Skip to main content
  • Patient Portal
  • Pay Bill
  • Request Appointment
MCHS_Logo_2024_BLACK
    • Cardiology (Heart)
    • Gastroenterology & Hepatology (Digestive Care)
    • Neurosurgery
    • Obstetrics & Gynecology (OB-GYN)
    • Oncology (Cancer)
    • Orthopedics & Orthopedic Surgery (Bones)
    • Primary Care
    • Spine Care
    • Sports Medicine
    • Urology
    View all specialties
  • Providers
  • Minnesota

    • Albert Lea
    • Austin
    • Blooming Prairie
    • Butterfield
    • Cannon Falls
    • Fairmont
    • Faribault
    • Lake City
    • Mankato
    • New Prague
    • Northfield
    • Owatonna
    • Plainview
    • Red Wing
    • Sherburn
    • St. James
    • Waseca
    • Zumbrota

    Wisconsin

    • Arcadia
    • Barron
    • Bloomer
    • Chetek
    • Chippewa Falls
    • Eau Claire
    • Ellsworth
    • Glenwood City
    • Holmen
    • La Crosse
    • Menomonie
    • Mondovi
    • Onalaska
    • Osseo
    • Prairie du Chien
    • Rice Lake
    • Sparta
    • Tomah
    mchsmap Map view
    • VirtualCare
      Virtual Care
    • SameDayCare
      Same-Day Care
    • PrimaryCare
      Primary Care
    • SpecialtyCare
      Specialty Care
    • View all care options
    • PrimaryCare
      Billing & Insurance
    • SameDayCare
      Financial Assistance
    • VirtualCare
      Price Transparency
  • Health & Wellness Resources
    • Patient Portal
    • Pay Bill
    • Request Appointment
    MCHS_Logo_2024_BLACK
        • Cardiology (Heart)
        • Gastroenterology & Hepatology (Digestive Care)
        • Neurosurgery
        • Obstetrics & Gynecology (OB-GYN)
        • Oncology (Cancer)
        • Orthopedics & Orthopedic Surgery (Bones)
        • Primary Care
        • Spine Care
        • Sports Medicine
        • Urology
        • View all specialties
      • Providers
        • Minnesota

        • Albert Lea
        • Austin
        • Blooming Prairie
        • Butterfield
        • Cannon Falls
        • Fairmont
        • Faribault
        • Lake City
        • Mankato
        • New Prague
        • Northfield
        • Owatonna
        • Plainview
        • Red Wing
        • Sherburn
        • St. James
        • Waseca
        • Zumbrota

          Wisconsin

        • Arcadia
        • Barron
        • Bloomer
        • Chetek
        • Chippewa Falls
        • Eau Claire
        • Ellsworth
        • Glenwood City
        • Holmen
        • La Crosse
        • Menomonie
        • Mondovi
        • Onalaska
        • Osseo
        • Prairie du Chien
        • Rice Lake
        • Sparta
        • Tomah
        • Map view
        • Virtual Care
        • Same-Day Care
        • Primary Care
        • Specialty Care
        • View all care options
        • Billing & Insurance
        • Financial Assistance
        • Price Transparency
      • Health & Wellness Resources

      Recent Posts

      • TreatingNewbornJaundice_Blog_660x370
        Speaking of Health
        Newborn jaundice and light therapy
        December 09, 2025
      • Don H patient blog image
        Patient Stories
        A lifesaver saved: An EMS veteran’s journey from rescue to recovery
        November 14, 2025
      • Child eating apple
        Speaking of Health
        How to help your child reach a healthy weight
        October 29, 2025
      Featured Topics
      • Behavioral Health
      • Cancer
      • Children's Health (Pediatrics)
      • Exercise and Fitness
      • Heart Health
      • Men's Health
      • Neurosurgery
      • Obstetrics and Gynecology
      • Orthopedic Health
      • Weight-loss (Bariatric) Surgery
      • Women's Health
      Speaking of Health
      Wednesday, March 30, 2022

      Diet tips during cancer treatment

      Topics in this Post
      • Nutrition
      • Cancer
      Person wearing head scarf, holding coffee cup while outdoors

      The foods we eat act as fuel for our bodies. They give strength and stamina to power through the day. At no time is this more important than when a person is undergoing treatment for cancer.

      While lifesaving or life-preserving, chemotherapy and radiation treatments can take a toll on a person's body and significantly affect their diet.

      For example, chemotherapy not only kills rapidly dividing cancer cells, but also it can destroy fast-growing healthy cells. This may cause nausea or appetite changes, leading patients to consume fewer calories than needed. Other treatments can cause uncomfortable dry mouth, diarrhea or constipation. Fortunately, these side effects can be overcome and thereby improve nutrition during treatment.

      Weight changes

      One of the things patients and caregivers ask about is weight changes during treatment. Generally, if a patient loses more than 3 pounds in one week, it's important to discover if the loss was intentional or unintentional. If it's intentional, the patient's care team will discuss why this is occurring and make sure treatment plans are going well.

      If the weight loss is unintentional, it's important to seek out the cause and provide support. It's important to avoid a rapid decline in weight because muscle tissue is being broken down during treatment. This can lead to further loss of the patient's stamina.

      Poor appetite

      The cause of weight loss that patients report most frequently is poor appetite. This is a common side effect during cancer treatment.

      To improve nutrition during this time, it helps to plan for small, frequent meals. That can be daunting because patients and caregivers may not have the energy to make multiple meals each day.

      One way to get around this is to reserve a portion of what would have been normally eaten during breakfast, lunch and dinner for a fourth small meal. This makes it easier to plan and schedule additional meals with less work.

