What to Eat During Cancer Treatment

If you have recently been diagnosed with cancer or just started treatment, you may wonder what you should eat to help you stay strong while you fight cancer.

Good nutrition is important for everyone but especially for those who have cancer and are undergoing treatment.

“Viewing your diet as a part of your cancer treatment will help you to make the best choices for your own nutrition needs,” says UNC Health dietitian Suzanne Smith, RD, a certified specialist in oncology nutrition. “These choices can have a positive impact on how you feel during treatment and how your body responds to treatment.”

Benefits of Good Nutrition During Cancer Treatment

It is very important to maintain proper nutrition before, during and after cancer treatment to feel the best you can.

Nutritional needs will vary based on the type of cancer you have, your treatment plan and any side effects you experience, says UNC Health dietitian Amanda Holliday, MPH, RD.

“But the most important thing is you get the calories and protein your body needs,” she says. “If you’re not getting the fuel your body requires, it will resort to breaking down muscle tissue to meet these demands, which can be detrimental and impact how you respond to treatment.”

Adequate nutrition during treatment can help you:

  • Maintain your strength and independence
  • Control fatigue so you can continue your normal activities
  • Support your immune system and fight infection
  • Heal and recover faster between treatments
  • Experience fewer side effects related to treatment
  • Maintain your weight and the nutrients in your body
  • Minimize muscle loss
  • Receive your treatments as scheduled, preventing unwanted breaks or delays

“Good nutrition enables patients to recover from their treatments better,” says UNC Health urologic oncologist Hung-Jui (Ray) Tan, MD, MSHPM.

Essential Dietary Needs During Cancer Treatment

Most patients will need extra calories, protein and fluids during treatment, Smith says. Keep these three goals in mind:

  • Eat more protein: During treatment, your body needs more protein to heal tissues and help fight infection. Good sources of protein include fish, poultry, lean meat, eggs, low-fat dairy products, nuts and nut butters, beans, lentils and soy foods.
  • Increase calories: Your body may need more calories during treatment, even if you are not active, according to the American Institute for Cancer Research. These calories can come from carbohydrates, proteins and fats. If you do not meet your calorie needs, you may feel tired and weak. Adequate calories are also essential to maintaining your weight throughout treatment.
  • Drink plenty of fluids: Staying well-hydrated is essential during treatment. Depending on your body size, most patients will need between 8 to 12 cups of fluid a day for proper hydration, but you may need more if you have nausea, vomiting or diarrhea. When you don’t get enough fluids, you’re likely to feel tired and may experience worse side effects. Limit caffeinated drinks to fewer than two per day.

Be Mindful of Supplements and Vitamins

It is important to talk to your medical team about any type of supplement(s) you are taking or considering taking.

Researchers and clinicians believe taking high doses of vitamins, especially antioxidant vitamins (including vitamin C, vitamin E, CoQ10), may change how radiation therapy and some chemotherapy drugs work, but they often disagree about whether the changes are helpful or harmful. Also, supplements are not regulated the way medications are.

“When we’re getting high doses of compounds that can act as antioxidants, it could potentially interfere with the treatment itself because they might be protecting those cancer cells,” Holliday says.

In other words, it is possible that antioxidants may protect tumor cells, in addition to healthy cells, from the damage intentionally caused by treatments. They could reduce the effectiveness of treatment.

Doctors and dietitians don’t worry about people getting too many antioxidants in food; levels of antioxidants in whole foods or drinks are not high enough to interfere with treatment.

If you are eating a balanced diet of fruits, vegetables and whole grains, and your weight is stable, you are probably getting all the vitamins and minerals your body needs during treatment, Smith says.

What To Do When Cancer Makes It Hard to Eat

Sometimes cancer and its treatment can cause problems that can make it difficult to eat, which can increase your risk for poor nutrition. Here are some common side effects and tips for navigating around them.

  1. Taste changes

Sometimes cancer treatments—such as some types of chemotherapy—can cause changes in taste. Here are some things you can do that may help:

  • Try seasoning variations such as marinades, lemon or lime juice, and flavoring extracts such as vanilla or almond.
  • Add fresh herbs to your food.
  • Add gravies and a variety of sauces such as sweet-and-sour, cheese or barbecue to enhance or mask the flavor of your food.
  • Use plastic rather than metal utensils to decrease the bitter or metallic taste of foods.
  • Add vinegar, pickles or relish to meals or dishes.
  • Alternate bites of your meal with bites of tart and twangy flavors to readjust taste buds.

