Senior Living | Care Listings | Guidance | Experts 


Effects of Advanced  Cancer TreatmentDuring cancer treatment, some cancer patients may experience side effects that may cause eating problems. Sometimes it is the side effects of treatment such as nausea, vomiting, or changes in food’s taste or smell that makes cancer patients feel like not eating.

To ensure proper nutrition during cancer treatment, be sure to work with your doctor or nurse to get the side effects under better control. They will help you answer questions and concerns you may have to help you with proper nutrition during cancer treatment. This article will also provide some suggestions to help cope with the side effects from cancer treatments.

In This Article:

Loss of Appetite
Weight Loss
Weight Gain
Sore Mouth or Throat
Dry Mouth
Dental and Gum Problems
Changed Sense of Taste or Smell
Lactose Intolerance
Fatigue and Depression

Preventing Food-Borne Illness

Loss of Appetite

Loss of appetite or poor appetite is one of the most common problems that occurs with cancer and its treatment. No one knows exactly what causes loss of appetite. It may be caused by the treatments or by the cancer itself. Emotions such as fear or depression can also take away a person’s appetite. Ask a nurse or social worker about ways to lessen these emotional difficulties.

For some people, loss of appetite happens for just a day or two; for others, it’s an ongoing concern.

Here are some suggestions that might help:

  • Try liquid or powdered meal replacements, such as "instant breakfast," during times when it is hard for you to eat food.
  • Try frequent small meals throughout the day, rather than fewer big ones. It may be easier to eat more that way, and you won’t get so full.
  • Keep snacks within easy reach so you can have something whenever you feel like it. Cheese and crackers, muffins, ice cream, peanut butter, fruit, and pudding are good possibilities. Take a portable snack with you when you go out, such as peanut butter crackers or small boxes of raisins
  • Even if you don’t feel like eating solid foods, try to drink beverages during the day. Juice, soup, and other fluids like them can give you important calories and nutrients. Milk-based drinks also provide protein
  • If possible, try having something at bedtime. It won’t affect your appetite for the next meal.
  • Sometimes, changing the form of a food will make it more appetizing and help you eat better. For example, if eating whole, fresh fruit is a problem, try mixing fruit into a milkshake.
  • Try softer, cool, or frozen foods, such as yogurt, milkshakes, or popsicles.
  • Take advantage of times when you do feel well, and have a larger meal then. Many people have a better appetite first thing in the morning, when they are well rested.
  • During meals, sip only small amounts because drinking may make you feel full. If you want to have more than just a small amount to drink, have it 30-60 minutes before or after a meal.
  • Make mealtimes as relaxed and pleasant as possible. Presenting food or meals in an attractive way may also help.
  • If your doctor allows, have a small glass of wine or beer during a meal. It may help to stimulate your appetite.
  • Regular exercise may help your appetite. Check with your doctor to see what options are open to you.

Weight Loss

Many cancer patients lose weight during their cancer treatment. This is partly due to the effects of the cancer itself on the body. Also, if you’ve lost your appetite and are eating less than usual because of your treatment or emotional worries, you may lose weight. The tips under Loss of Appetite may help, too.

For extra protein in dishes, consider adding a little nonfat instant dry milk to scrambled eggs, soup, cereal, sauces, and gravies.

Weight Gain

Some patients find their weight does not change during treatment. They may even gain weight. This is particularly true for breast cancer, prostate cancer, and ovarian cancer patients taking certain medications or who are on hormone therapy or chemotherapy.

It is important not to go on a diet right away if you notice weight gain during your cancer treatment. Instead, tell your doctor so you can find out what may be causing this change. Sometimes, weight gain happens because certain anticancer drugs can cause your body to hold on to excess fluid. This condition is called edema. The weight comes from the extra water. If this is the case, your doctor may ask you to talk with a registered dietitian for guidelines on limiting the amount of salt you eat. This is important because salt causes your body to hold extra water. Your doctor may also want to prescribe a diuretic. This is a medication that causes your body to get rid of excess fluid.

Breast cancer patients with a primary diagnosis of cancer may be different. Over half of them may actually gain weight rather than lose during treatment. Because of this, many of the recommendations for breast cancer patients do emphasize a lower fat, reduced calorie diet similar to those provided to patients after cancer treatment has been completed.

Weight gain may also be the result of increased appetite and eating extra food and calories. If this is the case and you want to stop gaining weight, talk to a registered dietitian for more guidance.

