Ask the Expert: Importance of Nutrition for Cancer Patients

Beth Miller, MS, RDN, CDN, CSO, Oncology Dietitian at Good Samaritan University Hospital, answers frequently asked questions about the critical role of nutrition in a cancer patient’s journey.

Why is nutrition important for cancer patients?

For cancer patients, a tailored eating plan to get recommended nutrients is integral to cancer treatment. Nutrients, such as protein and vitamins, support the growth of healthy cells and help to maintain critical functions such as muscle strength and the immune system.

Cancer patients who meet nutritional requirements throughout treatment are more likely to tolerate their doctor’s recommended chemotherapy or radiation therapy doses. Good nutrition can reduce the impact of common side effects, including fatigue, nausea and weakness. Avoiding significant weight loss during treatment will also promote faster recovery once treatment is completed.

What is the recommended diet for a cancer patient?

The recommended diet for a cancer patient will vary as much as the individual patients themselves! A comprehensive plan should take into account the following: 

• Weight
• Existing medical conditions (such as diabetes or heart disease)
• Activity level
• Lifestyle habits
• Budget
• Symptoms
• Food preferences
• Food-related concerns

A diet will then be created with recommended intakes of protein, calories, vitamins and minerals. Some cancer treatments cause the depletion of specific nutrients, such as potassium and magnesium, that can be replaced with foods rich in these nutrients or with a supplement. 

Avoid supplements unless your oncologist has cleared them because some commonly used products, such as vitamin C and zinc, may interfere with chemotherapy. Nutritious foods are the cornerstone of a cancer patient’s diet because they provide benefits that cannot be replicated in a supplement.

How do I create a nutritionally balanced meal plan?

Start with a good source of protein at each meal—chicken, turkey, seafood, lean red meat or eggs. Or protein-rich plant foods such as beans, lentils, tofu, nuts and seeds. In addition to protein, these foods contain many other essential nutrients, including iron, zinc and B vitamins. 

Include at least one vegetable or fruit at every meal, aiming to have various types over a week. Aim for six or seven other vegetables and two or three different fruits daily if your appetite is good and you can eat more vegetables without becoming overly full. 

A moderate portion of starchy food—pasta, rice, cereal or bread—should also be included in most meals since these foods contain nutrients that help with energy levels. Aim for most of the fat in your meal to be heart-healthy unsaturated fats such as olive oil, avocados, oily fish, nuts and seeds instead of saturated fats predominantly found in high-fat animal products like processed meats, butter, cheese and ice cream. 

To achieve balance, consider your meals over a week and choose healthier foods at least 80% of the time. Allow for inclusion of any favorite foods that fall outside these categories at up to 20% of meals so that the plan meets your need for enjoyment of foods and optimal nutrition.

Should my diet factor in my type of cancer and type of treatment?

Nutrition recommendations will vary greatly depending on cancer type and treatment plan. Certain cancers, such as esophageal, pancreatic and non-small cell lung, usually cause patients to have higher calorie needs than other cancer types like breast, prostate and colon. 

You should eat more food or include more high-calorie options when calorie needs are higher. High-fat foods are often encouraged because they are the most energy-dense; however, some patients with nausea or diarrhea may find that high-fat foods worsen these side effects. Therefore, recommended amounts of these foods should be tailored to calorie needs and tolerance.

Due to swallowing difficulties, a predominantly liquid diet is often necessary for head and neck cancers.

Your nutrition plan will be reviewed periodically throughout treatment and adjusted according to specific needs at a given time. If you receive more than one type of treatment—chemotherapy, surgery, radiation therapy, immunotherapy—your appetite and recommended diet will likely change during different phases. 

What diet helps if I am experiencing nausea and loss of appetite from chemotherapy?

Loss of appetite. Your appetite will likely vary during cancer treatment. Chemotherapy is given in cycles of differing lengths depending upon the drug(s) taken and the specific type and stage of cancer. Side effects of the medications are usually most significant in the days following administration of the chemotherapy and then generally lessen with time. They may return after the subsequent treatment, or side effects may vary the next time. 

