Nutrition During Cancer Treatment

OncoLink Team
Last Reviewed: July 6, 2017

Benefits of Good Nutrition During Cancer Treatment

Cancer treatments, and sometimes the cancer itself, can make it challenging to maintain a nutritious diet. Side effects like nausea, fatigue, taste changes and dry mouth can impact what you can eat and have an effect on your overall nutritional status. Each cancer patient’s nutritional needs are unique. Your care team, and in particular, your dietitian, can help you identify your nutrition goals and plan strategies to help you meet them.

There are many benefits to maintaining good nutrition during treatment. Some of these include:

  • Combatting fatigue
  • Maintaining your body's store of nutrients and your weight, or at least minimizing weight loss
  • Help in managing treatment-related side effects
  • Decreasing your risk of infection and promoting healing and recovery

Proper nutrition requires eating a variety of foods that provide the nutrients you need to maintain your health. These nutrients include protein, carbohydrates, fat, water, vitamins, and minerals. Each is explained in greater detail below.


Protein: Protein helps to maintain growth and repair body tissue, maintain a proper fluid balance, and to maintain a healthy immune system. Following surgery, chemotherapy, or radiation therapy, additional protein is usually needed to heal tissues and to help prevent infection. Good sources of protein include lean meat, fish, poultry, dairy products, nuts, dried beans, peas and lentils, and soy foods.

Carbohydrates and fats: Carbohydrates and fats supply the body with a majority of the calories it needs. Calories are used by the body for energy. The number of calories each person needs depends on his or her age, size, and level of physical activity. Sources of carbohydrates include fruits, vegetables, breads, pasta, grains and cereal products, dried beans, peas, and lentils. Sources of fat include butter, margarine, oils, nuts, seeds, dairy products, meats, fish, and poultry.

Vitamins and minerals: Vitamins and minerals help ensure proper growth and development. In addition, they allow the body to use the energy (calories) supplied in foods. A person who eats a balanced diet with enough calories and protein usually gets plenty of vitamins and minerals. Your care provider or dietitian may recommend a daily multivitamin and mineral supplement if you are unable to maintain a balanced diet. Do not take any vitamins or minerals without first speaking to your care provider.

Water: Water and non-caffeinated fluids are vital to health. You should consume about 8 glasses of fluid each day. Keep in mind that soups, ice creams, popsicles and water ice are considered fluids. If you do not take in enough fluids or if you are vomiting or have diarrhea, you may become dehydrated. Ask your medical team how much fluid you need each day to prevent dehydration.

Managing Side Effects That Can Affect Nutrition

Poor Appetite

  • Choose foods that will provide the most calories per serving. Avoid diet and low fat foods.
  • Drink high calorie beverages such as juices, fruit nectars, milk, cocoa, malted milk, shakes, smoothies, Ovaltine®, Carnation Instant Breakfast®, and commercial nutritional beverages such as Ensure® and Boost®.
  • Eat small meals throughout the day rather than 3 large meals. Try to eat 5 - 6 mini-meals. Schedule these meals and snacks. Eat a few mouthfuls, even if you aren't hungry.
  • Eat high calorie snacks such as peanut butter, cheese, ice cream, puddings, nuts, trail mix, breakfast bars, cereal, yogurt, cottage cheese, deviled and hard-boiled eggs.
  • Make a smoothie with fruit and ice cream or yogurt (Greek yogurt is even higher in protein than regular yogurt!
  • Carry snacks with you when going to doctors’ appointments or doing errands.
  • Try different foods and drinks. Foods that you dislike one day may be appealing on another day.
  • Don’t be discouraged if foods you always loved don’t appeal to you right now. This is not uncommon during treatment. You may find new foods interesting and again, just keep trying as things can change from day to day.

Taste Changes

  • Rinse your mouth before meals with salt water (1/4 tsp salt with 1 cup water), sparkling water or ginger ale, or brush your teeth.
  • Avoid cigarette or cigar smoking, as this can make taste changes worse.
  • Try making the flavors of your food more powerful with the addition of spices, herbs, marinades, lemon juice, sauces or pickled foods.
  • Choose foods with strong flavors, lemon, for instance (lemon meringue, a lemon marinade, etc.).
  • Avoid any acidic additives if you have mouth sores. While it seems logical that spicy foods should be avoided with mouth sores, research has found that capsaicin (which is derived from chili peppers) can be used to treat pain from mouth sores, so it may be helpful for some.
  • Try to overpower a metallic taste with lemon drops, sugar free hard candy, mints or gum. For those dealing with xerostomia (dry mouth), these can also help stimulate saliva.
  • If a metallic taste is your concern, use plastic utensils and drink beverages from bottles, not cans.
  • Beef is particularly prone to tasting metallic, so you may want to replace it with other forms of protein like chicken, eggs or dairy products.
  • Serve foods cold or at room temperature. This can decrease the foods' tastes and smells, making them easier to tolerate.


  • If you have constipation, try eating high-fiber foods that can stimulate your bowels to move. Examples of high-fiber foods include whole grain breads and cereals, raw fruits and vegetables, dried fruits, seeds, beans, legumes, and nuts. Fiber supplements (like Metamucil) can also be used.
  • Increasing fiber in the diet is often not effective if your constipation is caused by pain medications. In those cases, you should speak to your healthcare provider about a laxative that is right for you.
  • Drink 6-8 glasses of fluid per day. Try warm or hot fluids, especially in the morning.
  • Increase your physical activity as much as possible. Even short walks will help decrease constipation.
  • Attempt a bowel movement at a regular time each day, preferably after breakfast.
  • Prune, apple, peach and pear nectars/juices may be helpful as they have a laxative effective, but the effectiveness varies person to person and they may cause diarrhea.