Here are some tips:

  • Eat more fruits, vegetables, and breads and cereals.
  • Choose lean meats (lean beef or pork trimmed of fat, chicken without skin) and low-fat dairy products (skim or 1% milk, light yogurt).
  • Cut back on added butter, mayonnaise, sweets, and other extras.
  • Choose low-fat and low-calorie cooking methods (broiling, steaming).
  • Avoid eating high-calorie snacks between meals.
  • If you feel up to it, increase the amount of exercise you get.
Sore Mouth or Throat

Mouth sores, tender gums, and a sore throat or esophagus often result from radiation therapy, chemotherapy, or 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 the 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, teeth, and gums, you can usually make eating easier.

Here are some suggestions that may help:

  • Avoid foods or liquids that can irritate your mouth. These include: oranges, grapefruits, lemons, or other citrus fruit or juice, tomato sauces or juice, spicy or salty foods, raw vegetables, granola, toast, crackers, or other rough, coarse, or dry foods, commercial mouthwashes that contain alcohol
  • Cook foods until they are soft and tender.
  • Cut foods into small pieces.
  • Use a blender or food processor to puree your food.
  • Mix food with butter, margarine, thin gravy, or sauce to make it easier to swallow.
  • Use a straw to drink liquids.
  • Use a smaller-than-usual spoon, such as a baby spoon.
  • Try foods cold or at room temperature. Hot foods can irritate a tender mouth and throat.
  • Try drinking warm bouillon or salty broth; it can soothe throat pain.
  • Try sucking on ice chips.
  • If swallowing is hard, tilting your head back or moving it forward may help.
  • If your teeth and gums are sore, your dentist may be able to recommend a special product for cleaning your teeth.
  • Rinse your mouth often with water to remove food and bacteria and to promote healing.
  • Ask your doctor about anesthetic lozenges and sprays that can numb your mouth and throat long enough for you to eat meals.
Dry Mouth

Chemotherapy and radiation therapy in the head or neck area can reduce the flow of saliva and cause dry mouth. When this happens, foods are harder to chew and swallow. Dry mouth also can change the way foods taste. Some of the ideas for sore mouth and throat may help.

The suggestions below also may help you deal with dry mouth.

  • Have a sip of water every few minutes to help you swallow and talk more easily. Consider carrying a water bottle with you so you always have some handy.
  • Try very sweet or tart foods and beverages, such as lemonade; these foods may help your mouth make more saliva. (Do not try this if you also have a tender mouth or sore throat and the sweet or tart foods make it worse.)
  • Suck on hard candy or popsicles or chew gum. These can help make more saliva.
  • Eat soft and pureed foods, which may be easier to swallow.
  • Keep your lips moist with lip salves.
  • Moisten food with sauces, gravies, and salad dressings to make it easier to swallow.

If your dry mouth problem is severe, ask your doctor or dentist about products that coat, protect, and moisten your mouth and throat. These are sometimes called "artificial saliva."

Dental and Gum Problems

Cancer and cancer treatment can cause tooth decay and other problems for your teeth and gums. For example, radiation to the mouth can affect your salivary glands, making your mouth dry and increasing your risk of cavities. Changes in eating habits also may add to the problem. Your doctor and dentist should work closely together to fix any problems with your teeth before you start treatment. If you eat often or eat 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 other ideas for preventing dental problems:

  • Be sure to let your doctor know about any dental problems you are having.
  • Be sure to see your dentist regularly. Patients who are receiving treatment that affects the mouth – for example, 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 eating foods high in sugar or foods that stick to your teeth, be sure to brush or rinse your mouth afterward so that the sugar won’t damage your teeth, or use sugar-free varieties. (Sorbitol, a sugar substitute that is contained in many sugar-free foods, can cause diarrhea in many people. If diarrhea is a problem for you, check the labels of sugar-free foods before you buy them and limit your use of them.)

Changed Sense of Taste or Smell

Your sense of taste or smell may change during your illness or treatment. Foods, especially meat or other high-protein foods, can begin to have a bitter or metallic taste. 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 prevent changes to your sense of taste or smell because each person is affected differently by illness and treatments. If you also have a sore mouth, sore gums, or a sore throat, talk to your doctor, nurse, or registered dietitian. They can suggest ways to help you without hurting the sore areas.

Here are some to help solve this problem:

  • Choose and prepare foods that look and smell good to you.
  • If red meat, such as beef, tastes or smells strange, try chicken, turkey, eggs, dairy products, or mild-tasting fish 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. (If you have a sore mouth or throat, tart or citrus foods might cause pain or discomfort.)
  • If smells bother you, try serving foods at room temperature, turning on a kitchen fan, covering foods when cooking, and cooking outdoors in good weather.
  • Try using bacon, ham, or onion to add flavor to vegetables.
  • Visit your dentist to rule out dental problems that may affect the taste or smell of food.
  • Ask your dentist or doctor about special mouthwashes and good mouth care.


