Nutrition, Weight and Cancer Treatment

by Tracie Swearingen, RD, CSO, LD

Nutrition plays a significant role in cancer treatment. Without adequate nutrition, it is very difficult for a patient to receive the treatments needed to fight their cancer. Cancer and its treatments can affect a patient’s eating ability and place a lot of nutritional demand on the body.  It is important for patients to understand the risks of inadequate nutrition and learn ways to improve their intake if they are having difficulty. The main goals during this time are to maintain weight, maintain optimal nutrition status, prevent or control nutrition impact symptoms and maintain quality of life.

Up to 40 percent of patients experience loss of appetite and weight loss prior to diagnosis, and 40-80 percent may experience malnutrition at some point during treatment (1). Malnutrition is when the body doesn’t get or can’t absorb the nutrients needed for health. The effects of malnutrition can impact immune response, muscle strength, fatigue levels, wound healing, psycho-social function, quality of life, tolerance to the treatment regimen and ultimately effect treatment outcome (2).

As little as a 6 percent weight loss predicts a reduced response to oncology treatment, reduced survival and a reduced quality of life (3). This is as little as 9 pounds for a 150-pound person. For most cancer patients, weight loss prevention is of the utmost importance during cancer treatment. Even if a patient feels they have weight to lose, weight loss during cancer treatment is not an appropriate time. Weight loss before and during treatment can reduce the extra energy and nutrients the body stores and can impact recovery. Poor nutrition and weight loss makes it harder for the body to heal and recover from cancer surgery, chemotherapy and radiation (4). Without adequate nutrition with calories and protein, patients lose weight and muscle mass. Loss of muscle mass can affect stamina and energy, which makes it more difficult for patients to do daily activities and things they enjoy.

Cancer treatment can cause nutrition impact symptoms. Nutrition impact symptoms can affect oral intake, which can ultimately lead to weight loss. They can include loss of appetite, nausea, vomiting, diarrhea, constipation, sore mouth, difficulty swallowing, changes in taste and smell, pain, depression and anxiety (5). It is important to talk with your Oncology Physician, Registered Nurse or Dietitian if these affect your ability to eat, become bothersome or interfere with your quality of life. They can provide assistance in reducing these side effects or help to make them more manageable.

Cancer patients may also have increased calorie and protein requirements as a result of the metabolic effects from the cancer and its treatment (6). It has been noted that people diagnosed with head and neck, esophageal, gastric, pancreatic and non-small cell lung cancers have higher energy expenditures (6). Energy expenditure refers to the amount of energy (calories), that a person uses to breathe, circulate blood, digest food, and to be physically active. This generally means patients will require more calories and protein to maintain their nutritional status and maintain weight. Many patients say “But I eat the same as I used to?” Unfortunately the amount of food intake consumed before diagnosis and treatment may not be enough now to maintain weight.

Tips to maintain optimal nutrition status:

  • Early nutrition intervention is essential. Ask your Physician, Physician Assistant/Nurse Practitioner for a referral to meet with the Oncology Dietitian at your clinic. An Oncology Dietitian will utilize a variety of strategies to help manage side effects of cancer treatment and assist with weight maintenance.  This will increase your tolerance to treatment and help to maintain optimal quality of life.
  • Don’t restrict your diet. During cancer treatment is generally not the best time to try to correct bad eating habits, especially if you are not feeling well. If you can improve eating habits while maintaining your weight, then that is appropriate.
  • Increase your calorie intake if you are struggling to maintain your weight. This can be done by being liberal with your eating and including more calorie dense foods. Adding more fat containing foods to your diet is one way to provide extra calories. Try adding butter, mayonnaise, gravy, olive oil, peanut butter, cheese, whipping cream, sour cream and salad dressing to food when you can.
  • If appetite is an issue, consume smaller and more frequent meals and snacks. Try eating something every couple hours.
  • Have a caregiver shop and prepare meals and snacks for you if eating becomes difficult.
  • Eat adequate protein – including meat, dairy (milk, yogurt, cheese),eggs, nuts, seeds, tofu, beans, peanut butter and nutrition supplement drinks (ex. Ensure, Boost, Carnation Instant Breakfast). A good rule of thumb is to include a protein item every time you eat.
  • Stay hydrated. Fluids to assist with hydration include water, milk, juice, decaf coffee and tea, sports drinks, flavored waters, soups, etc. Choosing fluids with calories will assist with weight maintenance.
  • Remain physically active if tolerated. Activity helps to maintain lean muscle mass and may stimulate your appetite.
  • Do not take any nutrition supplements to counteract poor eating habits, unless recommended by your Physician or Dietitian. Vitamins and other nutrition supplements are not generally recommended during cancer treatment. They may interfere with your cancer treatment and other medications. Make sure to talk with your doctor regarding any vitamins, minerals or herbal supplements you are taking or prior to taking them.

It is important that cancer symptoms and side effects from treatment that affect eating are not overlooked. Weight loss and/or malnutrition can lead to decreased quality of life, increased complication rates, decreased treatment tolerance and increased mortality (7). If you have any concerns regarding your ability to eat adequately during cancer treatment, contact your oncology clinic or notify your Physician.


  1. Ollenschlager G, Viell B, Thomas W, Konkol K, Burger B. Tumor anorexia; causes, assessment, treatment. Recent Results Cancer Res. 1991; 121: 249-259.
  2. Capuacno G, Gentile PC, Bianciardi F, Tosti M, Palladino A, Di Palma M: Prevalence and influence of malnutrition on quality of life and performance status in patients with locally advanced head and neck cancer before treatment. Support Care Cancer 2010;18 (4):433-437.
  3. Shike M. Nutrition therapy for the cancer patient. Hematol Oncol Clin N Am. 1996; 10 (1):221-234.
  5. Wojtaszek CA, Kochis LM, Cunningham RS: Nutrition impact symptoms in the oncology patient. Oncology Issues 17 (2): 15-7, 2002.
  6. Cao D, Wu G, Zhang B, e al. Resting Energy Expenditure and Body Composition in Patients with Newly Detected Cancer. Clin Nutr. 2010; 29(1); 72-77.
  7. Marin-Caro MM, Laviano A, Pichard C. Nutritional intervention and quality of life in adult oncology patients. Clin Nutr. 2007; 26;289-301.




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