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If you or a loved one has been diagnosed with cancer, you probably have a lot of questions about the role nutrition plays in cancer and cancer treatment.

Nutrition advice is everywhere, but it’s not all good information. Be cautious of nutrition advice online, in magazines or advertisements, and from well-meaning family and friends. Make sure you get nutrition information from a reliable source by talking to a registered dietitian.

Below, you will find answers to the common questions our dietitian hears from cancer patients and caregivers.

Does sugar cause cancer?

Sugar does not directly cause cancer. You can have small amounts of sugar, even after a cancer diagnosis. Weight loss and malnutrition is a concern for many cancer patients. Too many food restrictions such as completely eliminating foods with sugar may keep cancer patients from eating enough or cause unnecessary stress. It takes lots of time, energy, and resources to limit all sugar in a menu. Aim for a healthy amount of sugar intake daily less than 10 percent of your calories. Read more.

If you frequently go over the recommended limits for daily sugar intake, you should take steps to reduce your intake. Other reasons to reduce daily sugar intake include:

  • Diabetes, pre-diabetes, insulin resistance, or elevated blood glucose readings
  • Sugary foods consistently replace healthier foods in your menus
  • Working to achieve a healthy weight or avoid unwanted weight gain

For tips to reduce sugar intake, read more.

How much protein should I eat?

Protein is essential to life. Protein is unique in that it is not stored by the body like carbohydrates and fats. It is imperative that protein is consumed on a daily basis. The result of dividing your ideal weight in pounds by 2 is the minimum number of grams of protein your body needs on a daily basis. This is about 1 gram of protein per kilogram of body weight (1kg = 2.2 pounds). The protein requirement could reach 2.5 grams per kilogram of body weight if the body is experiencing extreme muscle wasting as a result of cancer or cancer treatment. A registered dietitian can assess protein status and determine individual protein requirements. Read more.

What does organic mean?

Organic foods are grown with the environment in mind and preserve natural resources like soil and water. Organic produce is grown without prohibited substances, which includes most synthetic fertilizers and pesticides. For meat products, organic means the animals were given organic feed, free of antibiotics and growth hormones, and had access to the outdoors, including fields for grazing. For the word “organic” to be on a label, the product must meet certain United States Department of Agriculture (USDA)-approved guidelines. Read more.

Remember: Eating plenty of fruits and vegetables, whether they are organically or conventionally grown, is the most important.

Should I be taking supplements?

Always ask your healthcare team before taking any new supplements. Make sure your healthcare team knows all the supplements you are currently taking. The best way to provide your body the nutrients, vitamins, and minerals you need is through healthy food choices. Read more.

How does meat affect cancer risk?

The American Cancer Society and American Institute for Cancer Research recommend people limit their consumption of red meat and processed meat. This is because there is convincing evidence linking red meat and processed meat consumption to an increased risk for colorectal cancer. It is recommended to limit red meat to 18 ounces or less (cooked) per week. Red meat includes beef, pork, and lamb.

To limit your intake of red or processed meats, choose protein rich alternatives such as poultry, fish, eggs, beans, tofu, other minimally processed soy foods, low-fat dairy products, and nut butters. Read more.

I have diabetes and cancer. What should I eat?

Having diabetes during cancer treatment may pose some additional challenges, but with proper monitoring and extra care, you can complete your cancer treatment with minimal difficulty. Talk to your healthcare team about diabetes and cancer. Check out our guidelines to help you best manage your diabetes during cancer treatment. Read more.

Should I be juicing?

Juicing extracts the juice from fruits and vegetables using a juicer or a blender. Fruits and vegetables are great sources of antioxidants. Antioxidants help fight cancer. While juicing does offer several health benefits, people with cancer or those undergoing cancer treatments should not follow an “all juice” diet. Juice can not give your body everything it needs. Always remember, juicing is a great way to add fruits or vegetables to your diet, but should not be used to try to meet all of your nutrition needs. Read more.

If I am on blood thinning medications, do I need to watch my vitamin K intake?

