Coping With Side Effects

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This document was provided by the National Institutes of Health/National Cancer Institute.

The following offers practical hints for coping with treatment side effects that may affect your eating.

These suggestions have helped other patients manage eating problems that can be frustrating to handle. Try all the ideas to find what works best for you. Share your needs and concerns with your family and friends, particularly those who prepare meals for you. Let them know that you appreciate their support as you work to take control of eating problems.

Loss of Appetite

Loss of appetite or poor appetite is one of the most common problems that occurs with cancer and its treatment. Many things affect appetite, including nausea, vomiting and being upset or depressed about having cancer. A person who has these feelings, whether physical or emotional, may not be interested in eating.

The following suggestions may help make mealtimes more relaxed so that you feel more like eating.

  • Stay calm, especially at mealtimes. Don't hurry your meals.
  • Involve yourself in as many normal activities as possible. If you feel uneasy and do not want to take part, don't force yourself.
  • Try changing the time, place, and surroundings of meals. A candlelight dinner can make mealtime more appealing. Set a colorful table. Listen to soft music while eating. Eat with others or watch your favorite TV program while you eat.
  • Eat whenever you are hungry. You do not need to eat just three main meals a day. Several small meals throughout the day may be even better.
  • Add variety to your menu. Try some of the recipes in the "Recipes for Better Nutrition During Cancer Treatment" section.
  • Eat food often during the day, even at bedtime. Have healthy snacks handy. Taking just a few bites of the right foods or sips of the right liquids every hour or so can help you get more protein and calories. You can find ideas for preparing snacks on Table 1.


Sore Mouth or Throat

Mouth sores, tender gums, and a sore throat or esophagus often result from radiation therapy, anti cancer drugs, and infection. If you have a sore mouth or gums, see your doctor to be sure the soreness is a treatment side effect and not an unrelated dental problem. The doctor may be able to give you medicine that will control mouth and throat pain. Your dentist also can give you tips for care of your mouth.

Certain foods will irritate an already tender mouth and make chewing and swallowing difficult. By carefully choosing the foods you eat and by taking good care of your mouth, you can usually make eating easier. Here are some suggestions that may help:

  • Try soft foods that are easy to chew and swallow, such as milkshakes; bananas, applesauce, and other soft fruits; peach, pear, and apricot nectars; watermelon; cottage cheese; mashed potatoes, macaroni and cheese; custards, puddings, and gelatin; scrambled eggs; oatmeal or other cooked cereals; pureed or mashed vegetables such as peas and carrots; pureed meats; liquids.
  • Avoid foods that can irritate your mouth: citrus fruit or juice such as oranges, grapefruits, tangerines; spicy or salty foods; rough, coarse, or dry foods such as raw vegetables, granola, toast, crackers.
  • Cook foods until they are soft and tender.
  • Cut foods into small pieces.
  • Mix food with butter, thin gravies, and sauces to make it easier to swallow.
  • Use a blender or food processor to puree your food.
  • Use a straw to drink liquids.
  • Try foods cold or at room temperature. Hot and warm foods can irritate a tender mouth and throat.
  • If swallowing is hard, tilting your head back or moving it forward may help.
  • If heartburn is a problem, try sitting up or standing for about an hour after eating.

  • If your teeth and gums are sore, your dentist may be able to recommend a special product for cleaning your teeth.
  • Rinse your mouth with water often to remove food and bacteria and to promote healing.
  • Ask your doctor about anesthetic lozenges and sprays that can numb the mouth and throat long enough for you to eat meals.

Changed Sense of Taste or Smell

Your sense of taste or smell may change during your illness or treatment. A condition called mouth blindness or taste blindness may give foods a bitter or metallic taste, especially meat or other high-protein foods. Many foods will have less taste. Chemotherapy, radiation therapy, or the cancer itself may cause these problems. Dental problems also can change the way foods taste. For most people, changes in taste and smell go away when their treatment is finished.

There is no "foolproof" way to improve the flavor or smell of food because each person is affected differently by illness and treatments. However, the tips given below should help make your food taste better. (If you also have a sore mouth, sore gums, or a sore throat, talk to your doctor or registered dietitian. They can suggest ways to improve the taste of your food without hurting the sore areas.)

  • Choose and prepare foods that look and smell good to you.
  • If red meat (such as beef) tastes or smells strange, use chicken, turkey, eggs, dairy products, or fish that doesn't have a strong smell instead.
  • Help the flavor of meat, chicken, or fish by marinating it in sweet fruit juices, sweet wine, Italian dressing, or sweet-and-sour sauce.
  • Try using small amounts of flavorful seasonings such as basil, oregano, or rosemary.
  • Try tart foods such as oranges or lemonade that may have more taste. A tart lemon custard might taste good and will also provide needed protein and calories. (Do not try this if you have a sore mouth or throat.)
  • Serve foods at room temperature.
  • Try using bacon, ham, or onion to add flavor to vegetables.
  • Stop eating foods that cause an unpleasant taste.
  • Visit your dentist to rule out dental problems that may affect the taste or smell of food.
  • Ask your dentist about special mouthwashes and good mouth care.