  • Increase your fluid intake, unless your doctor or nurse tells you not to do so.
  • Rinsing your mouth regularly with one teaspoon of baking soda and eight ounces of water or salt water can help prevent infections and improve healing of a sore mouth and throat.
  • Include foods high in protein such as dried beans, poultry, eggs, peanut butter, meat, fish, and dairy products, such as milk, cheese and yogurt (Greek yogurt is higher in protein than others). Nutritional supplement shakes like Ensure®, Boost® can also provide calories and protein.
  • Avoid hot, spicy, greasy or fried foods.
  • Avoid alcohol.
  • Avoid citrus fruits and juices such as oranges, lemons, limes and tomatoes as these may be too acidic. Try apricots, pears or peaches instead.
  • Avoid hard or coarse foods such as crusty breads, crackers, raw vegetables, potato chips, tortilla chips and pretzels.
  • Avoid carbonated beverages.
  • Try soft foods like puddings, jello, mashed potatoes, soups, etc.
  • Cold treats like popsicles and water ice can be soothing to mouth sores.
  • Eat whenever you are hungry, even if it's not a mealtime.
  • Eat smaller, more frequent meals throughout the day, rather than three large meals. Create a nice environment when eating to stimulate your appetite.


  • Eat bland and easy to digest foods such as chicken, fish, eggs, puddings, mashed potatoes, noodles, rice, yogurt, cottage cheese, cream of wheat, farina, smooth peanut butter, white bread, bananas, applesauce, canned fruit and well cooked vegetables.
  • Avoid dried fruits, cruciferous vegetables (broccoli, cauliflower, cabbage, peas), raw vegetables, whole grains, beans and legumes.
  • Avoid fried and greasy foods, as these can promote diarrhea.
  • Soluble fiber is a type of fiber found in some foods that absorbs fluid and can help relieve diarrhea. Foods high in soluble fiber include:
    • Fruits: Applesauce, bananas (ripe), canned fruit, orange and grapefruit.
    • Vegetables: Boiled potatoes.
    • Breads & pastas: White rice and products made with white flour.
    • Cereals: Oatmeal, cream of rice, cream of wheat and farina.
  • Eat small amounts of food 5-6 times throughout the day, instead of three large meals.
  • Add nutmeg to foods in order to slow down the movement of material through the intestines.
  • Drink at least 6-8 glasses of uncaffeinated fluid per day to prevent dehydration. Besides water, consider fluids that replace minerals and electrolytes lost through diarrhea such as sport drinks (Gatorade®) or soup broth.
  • Clear liquids may be easier to tolerate. Try clear fruit juices like apple or cranberry, ginger ale and jell-O.
  • Avoid caffeine (cola, coffee, tea), alcohol, milk or milk products, chocolate, dried fruits, beans or popcorn as well as fatty, fried, greasy or spicy foods.
  • Avoid very hot and cold beverages.


  • Drink 6-8 glasses of uncaffeinated fluid per day to prevent dehydration.
  • Eat dry, bland foods, such as crackers, toast, cereals, pretzels and ginger cookies.
  • Eat cold foods such as cereals, salads, cold cuts and desserts. The smell of hot foods can exacerbate nausea.
  • Eat 6 small meals throughout the day, instead of 3 large meals.
  • Chew food well.
  • Try peppermint or ginger tea, flat soda or gingerale.
  • Try to have others prepare your meals.
  • Rinse your mouth out frequently and before eating to avoid an unpleasant sour taste.
  • Suck on mints, hard candy, or ginger candy.
  • Loosen clothes, get fresh air and sit upright for 1-2 hours after eating.
  • Eat in cool rooms with fresh air.
  • When you have stopped vomiting, try eating easy-to-digest foods such as clear liquids, crackers, gelatin, and plain toast

Dry Mouth or Thick Saliva

  • Keep water handy to keep the mouth moist at all times. Sip water or spray it in the mouth regularly.
  • Rinse with salt and baking soda solution 4-6 times a day (1 tsp. salt, 1 tsp. baking soda, and 1 quart of water).
  • Avoid mouthwashes with alcohol and alcoholic beverages as these can further dry and irritate the mouth.
  • Chew sugar free gum/suck on sugar free hard candy or drink diet ginger ale to stimulate saliva production.
  • Avoid liquids and foods with high sugar content.
  • Limit coffee, tea and alcohol as these will make dry mouth worse. Caffeine products such as coffee, tea and colas also act as diuretics.
  • Avoid dry foods, such as bread, dry meat, toast, crackers, and snack foods that are dry and salty.
  • Add sauces or gravies to food to make them moister.


People going through cancer treatment can experience weight loss during times of decreased appetite or other treatment related side effects that affect the ability to eat. While a healthy diet is best, it is important to eat whatever works during this time to maintain your body weight and protein stores. In addition, your nutrition requirements may change over the course of your treatment. If you are finding it difficult to eat, are losing weight, or are unable to maintain a good diet, ask to meet with a dietitian who can help you manage these concerns.

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