Blood thinning medications (also called anticoagulants) are prescribed for increased risk for developing a blood clot. Vitamin K is a vitamin that aids in blood clotting. When too much vitamin K is consumed through foods, drinks, and supplements, it interferes with blood thinning medications as well as the blood test that measures clotting time. It is most important to be consistent with vitamin K intake. Large variation or fluctuations in intake pose a problem when attempting to regulate clotting time and medication dosage. Read more.

Why should I lower my sodium (salt) intake, and how can I eat less sodium?

Salt is present in nearly every food we eat. Before the salt shaker even makes an appearance, most foods and drinks contain some sodium. The average person consumes about 3500  milligrams (mgs) of sodium per day. This is more than twice as much as what is recommended.

The American Heart Association recommends no more than 2,300 mgs a day and an ideal limit of no more than 1,500 mg per day for most adults. Talk with your healthcare team to determine your daily sodium goal. If you are on a meal plan that controls sodium, pick foods mostly that have 300 mg or less of sodium per serving. To eat less sodium, you will have to move beyond your use of the salt shaker. Read more.

What is portion control, and why is it important?

Portion control means choosing a healthy amount of a certain food. Portion control helps you get the benefits of the nutrients in the food without overeating and is key to controlling or reversing weight gain. Read more.

How much water should I drink?

The “8 X 8 rule” is a good place to start. Aim to drink 8, 8 ounce glasses of caffeine-free fluid a day. Drink fluids throughout the day instead of waiting to drink when you feel thirsty. Your fluid needs can change based on side effects or other health conditions. Ask your healthcare provider for a specific fluid goal per day. Did you know some foods can also count to your daily fluid goal? Read more.

What are feeding tubes?

A feeding tube is a tube into the stomach or intestines through which liquid nutrition can be administered. This process is called nutrition therapy. Cancer and cancer treatments can affect the way you eat and drink. Nutrition therapy provides ways to get nutrients and fluids when you are unable to eat. The goal of nutrition therapy is to offer enough nourishment to avoid unhealthy weight loss and/or dehydration. There are multiple ways to receive nutrition therapy. Read more.

What are Omega 3 fatty acids, and how can I include them in my meals?

Omega-3 fatty acids are essential fatty acids that are not produced by the body, which means we have to get them from food sources or supplements. These fatty acids have health benefits such as, promoting cell and heart health, reducing inflammation, and enhancing brain and nerve development. They’re also best used by the body when in food form. Ask your healthcare team or a dietitian how much Omega-3 you need. Read more.

How much fiber should I eat?

Fiber is a very important component of a healthy diet. During cancer treatment, the amount of fiber you need may change based on many factors. For example, if you’ve underwent surgery to your digestive tract, you may need to avoid fiber to allow your digestive tract to heal. If you experience constipation as a side effect, you may need to increase your fiber intake to help with bowel regularity. Talk to your healthcare team or a registered dietitian to find out your daily fiber goal.

Did you know there are actually two types of fiber? To learn more about fiber and the fiber content of specific foods, read more.


I'm participating in a clinical trial. What should I eat?

Eating well during a cancer clinical trial has a direct impact on the body.  It helps improve overall well being, enhances response to treatment, enables health maintenance during treatment, and decreases recovery time.

As a participant in a clinical trial, make sure you communicate well with your healthcare team and the research team. Ask if there are any foods you should avoid as part of the trial. Do not start taking any new supplements or medications without alerting the healthcare team involved with the clinical trial. Always alert your healthcare team to new or worsening symptoms.

For more guidelines to follow while participating in a clinical trial, read more.

What foods can I eat to boost my immune system?

Since the immune system is not just a single entity, there also isn’t a single food that you can eat or add to your diet to boost your immune system, especially not overnight. The best way to keep your immune system running smoothly is to follow healthy-living strategies. Read more.

What does the information on the Nutrition Facts Label mean?

The Nutrition Facts label, found on all packaged foods, follows guidelines set by the U.S. Food and Drug Administration (FDA). The information on the label gives you the information you need to make good food choices such as the amount of calories and nutrients in the food. Read more. 

If you have questions not addressed in our FAQs, schedule a one-on-one consultation with our registered dietitian for answers to all your questions.