Dry Mouth

Chemotherapy and radiation therapy in the head or neck area can reduce the flow of saliva and often cause dry mouth. When this happens, foods are harder to chew and swallow. Dry mouth also can change the way foods taste. The suggestions below may be helpful in dealing with dry mouth. Also try some of the ideas for dealing with a sore mouth or throat, which can make foods easier to swallow.

  • Try very sweet or tart foods and beverages such as lemonade; these foods may help your mouth produce more saliva. (Do not try this if you also have a tender mouth or sore throat.)
  • Suck on sugar-free, hard candy or popsicles or chew sugar-free gum. These can help produce more saliva.
  • Use soft and pureed foods, which may be easier to swallow.
  • Keep your lips moist with lip salves.
  • Eat foods with sauces, gravies, and salad dressings to make them moist and easier to swallow.
  • Have a sip of water every few minutes to help you swallow and talk more easily.
  • If your dry mouth problem is severe, ask your doctor or dentist about products that coat and protect your mouth and throat.


Nausea, with or without vomiting, is a common side effect of surgery, chemotherapy, radiation therapy, and biological therapy. The disease itself, or other conditions unrelated to your cancer or treatment, also may cause nausea.

Whatever the cause, nausea can keep you from getting enough food and needed nutrients. Here are some ideas that may be helpful:

  • Ask your doctor about medicine to help control nausea and vomiting. These drugs are called antiemetics.
  • Try toast and crackers, yogurt, sherbet, pretzels, angel food cake, oatmeal, skinned chicken (baked or broiled, not fried), fruits and vegetables that are soft or bland (such as canned peaches), clear liquids (sipped slowly), and ice chips.
  • Avoid fatty, greasy, fried, spicy or hot food with strong odors; and sweets such as candy, cookies, or cake.
  • Eat small amounts often and slowly.
  • Avoid eating in a room that's stuffy, too warm, or has cooking odors that might disagree with you
  • Drink fewer liquids with meals. Drinking liquids can cause a full, bloated feeling.
  • Drink or sip liquids throughout the day, except at mealtimes. Using a straw may help.
  • Drink beverages cool or chilled. Try freezing favorite beverages in ice cube trays.
  • Eat foods at room temperature or cooler; hot foods may add to nausea.
  • Don't force yourself to eat favorite foods when you feel nauseated. This may cause a permanent dislike of those foods.
  • Rest after meals, because activity may slow digestion. It's best to rest sitting up for about an hour after meals.
  • If nausea is a problem in the morning, try eating dry toast or crackers before getting up.
  • Wear loose-fitting clothes.
  • Avoid eating for 1 to 2 hours before treatment if nausea occurs during radiation therapy or chemotherapy.
  • Try to keep track of when your nausea occurs and what causes it (specific foods, events, surroundings). If possible, make appropriate changes in your diet or schedule. Share the information with your doctor or nurse.


Vomiting may follow nausea and may be brought on by treatment, food odors, gas in the stomach or bowel, or motion. In some people, certain surroundings, such as the hospital, may cause vomiting.

If vomiting is severe or lasts for more than a few days, contact your doctor.

Very often, if you can control nausea, you can prevent vomiting. At times, though, you may not be able to prevent either nausea or vomiting. You may find some relief by using relaxation exercises or meditation. These usually involve deep rhythmic breathing and quiet concentration and can be done almost anywhere. If vomiting occurs, try these hints to prevent further episodes.

  • Ask your doctor about medicine to control nausea and vomiting (antiemetics).
  • Do not drink or eat until you have the vomiting under control.
  • Once you have controlled vomiting, try small amounts of clear liquids. (See Clear Liquid Diet) Begin with 1 teaspoonful every 10 minutes, gradually increase the amount to 1 tablespoonful every 20 minutes, and finally try 2 tablespoonfuls every 30 minutes.
  • When you are able to keep down clear liquids, try a full-liquid diet. (See Full Liquid Diet) Continue taking small amounts as often as you can keep them down. If you feel okay on a full-liquid diet, gradually work up to your regular diet. If you have a hard time digesting milk, you may want to try a soft diet instead of a full-liquid diet. When you feel okay on the soft diet, gradually add more foods to return to your regular diet. (You can find information about these and other diets under "Special Diets for Special Needs.")



Diarrhea may have several causes, including chemotherapy, radiation therapy to the abdomen, infection, food sensitivity, and emotional upset.