Make the most of the times when your appetite improves, and try to eat more. Any small weight losses resulting from eating poorly can often be reversed when eating is less difficult. You may find that large quantities of food on your plate are overwhelming and discourage you from eating. Dietitians recommend:

• Putting small manageable portions on your plate
• Eating a second helping if you feel like it
• Eating frequent small meals every two to three hours

Hydration. Hydration is as important as nutrition during chemotherapy. If feeling full quickly is a problem, it is best to drink only small quantities with the meal and try to take in the most needed fluids between meals. Foods with a high water content, such as fruit, soup and gelatin, will increase fluid intake. Drinks with calories—juice, milk and sports drinks—can be beneficial. Check the label for added high doses of vitamins, which may not be suitable during chemotherapy. If unsure, take a picture of the label and ask your dietitian.

Nausea. Nausea is a common side effect of many chemotherapy drugs and can significantly affect the ability to eat. Bland foods—toast, crackers and dry cereal—eaten regularly in small quantities may help to settle your stomach. Ginger can also reduce nausea and is available in many forms, like ginger ale, tea, hard candies and chews. If you are on blood-thinning medication or have an upcoming surgery, avoid regular use of ginger as it may lead to excessive blood thinning. 

Many people with nausea are sensitive to smells. Avoid cooking foods with a strong aroma, always ventilate the kitchen with an extractor fan or open window, and ask others to prepare meals while you are not in the kitchen. Serving room temperature or cold foods can also reduce exposure to smells.

Medications can be used for managing ongoing nausea to help you feel better and consume the necessary fluids and foods to sustain you during treatment. Your oncologist can help you find the right medication. 

Who oversees my diet and nutrition plan during cancer treatment?

Catholic Health Cancer Institutes in Nassau and Suffolk counties are accredited by the American College of Surgeons Commission on Cancer, giving patients access to a registered dietitian nutritionist (RDN) as part of their health care team.

An RDN consults with you to create a tailored plan based on the following: 

• Cancer type and treatment methods
• Food preferences
• Cooking abilities
• Support with meals from family and friends
• Factors that may affect appetite or ability to eat
• Existing medical conditions
• Current medications 

How can my caregiver help ensure I eat and get the proper nutrients at home?  

Caregivers are vital members of your treatment team as they assist in essential areas, such as transportation to appointments, emotional support and tasks around the home like cooking meals. Caregivers know that your appetite will likely vary and favorite foods may no longer appeal. Keeping ingredients on hand for several meals or snacks can give you options.

Nutritious options include:

• French toast with fruit compote
• Scrambled eggs or an omelet with a small portion of sautéed vegetables and toast
• Cereal with milk and fresh fruit
• Grilled cheese and tomato sandwich
• Peanut butter and jelly sandwich 
• Greek yogurt with fruit
• Homemade soup or stew containing a good source of protein, such as chicken or lentils (freeze leftovers in individual portions)
• Baked fish with lemon, rice and a cooked vegetable
• Grilled chicken, baked potato and a cooked vegetable

Ask your caregiver to give you a small and manageable portion of the meal. View any quantity eaten as a success. If little or none of the meal is wanted, try an alternative that is easy to eat, such as pudding or a smoothie. Premade nutrition shakes can also be helpful but talk to your RDN first to find the most suitable drink.

Should I change my diet when treatment is completed?

As you regain your appetite following treatment, incorporating a healthy diet into your daily lifestyle may help to reduce the risk of cancer returning. Research has shown that eating plant-based foods like vegetables, fruit, beans, whole grains and nuts likely decreases the risk of many cancers. The health-promoting effects of these foods are related to the fiber and the beneficial plant compounds (phytochemicals) they contain. Eating a wide variety of plant-based foods will give you the most significant benefit. 

Learn more about cancer-fighting foods.

Your RDN will work closely with you to create a plan for continued good health.