Eating enough food to get the nutrients and calories you need is not usually a problem when you're healthy. 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 essential if you have cancer because both the illness and its treatments can change how you eat. They can also affect how 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 are only sometimes recommended when you are in good health. For instance, you might need high-protein, high-calorie foods to keep up your weight or thick, cool foods like ice cream or milkshakes 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.
The nutrition needs of people with cancer vary from person to person. Your cancer care team can help you identify your nutrition goals and plan ways to help you meet them. Eating well while you're being treated for cancer might help you:
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.
Proteins
We need protein for growth, to repair body tissue, and to keep our immune systems healthy. When your body doesn't get enough protein, it might break down muscle for the fuel it needs. This makes it take longer to recover from illness and can lower resistance to infection. People with cancer often need more protein than usual. After surgery, chemotherapy, or radiation therapy, extra protein is usually needed to heal tissues and help fight infection.
Good protein sources include fish, poultry, lean red meat, eggs, low-fat dairy products, nuts and nut butters, dried beans, peas and lentils, and soy foods.
Fats
Fats play an essential 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.
Saturated fats are mainly found in animal sources like meat and poultry, whole or reduced-fat milk, cheese, and butter. Some vegetable oils like coconut, palm kernel oil, and palm oil are saturated. Saturated fats can raise cholesterol and increase your risk for heart disease. Less than 10% of your calories should come from saturated fat.
Most trans fats in our diets come from snack foods and baked goods made with partially hydrogenated vegetable oil or vegetable shortening. These sources of trans fats have largely been removed from the food supply in the US. Trans fats are also found naturally in some animal products, like dairy products, in smaller quantities. Trans fats can raise bad cholesterol and lower good cholesterol. Avoid trans fats as much as you can.
Carbohydrates
Carbohydrates are the body's primary source of energy. Carbohydrates give the body the fuel it needs for physical activity and proper organ function. The best sources of carbohydrates – fruits, vegetables, and whole grains – also supply needed vitamins and minerals, fiber, and phytonutrients. (Phytonutrients are chemicals in plant-based foods that we don't need to live but might promote health.)
Fiber is the part of plant foods that the body can't digest. There are 2 types of fiber. Insoluble fiber helps to move food waste out of the body quickly, and soluble fiber binds with water in the stool to help keep stool soft.
Other sources of carbohydrates include bread, potatoes, rice, spaghetti, pasta, cereals, corn, peas, and beans. Sweets (desserts, candy, and drinks with sugar) can supply carbohydrates but provide minimal vitamins, minerals, or phytonutrients.
Water
Water and liquids or fluids are vital to health. All body cells need water to function. If you don't take in enough fluids or if you lose fluids through vomiting or diarrhea, you can become dehydrated (your body doesn't have as much fluid as it should). If this happens, the fluids and minerals that help keep your body working can become dangerously out of balance. You get water from the foods you eat, but a person should also drink about four 8-ounce glasses of liquid daily to ensure that all the body cells get the fluid they need. You may need extra fluids if you're vomiting, have diarrhea, or even if you're just not eating much. Remember that all liquids (soups, milk, even ice cream, and gelatin) count toward your fluid goals.
Written by The American Cancer Society medical and editorial content team. Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing. To read the full article: https://www.cancer.org/cancer/survivorship/coping/nutrition/benefits.html