Nutrition Recommendations During and After Treatment

Approved by the Cancer.Net Editorial Board, 06/2019

People with cancer need to maintain a healthy body weight and eat nutritious foods. Sometimes the side effects of cancer treatment can cause a person to eat less and lose weight. Losing weight without trying can make you weak and malnourished. On the other hand, some cancer treatments may cause weight gain.

Nutrition guidelines during cancer treatment

Here are some general nutrition recommendations for people receiving cancer treatment:

  • Maintain a healthy weight. For many people, this means avoiding weight loss by getting enough calories every day. For people who are obese, this may mean losing weight. Ask your health care team if you should try to lose weight during treatment. It may be better to wait until after treatment so that you have all the nutrition you need to stay strong. If you do try to lose weight during treatment, it should be moderate, meaning only about a pound a week.

  • Get essential nutrients. These include protein, carbohydrates, fats, and water.

  • Be as active as you can. For example, take a daily walk. If you sit or sleep too much, you may lose muscle mass and increase your body fat, even if you are not gaining weight.

Ways to get essential nutrients and manage a healthy weight

Nutrition counseling may help people with cancer get essential nutrients, such as protein, vitamins, and minerals. It can also help them maintain a healthy body weight.

For nutrition counseling, it is important to visit a qualified professional. This means a registered dietitian (RD) or a registered dietitian nutritionist (RDN). Ask your health care team to help you find one of these professionals. You can also find a dietitian through the Academy of Nutrition and Dietetics.

Dietitians and other nutrition experts can help you create a diet that meets your specific nutritional needs. Their recommendations may include:

  • Vitamins or minerals that you are not receiving enough of

  • Liquid nutritional supplements and snacks to help reach your goal

  • Feeding tubes or nutrition support appropriate for your body

Side effects and nutrition

Cancer treatment often causes side effects, such as diarrhea, nausea, mouth sores, and taste changes. These side effects may make it difficult to eat or drink. Follow these tips to help you get the nutrition you need:

  • If water tastes unpleasant to you, take in more liquid through foods and other drinks. For example, eat soup or watermelon and drink tea, milk, or milk substitutes. A sports drink is another option. There are sugar-free ones available for people watching their blood glucose. You can also flavor your water by adding a little bit of fruit juice.

  • If food tastes bland, try seasoning it with flavorful spices. For example, try using lemon, garlic, cayenne, dill, and rosemary. If your mouth is sore, you may need to choose non-acidic and non-spicy foods until it heals.

  • Eat 6 small meals throughout the day instead of 3 large meals. Make sure you reach your calorie goal with these smaller meals.

  • If meat is no longer appealing, get protein from other foods. For example, try fish, eggs, cheese, beans, nuts, nut butters, tofu, or high-protein smoothies or shakes.

  • If you have a metallic taste in your mouth, suck on mints, chew gum, or try fresh citrus fruits. Use plastic utensils and cook in nonmetal pots and pans. Also, try brushing your teeth or rinsing your mouth before eating.

  • If you have mouth sores or a gum infection, use a blender or food processor to make the texture of vegetables and meats smooth. For added smoothness and more calories, add butter, mild sauces, gravy, or cream. Try juicing or making smoothies because the extra moisture can help soothe a sore mouth.

Some side effects are often treated with medication. If your side effects are affecting your hydration and nutrition, talk with your health care team.

The use of dietary supplements

Low-dose dietary supplements, such as multivitamins, may be helpful for people with cancer who are not able to get all of their nutrients through food. Multivitamins are dietary products that contain most of the required daily vitamins, minerals, and trace elements. They may also contain some minerals such as calcium, magnesium, or iron. They are typically taken by mouth as a pill, capsule, tablet, liquid, or powder. High doses of specific nutrient supplements can be harmful. It is unknown if some of these could affect your treatment so talk with your doctor before taking any supplements.

Ask your health care team the following questions about dietary supplements:

  • What are the benefits of taking this dietary supplement?

  • What are the possible side effects?

  • Are there risks to taking it?

  • Can taking dietary supplements interfere with my cancer treatment?

  • How much should I take and for how long?

  • Where can I learn more about dietary supplements?

Read more about dietary and herbal products.

Food safety

People having cancer treatment should be aware of food safety. Some treatments may weaken the immune system, and this can raise the risk of an infection. A food-borne infection happens when harmful bacteria, viruses, or fungi contaminate food and make you sick. Here are some basic food safety tips to reduce the risk of infection:

  • Wash your hands before and while you handle and prepare food.

  • Rinse vegetables and fruit thoroughly before eating them.

  • Handle and store food safely. For example:

    • Use separate cutting boards for meats and vegetables

    • Store meat and fish on the bottom shelf of the refrigerator

    • Do not thaw food on the counter or under warm running water

    • Refrigerate food right after everyone has been served

  • Eat fully cooked foods. For example, do not eat eggs that are not cooked solid, and do not eat raw fish, oysters, or shellfish.

  • Do not eat or drink unpasteurized foods. This includes beverages such as unpasteurized cider, raw milk, and fruit juices, and foods such as cheeses made from unpasteurized milk.

  • Make sure the food that you purchase is not past its sell by or expiration date, and follow directions on proper storage.

Read more about food safety during and after cancer treatment.

Diet and nutrition after treatment

Most nutrition recommendations include eating a diet high in fruits, vegetables, and whole grains. The effect of specific dietary factors on cancer survival rates is not yet well understood. But a healthy diet is important for cancer survivors because they may have a higher risk of other health conditions, such as heart disease, type 2 diabetes, and weakening of the bones.

To lower the risk of other diseases, doctors generally recommend that cancer survivors follow common recommendations for good health. These include:

  • Eating a nutrient-dense and plant-based diet

  • Quitting smoking

  • Maintaining a healthy weight

  • Minimizing alcohol consumption

  • Staying physically active

Related Resources

Spotlight On: Oncology Dietitians

3 Steps to a Clean and Safe Fridge for People With Cancer

Cancer and Food Anxiety: What to Know and What to Do?


Managing Eating Challenges After Head and Neck Cancer Treatment

More Information

Fight Bac: The Core Four Practices

National Cancer Institute: Nutrition in Cancer Care and Eating Hints: Before, During, and After Treatment