Sometimes treatments may make food taste too salty or too sweet. Offset a salty taste with something sweet or if everything tastes too sweet, try something bland or savory.

  1. Nausea

Nausea is a common side effect of chemotherapy and radiation therapy. If you have nausea or vomiting, choose foods that are bland and easy to digest, such as:

  • Toast, crackers or pretzels
  • Yogurt
  • Sherbet
  • Cream of wheat, rice, oatmeal or grits
  • Boiled potatoes, rice or noodles
  • Skinned chicken that is baked or broiled, not fried
  • Canned peaches or other soft, bland fruits and vegetables
  • Clear liquids: tea, water, bouillon, clear carbonated beverages, sports drinks, or apple, cranberry or grape juice
  • Jell-O or popsicles
  • Carbonated drinks

“Sometimes smells can be bothersome when you’re feeling nauseous,” Holliday says. “Colder foods are better because they’re not going to emit strong aromas.”

  1. Constipation

Chemotherapy, certain medications or lack of exercise may cause constipation. Adding more fiber to your diet may help.

Try these foods with more fiber:

  • Whole-grain breads and pastas, bran cereals
  • Cooked beans, peas and lentils
  • Raw fruits and vegetables
  • Dried fruit
  • Prune juice and hot lemon water

“Increasing your fluid intake can help, too,” Holliday says. “Try prune juice or some warm apple juice, or anything warm to help to stimulate your gut.”

  1. Diarrhea

Chemotherapy, radiation therapy to the lower abdomen or use of antibiotics can cause diarrhea.

“If you’re experiencing diarrhea, cut back on more fibrous foods and incorporate soluble fibers such as the fiber in applesauce, bananas and oats, because they help absorb that extra fluid, which slows things moving through the gut,” Holliday says. “The soluble fibers also act as prebiotics, so they help nourish the healthy bacteria in the gut.”

If you have diarrhea, be sure to drink plenty of room-temperature liquids to prevent dehydration and limit caffeinated beverages.

Here are some foods to try:

  • Cream of wheat, oatmeal, and plain rice and corn cereals
  • Canned fruits, nectars and applesauce
  • White rice, pasta and potatoes without skin
  • Sandwiches on white bread
  • Soups without cream
  • Cheese and crackers, graham crackers and peanut butter
  • Eggs
  • Jell-O and popsicles
  • Caffeine-free soda and herbal tea
  1. Painful swallowing or loss of appetite

For head and neck cancer patients receiving chemo or radiation, it can be very painful to swallow. Other problems such as pain, nausea, vomiting, diarrhea, or a sore or dry mouth may make eating difficult and cause you to lose interest in eating.

“Try soft foods or a more liquid-based diet such as heavy soups or milkshakes,” Holliday says. “Sometimes you might have to rely on nutritional supplement beverages such as Boost and Ensure if eating other food is difficult.”

Depression, stress and anxiety can also cause loss of appetite. If your appetite is no longer motivating you to eat, try to eat five small meals each day by the clock rather than by your hunger cues. Set an alarm every couple of hours to eat something.

Choose high-calorie foods such as avocados, nuts, seeds, puddings, cooked cereals and dried fruits. Dip vegetables in hummus or prepare them with olive oil to add calories.

“Eat multiple small meals or snacks throughout the day and pack each one of those with plenty of calories and protein,” Holliday says.

If you are not eating well during treatment or having difficulty maintaining your weight, you may need to eat high-calorie foods that are not usually recommended.

In other words, if you haven’t had much of an appetite and find yourself craving a cheeseburger or a slice of cake, eat it.

“If you’re craving something, go ahead and enjoy it,” Holliday says.

Enjoying delicious food also can bolster your mental health during this difficult time.

“Don’t deprive yourself. Try to find a little bit of joy while you’re undergoing something as traumatic as cancer treatment,” Dr. Tan says. “The pluses will outweigh the negatives when it’s within moderation.”

If you have questions about what you can eat during cancer treatment, ask your provider to refer you to a cancer dietitian.