• Nutrition is a process in which food is taken in and used by the body for growth, to keep the body healthy, and to replace tissue.
• Good nutrition is important for good health.
• Eating the right kinds of foods before, during, and after cancer treatment can help the patient feel better and stay stronger.
• A healthy diet includes eating and drinking enough of the foods and liquids that have important nutrients (vitamins, minerals, protein, carbohydrates, fat, and water) the body needs.

A registered dietitian is an important part of the healthcare team.

• A registered dietitian (or nutritionist) is a part of the team of health professionals that help with cancer treatment and recovery.
• A dietitian will work with patients, their families, and the rest of the medical team to manage the patient’s diet during and after cancer treatment.

Cancer and cancer treatments may cause side effects that affect nutrition.

For many patients, the effects of cancer and cancer treatments make it hard to eat well. Cancer treatments that affect nutrition include:

• Chemotherapy
• Hormone therapy
• Radiation therapy
• Surgery
• Immunotherapy
• Stem cell transplant

When the head, neck, esophagus, stomach, intestines, pancreas, or liver are affected by the cancer treatment, it is hard to take in enough nutrients to stay healthy.

Cancer and cancer treatments may cause malnutrition.

• Cancer and cancer treatments may affect taste, smell, appetite, and the ability to eat enough food or absorb the nutrients from food.
• This can cause malnutrition, which is a condition caused by a lack of key nutrients.
• Alcohol abuse and obesity may increase the risk of malnutrition.
• Malnutrition can cause the patient to be weak, tired, and unable to fight infection or finish cancer treatment.
• Malnutrition may be made worse if the cancer grows or spreads.
• Eating the right amount of protein and calories is important for healing, fighting infection, and having enough energy.

Anorexia and cachexia are common causes of malnutrition in cancer patients.

• Anorexia is the loss of appetite or desire to eat. It is a common symptom in patients with cancer.
• Anorexia may occur early in the disease or later, if the cancer grows or spreads. Some patients already have anorexia when they are diagnosed with cancer.
• Most patients who have advanced cancer will have anorexia. Anorexia is the most common cause of malnutrition in cancer patients.
• Cachexia is a condition marked by weakness, weight loss, and fat and muscle loss. It is common in patients with tumors that affect eating and digestion.
• Cachexia can occur in cancer patients who are eating well, but are not storing fat and muscle because of tumor growth.
• Some tumors change the way the body uses certain nutrients.
• The body's use of protein, carbohydrates, and fat may be affected, especially by tumors of the stomach, intestines, or head and neck.
• A patient may seem to be eating enough, but the body may not be able to absorb all the nutrients from the food.
• Cancer patients may have anorexia and cachexia at the same time.