Going through cancer treatment can be overwhelming, especially when side effects start to affect your appetite, eating habits, or ability to enjoy food.
Nutrition can play an important role in helping you maintain your strength and support your body during treatment. But eating well is not always easy when symptoms like nausea, taste changes, dry mouth, or digestive issues get in the way. Even small changes in what, when, or how you eat can sometimes make meals feel more manageable.
Everyone’s experience with treatment is different. Some people may notice changes in taste, dry mouth, mouth sores, nausea, diarrhea, or constipation, while others may experience different challenges. The type of cancer, treatment you receive, and other individual factors can all influence how your body responds.
In this blog, we’ll walk through practical strategies that may help make eating and drinking a little easier during treatment. These tips are meant to offer general support, but your needs may be different, so it’s always important to follow the guidance of your cancer care team.
Before we get into specific symptoms, it can help to remember that there is no single “right” way to eat during cancer treatment. What works well one day may not work the next, and different side effects may call for different approaches. The goal is to find foods, fluids, and routines that help you stay as nourished and comfortable as possible while following the guidance of your care team.
Managing Taste Changes
Cancer treatment can change the way foods taste or smell. Foods you normally enjoy may suddenly taste metallic, bitter, overly sweet, bland, or simply “off.” These changes can make eating less enjoyable and, for some people, make it harder to eat enough during treatment.
The good news is that a little trial and error can help. What tastes good may change from day to day, so focus on finding flavors, temperatures, and foods that work for you.
A few things you can try:
- Switch up your utensils. If food has a metallic taste, try using plastic utensils instead of metal ones.
- Experiment with seasonings. Herbs, spices, marinades, or other stronger flavors may make foods more appealing. If you also have mouth sores or pain with swallowing, avoid seasonings or acidic ingredients that irritate your mouth or throat.
- Try different foods and flavors. Taste changes are highly individual, so foods that no longer appeal to you may be easier to replace temporarily with other foods that provide similar nutrients. Staying flexible can help as your preferences change during treatment.
- Keep your mouth clean and comfortable. Good mouth care can be helpful when treatment affects taste or causes other mouth-related side effects. Follow any specific mouth-care recommendations from your cancer care team.
Remember: You do not have to force yourself to eat a food just because it used to be a favorite. Give yourself room to experiment with foods and flavors that work better for you right now. If taste changes are making it difficult to eat enough or are contributing to unintended weight loss, talk with your cancer care team or dietitian.
Dry Mouth (Xerostomia)
Dry mouth, also called xerostomia, can happen when cancer treatment reduces the amount of saliva your mouth makes or changes its consistency. Without enough saliva, chewing, swallowing, and even talking can become uncomfortable. Dry mouth can also increase the risk of cavities and other oral health problems, so keeping your mouth comfortable and clean is especially important.
A few things you can try:
- Sip fluids throughout the day. Taking frequent sips of water can help keep your mouth moist and may make chewing and swallowing easier.
- Add moisture to your meals. Gravies, sauces, broths, dressings, and other moist foods can make dry foods easier to eat and swallow.
- Choose foods that feel comfortable. Very dry, rough, salty, spicy, or acidic foods may irritate a dry or sensitive mouth. Pay attention to what feels comfortable for you, especially if you also have mouth sores.
- Keep up with gentle mouth care. Good oral hygiene is particularly important when your mouth is dry. Follow the mouth-care routine recommended by your cancer care team, including any instructions about brushing or rinsing.
- Protect dry lips. A lip moisturizer or balm can help keep dry or cracked lips more comfortable.
- Ask about saliva substitutes. If sipping fluids and adjusting foods are not enough, your care team may recommend a saliva substitute or another product designed to relieve dry mouth.
If dry mouth is making it difficult to eat, drink, or swallow, or if you notice new mouth pain, sores, or dental problems, let your cancer care team know. They can help determine whether additional treatment or oral-care support may be helpful.
Mouth Sores and Throat Pain
Some cancer treatments can cause soreness, inflammation, or ulcers in the mouth and throat. This may be called oral mucositis when it affects the mouth, and esophagitis when inflammation affects the esophagus. These symptoms can make chewing, swallowing, and drinking uncomfortable, so the goal is to choose foods and drinks that are gentle and easier to tolerate.
A few things you can try:
- Choose soft, moist foods. Foods that are easy to chew and swallow may be more comfortable when your mouth or throat is sore. Adding sauces, gravies, broth, or other moisture can also make foods easier to eat.
- Experiment with food temperature. Cool or room-temperature foods may feel more comfortable for some people. Avoid foods or drinks that are very hot if they irritate sensitive areas, and choose the temperature that feels best for you.
- Avoid foods that sting or scrape. Acidic foods such as citrus and tomatoes, as well as spicy, salty, rough, or crunchy foods like chips, may irritate mouth sores and make eating more uncomfortable.
- Keep your mouth clean with gentle rinses. Your cancer care team may recommend a saltwater, baking soda, or combination rinse to help keep your mouth clean and comfortable. Follow their instructions about which rinse to use and how often.
- Avoid mouthwashes that may irritate your mouth. Some commercial mouthwashes contain alcohol or other ingredients that can sting or dry irritated tissue. Ask your care team which oral-care products are best for you during treatment.
Because mouth or throat soreness can make it harder to get enough food and fluids, let your care team know if the pain is getting worse, you are having trouble swallowing, or sores are interfering with your ability to eat or drink. Mouth sores can also become infected, so addressing changes early is important.