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, may also cause nausea. Some people have nausea or vomiting right after treatment; others don’t have it until two or three days after a treatment. Many people never experience nausea. For those who do, nausea often goes away once the treatment is completed. Also, there are now drugs that can effectively control this side effect. These medications, called antiemetics, are often given at the beginning of a chemo-therapy session to prevent nausea. Whatever the cause, nausea can keep you from getting enough food and needed nutrients.

Here are some ideas that can help:

  • Ask your doctor about antiemetics that might help you control nausea and vomiting.
  • Try foods that are easy on your stomach, such as:
    • toast, crackers, and pretzels
    • yogurt
    • sherbet
    • angel food cake
    • cream of wheat, rice, or oatmeal
    • boiled potatoes, rice, or noodles
    • skinned chicken that is baked or broiled, not fried
    • canned peaches or other soft, bland fruits and vegetables
    • o clear liquids
    • ice chips
    • carbonated drinks
  • Avoid foods that:
    • are fatty, greasy, or fried
    • are very sweet, such as candy, cookies, or cake
    • are spicy or hot
    • have strong odors
  • Eat small amounts, often and slowly. Eat before you get hungry, because hunger can make feelings of nausea stronger.
  • If nausea makes certain foods unappealing, then eat more of the foods you find easier to handle.
  • 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.
  • Slowly drink or sip liquids throughout the day. A straw may help.
  • Have foods and drinks 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 for 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.
  • If nausea occurs during radiation therapy or chemotherapy, avoid eating for 1 to 2 hours before treatment.
  • Try to keep track of when your nausea occurs and what causes it. If possible and if it helps, change 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 associations or surroundings, such as the hospital, may cause vomiting. As with nausea, some people have vomiting right after treatment, while others don’t have it until a day or more after treatment.

If vomiting is severe or lasts for more than a day or two, contact your doctor. He or she may give you an antiemetic medication to control nausea and vomiting.

Very often, if you can control nausea, you can prevent vomiting. At times, though, you may not be able to prevent either. Relaxation exercises or meditation may help you. These usually involve deep rhythmic breathing and quiet concentration, and can be done almost anywhere.

If vomiting does occur, try these suggestions to help prevent further episodes:

  • Do not eat or drink anything until you have the vomiting under control.
  • Once the vomiting is under control, try small amounts of clear liquids, such as water or bouillon. Begin with 1 teaspoonful every 10 minutes, gradually increasing the amount to 1 tablespoon every 20 minutes. Finally, try 2 tablespoons every 30 minutes.
  • When you are able to keep down clear liquids, try a full-liquid diet or a soft diet. Continue taking small amounts as often as you can keep them down. If you feel okay, 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, because a full-liquid diet includes a lot of milk products. Ask a registered dietitian for information about a soft diet.


Diarrhea may have several causes, including chemotherapy, radiation therapy to the abdomen, infection, food sensitivities, and emotional upset. Work with your doctor to identify the cause of your diarrhea so that it can be successfully treated.

During diarrhea, food passes quickly through the bowel before your body has a chance to absorb enough vitamins, minerals, and water. This may cause dehydration, which means that your body does not have enough water to work well. Long-term or severe diarrhea may cause problems, so 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 fluids to replenish what you lose with the diarrhea.
  • Eat small amounts of food throughout the day instead of three large meals.
  • Eat plenty of foods and liquids that contain sodium and potassium, two important minerals that help your body work properly. These minerals are often lost during diarrhea. Good high-sodium liquids 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. Sports drinks contain both sodium and potassium and have easily absorbable forms of carbohydrates.
  • Avoid the following:
    • greasy, fatty, or fried foods if they make your diarrhea worse
    • raw vegetables and the skins, seeds, and stringy fibers of unpeeled fruits
    • high-fiber vegetables, such as broccoli, corn, dried beans, cabbage, peas, and cauliflower
  • Avoid very hot or cold food or beverages. Drink liquids that are at room temperature.
  • Limit foods and drinks that contain caffeine, such as coffee, some sodas, and chocolate.
  • If you have a sudden, short-term attack of diarrhea, try having nothing but clear liquids for the next 12 to 14 hours. This lets your bowel rest and replaces the important fluids lost during the diarrhea. Make sure your doctor or nurse knows about this problem.
  • Be careful when using milk and milk products. The lactose they contain can make diarrhea worse. Most people, though, can handle small amounts (about 1-1/2 cups) of milk or milk products.

