Benefits of good nutrition during cancer treatment

When you’re healthy, eating enough food to get the nutrients and calories you need is not usually a problem. Most nutrition guidelines stress eating lots of vegetables, fruits, and whole-grain products; limiting the amount of red meat you eat, especially meats that are processed or high in fat; cutting back on fat, sugar, alcohol, and salt; and staying at a healthy weight. But when you’re being treated for cancer, these things can be hard to do, especially if you have side effects or just don’t feel well.

Good nutrition is especially important if you have cancer because both the illness and its treatments can change the way you eat.   They can also affect the way your body tolerates certain foods and uses nutrients.

During cancer treatment you might need to change your diet to help build up your strength and withstand the effects of the cancer and its treatment. This may mean eating things that aren’t normally recommended when you are in good health. For instance, you might need high-fat, high-calorie foods to keep up your weight, or thick, cool foods like ice cream or milk shakes because sores in your mouth and throat are making it hard to eat anything. The type of cancer, your treatment, and any side effects you have must be considered when trying to figure out the best ways to get the nutrition your body needs.


  • Feel better.
  • Keep up your strength and energy.
  • Maintain your weight and your body’s store of nutrients.
  • Better tolerate treatment-related side effects.
  • Lower your risk of infection.
  • Heal and recover faster.

Eating well means eating a variety of foods to get the nutrients your body needs to fight cancer. These nutrients include proteins, fats, carbohydrates, water, vitamins, and minerals.





Fats play an important role in nutrition. Fats and oils serve as a rich source of energy for the body. The body breaks down fats and uses them to store energy, insulate body tissues, and transport some types of vitamins through the blood.

You may have heard that some fats are better for you than others. When considering the effects of fats on your heart and cholesterol level, choose monounsaturated (olive, canola, and peanut oils) and polyunsaturated fats (these are found mainly in safflower, sunflower, corn, and flaxseed oils and seafood) more often than saturated fats or trans fats.









Vitamins and minerals

Your body needs vitamins and minerals to help it function properly and use the energy (calories) in food. Most are found naturally in foods, but they are also sold as pill and liquid supplements.

If you eat a balanced diet with enough calories and protein you will usually get plenty of vitamins and minerals. But it can be hard to eat a balanced diet when you’re being treated for cancer, especially if you have treatment side effects. If you do have side effects, your doctor or dietitian may suggest a daily multivitamin and mineral supplement. If your food intake has been limited for several weeks or months because of the effects of treatment, be sure to tell your doctor. You might need to be checked for vitamin or mineral deficiencies.




Antioxidants include vitamins A, C, and E; selenium and zinc; and some enzymes that absorb and attach to free radicals (destructive molecules) , preventing them from attacking normal cells.






Dietary supplement safety considerations






The American Cancer Society medical and editorial content team


Last Revised: July 15, 2019

Last Revised: July 15, 2019
