Cancer Treatment Side Effects and Diet

Dietary interventions for cancer patients are designed to maintain adequate oral nutrition intake while attempting to treat or alleviate the symptoms caused by cancer or the cancer treatment. For the purpose of this educational activity, the focus is on nutrition for cancer treatment side effects rather than nutrition for cancer prevention. It is important to note that diet recommendations vary among patients depending on their symptoms and side effects.

The type of cancer, location, treatment, and side effects determine the nutrition intervention needed. The object of most cancer treatment is simple: destroy the cancer cells. Unfortunately, healthy cells often get damaged along the way and this is the source of the side effects.

Diet intervention is used to treat a multitude of cancer treatment side effects. These include:

The objective is to minimize these symptoms and to provide adequate nutrition to keep the patient strong during and after cancer treatment. A healthcare professional’s responsibility is to encourage patients and make suggestions for achieving adequate nutrition intake. Unfortunately, dealing with these side effects can be tiring for the patient, both physically and emotionally, contributing to his or her inability to consume appropriate nutrition. Encouraging a patient to enlist the help of family and friends or mental healthcare professionals is appropriate if needed. The following information provides guidelines and suggestions/survival skills for dietary treatment of the side effects listed earlier.

Weight Loss

If weight loss alone is the problem without concurrent nausea, vomiting, diarrhea, or other problems, a high calorie, high protein diet may be recommended. Keep in mind that to increase calories and protein during this time, suggestions may seem contradictory to conventional nutritional or healthy eating advice. That is because this diet is treating the specific problem of weight loss. This is a temporary diet until weight and medical condition are satisfactory.

Weight Loss Survival Skills

Lack of Appetite/Early Satiety

Often a diet of six small meals is ordered to provide frequent limited volumes with the goal of increasing total intake for the day. It is also important to keep in mind that the patient’s emotional status plays a significant role in appetite levels. Recognizing this and providing the patient with emotional support or referring him/her to the appropriate mental health professional may assist with appetite problems.

Lack of Appetite/Early Satiety Survival Skills

Painful or Dry Mouth and Throat

Mouth pain or dryness is often a result of cancer treatment. While there are medications and oral treatments to ease pain and encourage healing, eating acidic foods or foods with a firm consistency may worsen the situation. Often a soft, bland diet is the diet order of choice.

Painful or Dry Mouth and Throat Survival Skills

Taste and Smell Changes

Taste and smell are strongly linked and affect appetite. Even foods that normally have a pleasant aroma may not be appealing to the patient. There is no specific diet order for this. However, there are some suggestions that may help.

Taste and Smell Changes Survival Skills

Nausea and Vomiting

Many of the preceding suggestions may also help when nausea and vomiting are an issue. There is no specific diet order, except when a patient has an acute bout of intractable nausea and vomiting. In that case, the diet order is a progression from clear liquids (water, juice, broth, popsicles) to thicker liquids, soft foods, and then regular foods if tolerated.

Nausea and Vomiting Survival Skills


When a patient has diarrhea, re-hydration with water and sodium- and potassium-containing beverages (sports drinks, fruit juices, broths) is important. The diet recommended might be low fiber, low residue, increase oral fluids. This type of diet limits the amount of material that is not easily digested, such as fiber in fruits and vegetables and the lactose (milk sugar) in milk in an effort to decrease the volume going through the colon.

Diarrhea Survival Skills


Pain medications may cause or exacerbate constipation. The diet ordered is usually high fiber with adequate fluid, the goal being to increase stool size and softness for easier passage.

Constipation Survival Skills

These survival skills provide basic ideas to help cancer patients in coping with treatment side effects. Ultimately, whatever works best for the patient, even unconventional food, is the best diet plan. Keep in mind that encouragement and food experimentation are the only ways to find a diet solution.