Long-term or severe diarrhea may cause other problems. During diarrhea, food passes quickly through the bowel before the body absorbs enough vitamins, minerals, and water. This may cause dehydration and increase the risk of infection. Contact your doctor if the diarrhea is severe or lasts for more than a couple of days. Here are some ideas for coping with diarrhea:

  • Drink plenty of liquids during the day. Drinking fluids is important because your body may not get enough water when you have diarrhea.
  • Eat small amounts of food throughout the day instead of three large meals.
  • Eat plenty of foods and liquids that contain sodium (salt) and potassium. These minerals are often lost during diarrhea. Good liquid choices include bouillon or fat-free broth. Foods high in potassium that don't cause diarrhea include bananas, peach and apricot nectar, and boiled or mashed potatoes.
  • Try these nutritious low-fiber foods: yogurt, rice or noodles, grape juice, farina or cream of wheat, eggs (cooked until the whites are solid, not fried), ripe bananas, smooth peanut butter, white bread, skinned chicken or turkey, lean beef, or fish (boiled or baked, not fried), cottage cheese, cream cheese.
  • Eliminate greasy, fatty, or fried foods, raw vegetables and fruits; high-fiber vegetables such as broccoli, corn, beans, cabbage, peas, and cauliflower; strong spices, such as hot pepper, curry, and Cajun spice mix.
  • Drink liquids that are at room temperature.
  • Avoid very hot or very cold foods and beverages.
  • Limit foods and beverages that contain caffeine, including coffee, strong tea, some sodas, and chocolate.
  • Be careful when using milk and milk products because diarrhea may be caused by lactose intolerance. (If you think you have this problem, see "Low-Lactose Diet.") Ask your doctor or registered dietitian for advice.
  • After sudden, short-term attacks of diarrhea (acute diarrhea), try a clear-liquid diet during the first 12 to 14 hours. This lets the bowel rest while replacing the important body fluids lost during diarrhea. (See Clear-Liquid Diet.)


Some anticancer drugs and other drugs, such as pain medicines, may cause constipation. This problem also may occur if your diet lacks enough fluid or bulk or if you have been bedridden.

Here are some suggestions to prevent and treat constipation:

  • Drink plenty of liquids -- at least eight 8-ounce glasses every day. This will help to keep your stools soft.
  • Take a hot drink about one-half hour before your usual time for a bowel movement.
  • Eat high-fiber foods, such as whole-grain breads, cereals, and pastas; fresh fruits and vegetables dried beans and peas; and whole-grain products such as barley or brown rice. Eat the skin on fruits and potatoes.
  • Get exercise, such as walking, every day. Talk to your doctor or a physical therapist about the amount and type of exercise that is right for you.
  • Add unprocessed wheat bran to foods such as cereals, casseroles, and homemade breads.
If these suggestions don't work, ask your doctor about medicine to ease constipation. Be sure to check with your doctor before taking any laxatives or stool softeners.

Weight Gain

Sometimes patients gain excess weight during treatment without eating extra calories. For example, certain anticancer drugs, such as prednisone, can cause the body to hold on to fluid, causing weight gain; this condition is known as edema. The extra weight is in the form of water and does not mean you are eating too much.

It is important not to go on a diet if you notice weight gain. Instead, tell your doctor so you can find out what may be causing this change. If anticancer drugs are causing your body to retain water, your doctor may ask you to speak with a registered dietitian. The registered dietitian can teach you how to limit the amount of salt you eat, which is important because salt causes your body to hold extra water. Drugs called diuretics also may be prescribed to get rid of extra fluid.

Tooth Decay

Cancer and cancer treatment can cause tooth decay and other problems for your teeth and gums. Changes in eating habits also may add to the problem. If you eat frequently or consume a lot of sweets, you may need to brush your teeth more often. Brushing after each meal or snack is a good idea.

Here are some ideas for preventing dental problems:

  • Be sure to see your dentist regularly. Patients who are receiving treatment that affects the mouth (e.g., radiation to the head and neck) may need to see the dentist more often than usual.
  • Use a soft toothbrush. Ask your doctor. nurse, or dentist to suggest a special kind of toothbrush and/or toothpaste if your gums are very sensitive.
  • Rinse your mouth with warm water when your gums and mouth are sore.
  • If you are not having trouble with poor appetite or weight loss, limit the amount of sugar in your diet.
  • Avoid eating foods that stick to the teeth, such as caramels or chewy candy bars.
Lactose Intolerance

Lactose intolerance means that your body can't digest or absorb the milk sugar called lactose. Milk, other dairy products, and foods to which milk has been added contain lactose.

Lactose intolerance may occur after treatment with some antibiotics, radiation to the stomach, or any treatment that affects the digestive tract. The part of your intestines that breaks down lactose may not work properly during treatment. For some people, symptoms of lactose intolerance (gas, cramping, diarrhea) disappear a few weeks or months after the treatments end or when the intestine heals. For others a permanent change in eating habits may be needed.

If you have this problem, your doctor may advise you to follow a diet that is low in foods that contain lactose. (See "Low-Lactose Diet.") If milk had been a main source of protein in your diet, it will be important to get enough protein from other foods. Products such as soybean and aged cheeses are good sources of protein and other nutrients. You also may want to try low-lactose milk or liquid drops or caplets that help break down the lactose in milk and other dairy products. The recipe section of this guide can give you ideas for preparing low lactose dishes.


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