Although a given diet cannot prevent or cure cancer, good nutrition can reduce disease risk as well as improve quality of life, immune function, healing, and even survival. That’s good news.
Practically speaking, this begs the questions: What is good nutrition? What should I eat, and what should I consume for the best benefit?
I’m not going to present a list of good or bad foods or do’s and don’ts because the best diet for anyone, but particularly in the context of cancer, is different from one person to the next—there’s no cookie-cutter answer. It is important to think about what your nutrition goals are, both in the present and over the long term, and consider big-picture best practices.
General Guidelines for Good Nutrition
Keeping in mind the importance of individual variability and needs, for most people an ideal diet has some common characteristics: it is mostly plant based, with the right amount of calories to maintain a healthy weight and lean body mass, and it includes a variety of whole vegetables and fruits and minimal added sugars. The American Cancer Society suggests limiting alcohol intake and minimizing red and processed meats. An ideal diet is sustainable, flexible, and long term—it’s a lifestyle. Following a balanced diet is not the same things as “going on a diet.”
Of course, there are always exceptions. Cancer symptoms and treatment side effects may mean you have to adjust your diet. Here are some examples:
- If you are experiencing acute diarrhea, you would want to reduce fiber-rich vegetables and whole grains and instead choose white rice and plain toast.
- If you have changes in taste that make it hard to drink plain water, which is important to stay hydrated, try flavored seltzer or add cucumber or lemon to your water.
- If you feel nauseated, it might be best to avoid hot foods or foods with strong odors and instead try cool, bland foods, as well as ginger tea.
- Always ask to speak with a registered dietitian or nutritionist if you have specific concerns.
Remember, do your best at any given point to eat healthfully without making yourself miserable or worrying that your food choices are hurting you. If you have had no appetite for days and have lost weight and then one day you crave chocolate-chip cookies, let yourself have them—and enjoy them.
Weight Gain or Loss Associated with Treatment
Unplanned weight loss and weight gain may occur during and after cancer treatment. These changes can
be related to the disease itself, behavioral changes, medications, and other factors. Some types of cancer are more associated with weight gain, others with weight loss. For example, about half of women who receive adjuvant treatment for breast cancer gain weight; women and men treated for head and neck cancer lose weight.
Either gaining or losing too much weight can be a problem. In the setting of breast cancer, for example, undesired weight gain may increase recurrence risk, other disease risk, and risk of death. On the flip side, excess unintentional weight loss and underweight are associated with poorer outcomes. Excess or insufficient body weight can also compromise healing, immune function, and quality of life, including one’s mood, social well-being, and energy level.
If you gain excess weight during treatment, be assured that while losing weight is never easy, it is still possible. One of the best places to start is keeping a written food diary: this immediately increases your accountability and makes you more aware of your food choices. Portion control is also very important. I find that many people are not eating foods that are unhealthy—they’re just eating too much. Go slowly and eat mindfully. Your brain needs at least 20 minutes to recognize that your stomach is full. If you rush through a meal you’ll often end up overeating. Learn to read your body’s natural appetite and satiety cues; if you tend to eat when you’re not physically hungry—and we all do that sometimes—check in with what you really need and want. If you are very tired or stressed, for example, you would probably feel better by sitting down with a favorite book or calling a friend or going for a walk. Always have something you’re looking forward to beyond your next meal or snack.
On the other hand, if you have lost weight without wanting to, be patient with yourself. Sometimes it’s best to set an immediate goal of maintaining your current weight rather than putting pressure on yourself to regain. Increase your intake gradually, eating frequently in small amounts that don’t feel overwhelming. Homemade shakes and smoothies can add calories without making you feel overfull. You might want to try a smoothie, for example, made with almond milk, cocoa, a banana, and honey. Commercial supplement drinks are also available. Try to choose foods that will give you some pleasure, and incorporate foods that are high in calories (don’t be afraid to have full-fat rather than low-fat versions of food).
Keep Calm and Carry On
Making good choices about nutrition can be an empowering step you can take during and after cancer treatment. If you need guidance about what the best choices are, given your unique needs, diagnosis, and treatment, speak with your care team.
Cara Anselmo, MS, RDN, CDN*, is an outpatient dietitian-nutritionist at Memorial Sloan Kettering Cancer Center and a certified yoga instructor in New York. Her special interests include plant-based diets, oncology nutrition, and weight reduction and management. She has been teaching yoga, both at New York Yoga studio and privately in Manhattan, since 2007. Cara earned her master of science degree in clinical nutrition from New York University in 2007 and completed her dietetic internship at New York University Medical Center. She has a bachelor of arts degree in English from Brown University.*