Lactose Intolerance

Lactose intolerance means that your body can’t digest or absorb the milk sugar called lactose. Milk, other milk-based dairy products (such as cheese and ice cream), and foods to which milk has been added (such as pudding) may contain lactose.

Lactose intolerance may occur after treatment with some antibiotics, with radiation to the stomach or with any treatment that affects the digestive tract. The part of your intestines that digests lactose may not work properly during treatment. For some people, the symptoms of lactose intolerance (gas, cramps, 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. Talk to a registered dietitian to get advice and specific tips about how to follow a low-lactose diet. Your supermarket should carry milk and other products that have been modified to reduce or eliminate the lactose.


Some anticancer drugs and other drugs, such as pain medications, may cause constipation. This problem also can occur if your diet lacks enough fluid or fiber, or if you’ve been in bed for a long time.

Here are some suggestions for preventing and treating constipation:

  • Drink plenty of liquids – at least eight 8-ounce glasses every day. This will help to keep your stools soft. Another way to think about fluids is to try to drink at least 1/2 oz. per pound of your body weight.
  • Have a hot drink about one-half hour before your usual time for a bowel movement.
  • Check with your doctor to see if you can increase the fiber in your diet (there are certain types of cancer for which a high-fiber diet is not recommended). If you can, try foods such as whole-grain breads and cereals, dried fruits, wheat bran, wheat germ; fresh fruits and vegetables; dried beans and peas. Eat the skin on potatoes. Make sure you also drink plenty of fluids to help the fiber work.
  • Get some exercise every day. Talk to your doctors or a physical therapist about the amount and type of exercise that’s right for you.

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.

Fatigue and Depression

All the methods of treating cancer treatment are powerful. Treatment may go on for weeks or months. It may even cause more illness or discomfort than the initial disease. Many patients say they feel exhausted and depressed, and unable to concentrate. Fatigue during cancer treatment can be related to a number of causes: not eating, inactivity, low blood counts, depression, poor sleep, and side effects of medicine. It is important for you to raise the issue with your health care team if you are having fatigue. Together, you can decide what is causing the problem, since many of the causes can be treated.

Fatigue and depression aren’t eating problems in and of themselves, but they can affect your interest in food and your ability to shop and prepare healthy meals.

Here are some suggestions that may help:

  • Talk about your feelings and your fears. Being open about your emotions can make them seem more manageable. Consider talking with your nurse or social worker, who can help you find ways to lessen your worries and fears.
  • Become familiar with your treatment, possible side effects, and ways of coping. Being knowledgeable and acting on that knowledge will help you feel more in control. Don’t be afraid to talk with your doctor and ask questions.
  • Make sure you get enough rest:
  • Take several naps or rest breaks during the day, rather than one long rest
  • Plan your day to include rest breaks
  • Make rest time special with a good book in a comfortable chair or a favorite video with a friend
  • Try easier or shorter versions of your usual activities; don’t push yourself to do more than you can manage.
  • Save your favorite foods for times that aren’t associated with treatment sessions. That way, they won’t be linked to an uncomfortable or distressing event.
  • Take short walks or get regular exercise, if possible. Some people find this helps to lessen their fatigue and raise their spirits.

Preventing Food-Borne Illness

Cancer patients undergoing treatment can develop a weakened immune system because most anticancer drugs decrease the body’s ability to make white blood cells, the cells that fight infection. That’s why cancer patients should be especially careful to avoid infections and food-borne illnesses.

Here are some tips to help you prevent food-borne illness:

  • Wash all raw fruits and vegetables well. If it can’t be well washed (as with raspberries), avoid it. Scrub rough surfaces, like the skin of melons, prior to cutting.
  • Carefully wash your hands and food preparation surfaces (knives, cutting boards) before and after preparing food, especially after handling raw meat.
  • Thaw meat in the refrigerator, not on the kitchen counter.
  • Be sure to cook meat and eggs thoroughly.
  • Avoid raw shellfish and use only pasteurized or processed ciders and juices and pasteurized milk and cheese.

Nutrition Recommendations For Cancer Patients to get tips on how cancer patients can feel better and stronger during cancer treatment.

Related Articles:

Eating Problems During Cancer Treatment
Nutrition in Cancer Care

Other La Dolce Living Helpful Links:

Follow Us:
0 votes, average: 0.00 out of 50 votes, average: 0.00 out of 50 votes, average: 0.00 out of 50 votes, average: 0.00 out of 50 votes, average: 0.00 out of 5 (0 votes, average: 0.00 out of 5)
You need to be a registered member to rate this post.