      Here are other ways that caregivers can help a loved one who is experiencing weight loss due to poor appetite:
      • Gently remind the loved one to eat small, frequent meals and snacks throughout the day.
      • Offer starchy foods and high-protein foods together. For example, a piece of toast and cheese stick.
      • Keep cool drinks and juices within reach. Drinking between meals keeps the person hydrated while avoiding filling up on liquids during mealtimes.
      • Create pleasant settings for meals and eat together. Light a candle or place the table near a window to enjoy the view.
      • Choose high-calorie foods or nutrition supplement drinks.

      Nausea

      Damage to the stomach and intestinal lining during cancer treatment can cause nausea and vomiting. Many medications are available that control nausea and provide relief.

      Patients and caregivers also can do other things to ease this side effect through diet, including:
      • Choose easily digestible foods, such as refined carbohydrates like white bread and potatoes. Avoid high-fiber, high protein foods, as these foods take longer to digest.
      • Eat small, frequent meals to avoid overloading the stomach.
      • Gradually sip clear liquids between meals, being careful not to gulp excess air.
      • Avoid foods with strong smells. If needed, cook foods outdoors to minimize smells.
      • Use plastic, wood or bamboo utensils.
      • Take medications as prescribed.

      Dry mouth

      Some cancer treatments and medications can cause dehydration and decreased saliva production. This leads to uncomfortable dry mouth.

      Follow these tips to prevent sores and cavities:
      • Increase fluid intake.
      • Create extra saliva by chewing gum or sucking on hard candy or ice chips.
      • Eat soft foods like avocado, applesauce or eggs.
      • Use balm to keep lips moist.
      • Suck on sugarless candy or chew sugarless gum. Avoid mentholated candy.

      Taste changes

      Dry mouth and a general decrease in saliva can change the way that foods taste. In some cases, a complete lack of taste can make foods unappealing.

      If this occurs, try these tips:
      • Chew gum or suck on hard candy to change the flavor in the mouth.
      • Increase amount of seasoning in foods.
      • Use nonmeat protein sources, like tofu, beans or lentils, if meat is unappealing.
      • Use plastic, wood or bamboo utensils and dishes.
      • Make foods that look and smell appealing.

      Sore throat or mouth

      A side effect of some chemotherapy and radiation treatments is a sore throat or mouth. This can make eating and drinking uncomfortable and painful.

      Follow these tips:
      • Eat foods and drinks at a moderate temperature. Very hot or cold foods can be irritating.
      • Choose soft, bland foods like mashed potatoes or bananas.
      • Avoid spicy or acidic foods.
      • Use topical numbing cream if sores are present.
      • Use a blender to smooth out foods.
      • Take pain medication before mealtimes.
      • Keep mouth clean and lips moist.
      • Rinse mouth before and after meals with plain water.

      Diarrhea and constipation

      Bowel changes are unpleasant but common side effects in people receiving treatment for cancer. Diarrhea may just be an uncomfortable problem, or a sign of something more serious. Diarrhea also can lead to other problems, such as severe dehydration. Chemotherapy, pain medications, dehydration or being less active can cause constipation.

      Patients should modify their diets and behaviors if they start to experience:
      • Diarrhea
        • Eat small, frequent meals and snacks.
        • Choose soft, low-fiber foods.
        • Avoid caffeine.
        • Limit alcohol.
        • Limit dairy products.
        • Drink plenty of room temperature fluids but less with meals and more between meals.
        • Take medications as prescribed. Ask your health care team before using any over-the-counter diarrhea medication.
        • Avoid extremely hot meals. Hot or very warm meals can increase the speed food moves through your digestive system.
      • Constipation
        • Drink plenty of fluids, at least 64 ounces per day.
        • Eat prunes or drink prune juice.
        • Keep regular mealtimes.
        • Increase activity.
        • Use a stool softener.

      It's important to do what you can to maintain calorie, protein and fluid intake during cancer treatment. Following dietary guidelines carefully helps patients maintain strength and stamina during treatment.

      Keep in mind that in some cases, such as advanced cancer, eating may not affect the outcome of your illness or treatment. In these situations, trying to follow specific dietary guidelines, such as adhering to a low-sodium or low-fat diet, may not be practical.

      Talk with your care team about what you can expect during treatment and how long symptoms could last. Discuss all your symptoms with your health care team, especially those that affect your diet.

      Watch the annual Lloyd & Ardis Peterson Cancer Symposium to gather more diet tips and hear from author Brenda Elsagher, who offers a humorous account of her personal cancer experience:

      Rose Prissel is a Mayo Clinic dietitian in Rochester, Minnesota.

      Topics in this Post
      • Nutrition
      • Cancer

      Related Posts

      Roasted sweet potatoes with herbs Plant power: Using diet to lower cancer risk
      Healthy food dish Nourishing your health: Diet and nutrition factors for cancer prevention
      Woman Lifting Weights by Healthy Food Healthy food, lifestyle can help prevent cancer
      Mayo Clinic Health System
      About Us
      Careers
      Volunteer
      Donate
      Contact Us
      Patient Care
      Patients & Visitors
      Classes & Events
      Mayo Clinic Connect
      Mayo Clinic
      Resources
      Referrals
      Community Resources
      Financial Assistance
      Price Transparency
      Compliance
      Notice of Nondiscrimination
      Notice of Privacy Practices
      No Surprises Act
      Terms of Use
      Manage Cookie
      Privacy Policy
      © 2018 - 2026 Mayo Clinic Health System