Cancer Treatment Nutrition 101: A Guide to Healthful Eating

Cancer Treatment Nutrition 101: A Guide to Healthful Eating

Reviewed by Jasper Clinical Board

Last updated 10/19/21

During cancer treatment and recovery, there’s a lot of focus on your body—and rightly so. As you navigate treatments and side effects (not to mention cancer itself) your physical being is going through a tremendous ordeal, and the way you feed yourself can be hugely impactful during this time. But nutrition for cancer recovery can be tricky, even for those who have their diet super dialed in during normal times.

Why it matters

Losing weight and muscle mass is incredibly common during cancer treatment—this is such a frequent occurrence, in fact, that oncological nutrition it is a whole subspecialty of dietetics. As you move through your treatment journey, side effects like nausea, oral pain, depression, and plain old overwhelm can cause your appetite to skip town, but it’s important to keep eating if at all possible, because the cells of your body need all the help they can get.

Eat what you can eat

First things first: if you’re struggling to eat at all, or to meet your caloric needs (which are typically between 1800 and 2400 calories per day, depending on your age, sex, and activity level), your priority should just be eating whatever you can. If it’s not particularly nutritious, that’s okay—a bowl of white rice is way better than not eating at all. If you can, sneak in extra calories by adding healthy fat like olive oil.


Macronutrients—protein, fat, and carbohydrates—are the building blocks of your diet, and if you don’t have the bandwidth to get super intricate with your nutrition, keeping your focus on this three-part system is your best bet. Simple meals that incorporate a balance of the three are ideal—think chicken breast, sweet potatoes, and broccoli with olive oil, or black beans with tomato and avocado.


During cancer treatment and recovery, your protein needs are higher than they are at other times. This is because treatment causes damage to your healthy cells along with the cancerous ones, and protein helps them repair and rebuild. Lean animal protein is the most nutritionally optimal source (wild-caught salmon, chicken breast, pork tenderloin, and tri tip beef are all great picks), and there are plenty of excellent plant-based sources as well, such as beans, lentils, tempeh, and nuts.


Maybe you’ve heard of free radicals—pesky, unstable molecules that cause cell damage and are implicated in everything from premature aging to heart disease and cancer. They are naturally produced in the body, but habits like smoking, drinking alcohol, and eating fried food can increase them. Their Kryptonite are antioxidants: molecules that fight free radicals by chemically neutralizing them. Find antioxidants in fresh fruits and vegetables—which are also rich sources of the vitamins and minerals your body needs to keep its immune and other systems running as smoothly as possible.


Drinking enough water is always important, but during treatment, it’s even more vital. If you’re doing chemo, the drugs can be extremely dehydrating, and no matter what your treatment protocol is, your body needs all the help it can get to flush itself of toxins. Aim for eight to ten 8 oz glasses of water a day, and if you’re vomiting or having diarrhea, you’ll want to up that number to make up for what you’ve lost.

Eating strategies

During cancer treatment, streamlining the parts of your life that can be simplified may help you cope. Consider reframing food as fuel and medicine—once you know you can easily tolerate a food, make it one of your “safe foods,” and eat from a small menu of those safe foods, day in and day out. Is it boring? Sure, but predictability can be soothing. Bulk meal prepping is a breeze if you eat the same two dinners most nights, too—invest in an Instant Pot and cook a whole week’s worth of ingredients, or a one-pot meal, at once.

Eating with side effects

Side effects from treatment—nausea, in particular—can make eating incredibly difficult. If this is your reality, check out natural remedies with proven efficacy, like ginger and acupressure, and dietary strategies like grazing on small mini-meals and steering clear of spices and strong flavors.

Things to avoid

Just say no to processed foods (especially processed meat), fried food, and refined sugar, which are harmful to your health and can contribute to inflammation. The jury is out on alcohol—while some research does link moderate consumption of red wine with cancer prevention, it is generally accepted in the scientific community that ethanol (aka alcohol) is carcinogenic. No matter which side of the argument you land on, it’s wise to steer clear of alcohol during your course of treatment, when your liver is already working double time.


Ask your oncology team about getting support from an oncology nutritionist or registered dietician—because bodies, cancers, and treatment protocols are all so different, getting 1:1 advice from a trained dietician can help you dial in a specific eating plan that is ideal for your unique body.

The content on this website is intended to provide the best possible information for you, but should not be considered—or used as a substitute for—medical advice. If you have questions about your diagnosis or treatment, please contact your health care provider(s). For questions or comments about this content, please email us at