Nutrition & Cancer Treatment

Nutritional needs may vary during cancer treatment. Diet not only affects physical health, but also the ability to handle emotional stress. Eating right can help patients cope with the physical and emotional challenges of a cancer diagnosis and treatment.

For patients who have been diagnosed with cancer, good nutrition is important for many reasons. Eating well can help patients:

  • Avoid vitamin and mineral deficiencies
  • Better tolerate side effects of treatment
  • Feel better
  • Heal and rebuild tissue
  • Keep a healthy weight
  • Lower the risk for infection
  • Maintain strength and energy
  • Recover as quickly as possible

Before treatment, patients should focus on taking care of themselves and make sure to eat a healthy diet. To prepare for possible changes in nutritional needs:

  • Ask a health care provider or a registered dietician about what to eat during treatment.
  • Choose foods that need little preparation. Foods such as pudding (milk- or soy-based), peanut butter, and eggs are easy to have on hand and prepare. They also contain protein, vitamins, and minerals.
  • Prepare well-liked foods in advance and freeze them in meal-sized portions for quick, ready-made meals.
  • Keep foods on hand that are appealing.

Avoid high-risk foods, such as under- and uncooked meats or fish. Limit alcohol to 1 drink per day for women and 2 drinks per day for men. Talk to a health care provider about how alcohol may affect treatment.

Avoid shark, swordfish, king mackerel, and tilefish due to potentially high levels of mercury. Talk with a health care provider about the safety of fish and seafood during cancer treatment.

Information and advertising about vitamin, mineral, and herbal supplements that may help during cancer treatment can be overwhelming. Large doses of some vitamins and minerals may interfere with treatment and most herbal supplements have not been tested for safety or effectiveness when used by people undergoing standard cancer treatments. Always talk with a qualified health care provider before taking any vitamin, mineral, or herbal supplement.

During treatment, diet should help patients build strength and maintain a healthy weight to withstand possible side effects. Treatment plans vary, and patients should follow the advice of a health care provider about what to eat and what to avoid. Some patients are referred to a dietician. It often is helpful to write down any questions ahead of time and ask for clarification about anything that isn't made clear.

Diet recommendations during cancer treatment may be very different from a normal diet. To maintain a healthy weight, patients may be advised to add extra calories (e.g., from butter, cream, and salad dressings). Patients may be encouraged to drink milk shakes or liquid meal replacements, or to eat pudding, ice cream, or nutrition bars to help supply necessary calories.

Because some healthy cells may also get damaged during cancer treatment, the body may need extra protein to help rebuild itself. Good sources of protein are meats, fish, poultry, eggs, milk, yogurt, cheese, beans, and nuts.

The following suggestions can help add protein to the diet:

  • Sprinkle sunflower seeds or nuts on fruit, ice cream, or pudding.
  • Add peas, beans, or chickpeas to soups and salads.
  • Eat milk-based soups and add cream sauces to vegetables.
  • Add chopped, hard-boiled egg to soups and salads.
  • Add peanut butter to fruit or blend it into a milk or yogurt shake.

Publication Review By: the Editorial Staff at

Published: 28 Feb 2007

Last Modified: 03 Sep 2015