you’re undergoing colon cancer treatments:

  • Eat plant-based foods like beans and peas instead of meat a few times every week.
  • Fruits and vegetables are excellent additions to your diet plan as they contain vital vitamins and antioxidants. Citrus fruits and vegetables that are dark green or dark yellow have the most benefits.
  • Instead of three large meals, eat high protein snacks every few hours throughout the day to help reduce side effects like nausea. Protein helps repair your body’s cells and enables your immune system to recover.

Healthy snacks include:

  • Greek yogurt
  • eggs
  • soup
  • hot or cold cereal
  • lean meats, like fish or chicken

Taste changes are common during treatment, which can make foods you usually enjoy displeasing. To help, try adding spices, herbs, and marinades to foods. Make sure to avoid making anything too spicy or salty.

Smoothies and juices are a great way to stay hydrated and incorporate fiber and protein when you lack an appetite or have trouble chewing.

Oncology dietitian Chelsey Wisotsky, RD, CSO, from Savor Health, a personalized nutrition service for people with cancer, suggests blending a smoothie to sip on before your next treatment. Here’s her recipe:

Slow-Down Smoothie


  • 1/2 cup milk or nondairy milk of choice
  • 1 large banana
  • 1/2 cup oatmeal
  • 1/2 tbsp. smooth natural peanut butter
  • sprinkle of cinnamon


Blend together until smooth. For additional protein, add 1 scoop of vanilla pea protein powder.

“This slow-down smoothie is high in soluble fiber, protein, and moderate in fat, which will help manage side effects of diarrhea while providing calories and protein,” Wisotsky says.

“If you are on chemotherapy, which requires you to avoid cold foods, make this smoothie with warm milk,” she adds.

What you shouldn’t eat before chemotherapy or radiation treatment

Certain foods and drinks should be avoided during your colon cancer treatments because they contain substances that could facilitate the rapid growth and spread of cancer cells.

These include the following:

  • foods and drinks high in simple sugars, like sugary desserts and candy
  • foods high in saturated fats and trans fats, like pork, lamb, butter, and processed snacks
  • smoked, pickled, or salt-cured foods
  • greasy, fried foods
  • carbonated drinks, including soda
  • caffeine
  • snacks such as popcorn or acidic foods, which could worsen side effects like diarrhea or a sore throat

It’s best to cut out alcohol and tobacco during treatments as well.

Treatment for colon cancer may weaken your body’s ability to fight infections. To avoid food poisoning, avoid eating undercooked food or any raw foods, such as fruits and vegetables, that haven’t been washed.

Your post-cancer treatment diet should continue to focus on good nutrition to help prevent cancer and other chronic diseases like heart disease, high blood pressure, and diabetes.

Research suggests that colon cancer survivors who eat a diet high in fruits, nuts, vegetables, whole grains, chicken, and fish may live longer than survivors who eat more refined sugars, fats, and processed or red meats.

However, it’s not certain whether this is because of the benefits of a healthier diet or a healthy diet’s effect on colon cancer.

Drinking coffee may also help with recovery. A 2020 study of 1,171 people with advanced or metastatic colorectal cancer found that those who increased their coffee intake to at least four cups a day had a lower risk of disease progression and death.

If your side effects have subsided, you can begin to add back some of your regular foods as you tolerate them. Continue to consume a diet rich in healthy fats, protein, and fiber.

Continue to restrict your alcohol and tobacco use as much as possible.

The American Cancer Society website has many recipes for nutritious meals and snacks, including:

Other healthy choices include a nutrient-dense omelet or a yogurt parfait topped with berries, unsweetened coconut, and sliced almonds.

Whether you’re still dealing with side effects or not, Wisotsky offers two additional snacks you can make at home:

GG Yogurt


  • 1 container of plain nonfat Greek yogurt
  • 4–6 ginger snap cookies
  • 1/2 banana, sliced, if desired


Top yogurt with crushed cookies and sliced banana, and serve.

“The combination of nonfat Greek yogurt and ginger-containing cookies may help patients consume a light meal/snack, which will help to manage nausea, not exacerbate it by eating a large/heavy meal…. [Add] the banana on top for more soluble fiber if you’re also experiencing diarrhea,” Wisotsky says.

High Protein Pancakes


  • 1 large ripe banana, mashed
  • 1 egg
  • 1/4 cup nondairy milk
  • 1/2 cup ground oats or quick-cook oats


Blend together, and add more milk if the batter’s too thick. Makes one large or three small pancakes.

“These pancakes are high in soluble fibers to slow down movement through the GI tract,” Wisotsky says.

“Going through treatment can cause side effects such and nausea and vomiting or diarrhea. Taking in enough water is very helpful. Not only water, but electrolytes are important too. Products like Gatorade, Pedialyte, and Smart Water are helpful electrolyte replenishers.”

Julie Rothenberg, MS, RD, LDN, oncology dietitian