5 questions about nutrition and cancer with an Oncology Dietitian - NFCR


5 Questions About Nutrition and Cancer with an Oncology Dietitian

Nichole Giller, RDN

After diagnosis, cancer patients have a lot to manage. Oncology dietitian Nichole Giller works with patients to reduce the confusion around diet during and after cancer treatment. Giller said her work is rewarding because she can discuss modern research with cancer patients and survivors in hopes of giving them the confidence to eat the foods they love while optimizing treatment outcomes. We asked Giller five questions about how cancer patients should navigate the complicated relationship of diet and cancer.

Q: What unique challenges do cancer patients face when it comes to nutrition?

A: Some cancer patients are victims of misinformation from the internet, clinicians that are not experts in nutrition, or overbearing advice from friends and family. This oftentimes exacerbates disordered eating patterns post-diagnosis. Even when a cancer patient is in remission, people in their life will watch and comment on food choices of survivors. Going through cancer diagnosis and treatment is traumatic –  food insecurities and confusion is part of that.

Another common challenge is that patients want to follow an anti-cancer diet soon after diagnosis. However, cancer prevention nutrition begins only once cancer treatment ends. This includes surgery, chemotherapy, and radiation. For example, red meat is recommended to be limited post treatment to 18 ounces or less per week to reduce risk for colorectal cancer. However, during treatment patients need all the protein they can get. Therefore, patients need to continue eating red meats along with other proteins as much as they can during treatment.

Q: What are misconceptions you often see when it comes to food and cancer?

A: I hear all kinds of misconceptions. One is that sugar feeds cancer. This is false. Eating sugar will not make your cancer worse and limiting it will not improve outcomes. Although research has shown that cancer cells consume more sugar (glucose) than normal cells, no studies have shown that eating sugar will make your cancer worse or that if you stop eating sugar, your cancer will shrink or disappear. However, a high-sugar diet may contribute to excess weight gain, and obesity is associated with an increased risk of developing several types of cancer.

Some people say to avoid soy in order to reduce breast cancer risk. On the contrary, soy doesn’t contain estrogen. Soy contains isoflavones which help reduce risk for breast cancer. This protective effect is less dramatic for women who eat less soy or who start eating soy later in life. Soy contains protein, isoflavones and fiber, all of which provide health benefits.

I’ve also heard that patients should choose all organic. However, there are no significant nutrient differences between organic and non-organic foods.

Q: What positive outcomes can cancer patients see from working with a dietitian?

A: Dietitians are an essential part of the cancer patient treatment. Their job is to apply medical nutrition therapy that focuses on managing symptoms, preventing weight loss and maintaining optimal nutrition status during cancer treatment. Studies demonstrate the value of nutrition interventions from working with a dietitian on functional outcomes including improved tolerance to treatment, reduced treatment breaks, decreased weight loss, confidence in food choices and quicker recovery post treatment.

Q: How does diet play into treatment?

A: During cancer treatment we focus on two main areas: maximizing protein intakes with all meals and maintaining body weight. The presence of cancer induces alterations in protein and amino acid metabolism. Some alterations in protein metabolism for cancer patients could look like increased muscle wasting, increased liver protein synthesis, negative nitrogen balance or other issues. Protein requirements are increased, up to doubling, after a cancer diagnosis and during treatment. Meeting those increased needs will fight back against negative protein metabolism alterations to maintain optimal nutrition status and avoid malnutrition.

Individuals with cancer usually have increased requirements for calories (and protein) due to periods of under-nutrition before or after diagnosis and metabolic effects from the cancer and its treatments. The main goal with cancer patients is to preserve lean body mass during treatment; we can monitor this by making sure the patients do not lose or gain weight. Certain cancers can cause higher energy expenditures. It is critical for patients to work with a dietitian on a weekly basis to see how protein and calories may need to be adjusted during treatment and support the best possible cancer treatment outcomes. Over and underfeeding both have detrimental effects.

Q: What are you a big proponent of when it comes to food and cancer?

A: Reducing food fear after a cancer diagnosis; during treatment and once treatment commences, knowing what the research says and not being fearful when eating related to another cancer diagnosis.

Working with a dietitian who specializes in oncology and understands the science related to cancer and nutrition is also important. Patients can learn the facts and not become overwhelmed with the plethora of misinformation around oncology nutrition.

Learn more about living a cancer fighting lifestyle here.


  1. REPLY
    Melissa says

    I’m so scared that I just ruined everything by eating some chocolate chip cookies several days in a row. I finally felt “normal” instead of being in constant fear of what to eat or not to eat since my cancer but now I’ve had some hot flashes and I feel like I just stirred up some cancer. I went through treatment for breast cancer almost 2 years ago. I’m in constant fear of it returning or spreading. I mostly try to follow a Mediterranean diet but with everything that has been going on lately and being home I’ve indulged a little and now am going down that dark rabbit hole.

    • REPLY
      Tim says

      I’ve recently read that at least some breeds of dogs can sniff out at least some cancers: https://www.sciencedaily.com/releases/2019/04/190408114304.htm#:~:text=Dogs%20have%20smell%20receptors%2010%2C000,with%20almost%2097%20percent%20accuracy.

      Maybe if they can be put to work, trained for that purpose or we can develop a synthetic alternative, it would put a lot of people’s minds at ease.

    • REPLY
      Nichole Giller, RDN says

      Hello Melissa! Thank you so much for your comment. You did not ruin anything! Being in constant fear is not how to live after cancer and it is very hard to avoid that feeling – and comes up so often with my clients – please reach out so we can chat more about your nutrition goals and how to STOP food fears after cancer! It can be done!

      • REPLY
        Paula W Jagemann says

        Nicole, Hoping this finds you well. I am writing an SBIR NCI/NIH grant on Nutrition and the role metal toxicity may play during treatment and UWL. I read your article with interest and wondered if I could vet this idea by you. I’m always looking out for advocates of “in-treatment” nutrition vs. preventative and post. I did run my theory by the former President of NCI, and he’s encouraging me to see it through a human clinical trial. The best part of this story is that I am a serial entrepreneur not an oncology dietician, but, have been in the consumables/OTC side of cancer care for ten years and may just have found one of the primary culprits to UWL, including Cachexia. I loved the article and hope to get 15-20 min of your time. Paula.Jagemann


  2. REPLY
    Fay says

    Hi Nichole, how can I connect with you? I am going through sandwiched treatment 3,chemo + surgery + 3 more chemo for Endometrial cancer. I have switched to plant based diet plus some animal protein (chicken, turkey, fish) and also lentils for protein. Would love your guidance.

  3. REPLY
    Beverly McAnallen says

    Would like help with diet. Have colon cancer and cancer in liver from endometrial cancer diagnosis in 2011. Cancer removed, but now have a 2 by 2 by 1 tumor in colon and a 4 centimeter lesson in liver. Operation to remove will be in about 2 weeks. What dit should I follow?

  4. REPLY
    Rachel Morgan says

    Hi I was diagnosed Oct 2015 bowel had extensive surgery and clear scan. I’m terrified of reoccurrence and terrified of food. My diet so limited. How do I get an appointment. Would be so grateful for some guidance

  5. REPLY
    Judy says

    How do I find a qualified oncology nutritionist in my hometown? My google searches got me here, but not really finding anything local. I read too much and am so happy to see your comment about sugar, my husband is going through enough without me piling on with not-needed changes in his diet. I need help!

  6. REPLY
    Corinne says

    What’s up friends, good piece of writing and pleasant arguments commented at this place, I am
    really enjoying by these.

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