Nausea
Nausea is a common side effect of cancer treatment, and it can make eating feel difficult even when you know your body needs nourishment. Some people find that smaller meals, milder foods, and fewer strong smells make eating more manageable.
A few things you can try:
- Eat small, frequent meals. Instead of three large meals, try eating smaller meals or snacks throughout the day. For some people, an empty stomach can make nausea feel worse.
- Try cold or room-temperature foods. Hot foods can have stronger aromas, which may be harder to tolerate when you feel nauseated. Cold or room-temperature foods may be easier to manage.
- Sip fluids between meals. If drinking a lot with meals makes you feel overly full or uncomfortable, try taking small sips during meals and getting most of your fluids between meals. Staying hydrated is especially important if you are vomiting.
- Choose foods that are easier on your stomach. Fried, greasy, or very rich foods may be harder to tolerate when you are nauseated. Bland or easy-to-digest foods may feel better, depending on what works for you.
- Ginger may be worth trying. Some people find ginger-containing foods or drinks helpful when they feel nauseated, although research on ginger for cancer-treatment nausea has shown mixed results. Check with your care team before using concentrated ginger products or supplements.
- Stay upright after eating. Sitting upright after meals instead of lying down right away may help you feel more comfortable.
Diarrhea
Diarrhea can happen during cancer treatment and may lead to dehydration if you lose more fluid than you are able to replace. When this happens, the focus is usually on staying hydrated and choosing foods that are easier on your digestive system until symptoms improve.
A few things you can try:
- Eat smaller meals more often. Smaller meals or snacks throughout the day may be easier to tolerate than three large meals.
- Choose lower-fiber foods for a short time. Your doctor or dietitian may recommend temporarily limiting fiber when you have diarrhea. Foods such as white rice, bananas, applesauce, refined breads, or other easy-to-digest foods may be easier to tolerate.
- Stay on top of fluids. Diarrhea causes your body to lose fluids and electrolytes, so replacing them is important. Water, broth, and other clear liquids may help, but ask your care team how much fluid is right for you.
- Limit foods and drinks that may make symptoms worse. Greasy or high-fat foods, caffeine, and alcohol may worsen diarrhea or contribute to fluid loss. Your tolerance may vary, so pay attention to what seems to trigger symptoms for you.
- Pay attention to dairy. Some people have more difficulty tolerating lactose when they have treatment-related diarrhea. If milk or other dairy products seem to make symptoms worse, ask your care team or dietitian whether lactose-free alternatives might be helpful.
Diarrhea during cancer treatment may need more than dietary changes, especially if it continues or becomes severe. Let your care team know if you are having ongoing diarrhea or are having trouble staying hydrated so they can determine the cause and whether medication or other treatment is needed.
Constipation
Constipation can be uncomfortable, and it is common during cancer treatment. Certain medications—including some pain medicines, chemotherapy drugs, and anti-nausea medicines—can contribute, along with lower activity levels, not drinking enough fluids, or changes in what you are eating.
A few things you can try:
- Stay hydrated. Drinking enough fluids can help prevent and manage constipation. Your fluid needs may be different depending on your treatment or other health conditions, so follow any guidance your care team has given you.
- Add fiber carefully. If your care team recommends increasing fiber, add it gradually through foods such as fruits, vegetables, whole grains, and beans, and make sure you are drinking enough fluids.
- Move when you can. Regular physical activity can help prevent and manage constipation. Even gentle movement may be helpful, depending on how you are feeling and what your care team says is safe for you.
- Talk with your care team before using medications. Stool softeners, laxatives, and other treatments may be needed, especially when constipation is related to medications. Your care team can help you choose an appropriate option rather than trying one on your own.
Constipation can have several causes during cancer treatment, so dietary changes may not always be enough. Let your cancer care team know if constipation continues, becomes painful, or is noticeably different from your usual bowel habits so they can help determine what may be contributing and recommend the right approach.
Finding What Works for You
Nutrition can be an important part of managing side effects during cancer treatment. Small adjustments to foods, fluids, meal timing, and textures may help make eating and drinking more manageable when symptoms get in the way. Because everyone responds to treatment differently, finding the right approach may take some trial and error and should reflect both what works for you and the guidance of your care team.
If side effects are making it harder to eat, drink, maintain your weight, or meet your nutrition needs, you do not have to figure it out on your own. Our providers are here to support you, answer questions, and help you find practical strategies that fit your treatment and symptoms. Reach out to your care team for personalized guidance and additional support when you need it.
Resources:
- American Cancer Society. Drinking and Eating Changes. American Cancer Society.
- American Cancer Society. Mouth Dryness or Thick Saliva. American Cancer Society.
- American Cancer Society. Mouth Sores and Pain. American Cancer Society.
- American Cancer Society. Taste and Smell Changes. American Cancer Society.
- Memorial Sloan Kettering Cancer Center. Eating Well During Your Cancer Treatment. Memorial Sloan Kettering Cancer Center.
- National Cancer Institute. Diarrhea and Cancer: Side Effects. National Institutes of Health.
- National Cancer Institute. Mouth and Throat Problems: Cancer Treatment Side Effects. National Institutes of Health.
- National Cancer Institute. Nutrition During Cancer. National Institutes of Health.
- Width, M., & Reinhard, T. The Essential Pocket Guide for Clinical Nutrition. 3rd ed. Jones & Bartlett Learning; 2020.