Cancer and Nutrition: The Latest Guidelines
As a health and exercise professional, answering your clients’ basic nutrition questions is an everyday component of delivering quality support. If you work with clients who are cancer survivors, whether they are currently undergoing treatment or have been cancer-free for some time, the need and desire for quality, evidence-based and real-world nutrition strategies is even more significant. Survivors have even more nutrition-related questions due to concerns about how diet can impact survival and recurrence. Additionally, cancer survivors report that they don’t receive enough nutritional guidance from their healthcare team, which prompts them to seek information from other sources.
If you are working with someone who has been impacted by cancer (or who is at high risk for cancer), the newest guidelines published in 2022 are a vital resource to follow. The American Cancer Society (ACS) and the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) recently updated their nutrition guidance. While the ACS guidelines focus on all individuals after a diagnosis of cancer, the WCRF/AICR guidelines also emphasize prevention and reiterate the safety and efficacy of these guidelines for reducing survivors’ risk of recurrence. New guidelines from the American Society of Clinical Oncology (ASCO) for individuals undergoing treatment for curative stage cancer (stages 1–3) were also recently developed and are included for reference.
In brief, the guidelines from the ACS and ASCO suggest that the Mediterranean diet is an excellent evidence-based, plant-forward, foundational diet because it emphasizes minimally processed foods, lean proteins and a foundation of good fats such as olive oil and avocado. Additionally, the Mediterranean diet suggests that red meats, sweets and alcohol be consumed sparingly, once weekly or less.
Table 1 summarizes the three sets of guidelines. The purpose of this article is to not only provide a broad overview of the latest guidelines, but also to help you better serve your clients by understanding how best to guide them in making nutrition choices that can bolster their health, whether they are trying to prevent cancer, enhance their health during treatment or reduce their chances of recurrence. Armed with this knowledge, your clients can make informed decisions about their diets that can profoundly impact their overall health and well-being.
Table 1. Summary of Nutrition Guidelines for Cancer Survivors
American Cancer Society (ACS) (2022)
American Society of Clinical Oncology (Guidelines for Patients During Curative-intent Treatment)
Eat a healthy diet with adequate macronutrients from both animal and plant-based sources. Strive for a plant-forward diet utilizing as many whole foods as possible.
Limit red and processed meats, sugar-sweetened beverages, highly processed foods and refined grains.
Avoid or minimize intake of alcohol.
Follow ACS guidelines, with specific evidence recommendations related to the benefits of fiber and soy in a regular diet pattern.
These guidelines underscore the importance of maintaining a healthy body composition to reduce the likelihood of recurrence (as well as for prevention).
Clinical question: Does consuming a particular dietary pattern or food(s) during cancer treatment safely improve outcomes related to quality of life, treatment tolerance or cancer control?
Recommendation: There is currently insufficient evidence to recommend for or against dietary interventions such as ketogenic or low-carbohydrate diets, low-fat diets, functional foods or fasting to improve outcomes related to quality of life, treatment toxicity or cancer control.
Neutropenic diets are not recommended to prevent infection in cancer patients during active treatment.
Be cautious of overuse or misuse of micronutrient supplementation such as herbs, vitamins and minerals, especially during treatment.
With the exception of protein supplementation, there is limited research on the efficacy of supplements after cancer treatment. Individuals are encouraged to read labels on protein snacks and bars due to the ingredients and nutrients these products often contain. More information about individual supplements can be found here.
Do not rely on supplementation to prevent cancer. Cancer survivors are urged to follow prevention guidelines, which include being cautious about supplements, to reduce risk of recurrence. This does not include protein supplements or the use of greens powders.
Supplementation is not recommended during treatment
These guidelines recommend individuals follow the Healthy Eating Index or Mediterranean dietary patterns.
Follow ACS guidelines.
Follow recommendations from a clinical oncology dietitian and the ACS guidelines.
What Do You Focus on First?
When implementing nutrition recommendations, start with an emphasis on nutrition to support healing and recovery, followed by a goal to support muscle hypertrophy and, finally, body composition or weight-related goals.
While a cancer diagnosis and treatments such as chemotherapy are specific to where the mutation originated, such as breast, colon and lung, side effects will impact the entire body. Changes that result in reduced exercise, inactivity, stress, poor sleep and a decline in nutrition quality all slow down overall healing and recovery.
The next goal is to support one of the critical components of a cancer survivor’s fitness program to gain lean body mass through hypertrophy goals. Cancer survivors experience a rapid loss of lean muscle mass and fat gain compared to the general population. In fact, recent research has shown that for many cancer types, what would be an average 10-year loss of lean muscle and related changes will actually occur in the first year after a diagnosis. This loss of lean body mass contributes to reported concerns in this population, such as fatigue or pain. It is also an essential factor in other comorbidities, such as diabetes, and the risk of other chronic diseases.
Nutrition strategies should include adequate dietary protein combined with a strength-training regimen. In addition to muscle hypertrophy–focused exercise strategies, take note of the protein recommendations in the specific topics section below.
Finally, caloric balance and a moderate reduction in caloric intake while maintaining a balanced Mediterranean diet should be the next key focus. In addition to individual concerns about body composition, cancer survivors are at a higher risk of comorbidities related to obesity, including diabetes and cardiovascular disease, which are actually more likely causes of death than cancer.
The Importance of Nutrition
For cancer survivors, the value of nutrition is much broader than counting protein grams, avoiding red meat or improving the gut microbiome. Nutrition strategies can be compared to exercise programming in that a whole-body, holistic approach is required. Many survivors may have been given less-than-helpful dietary advice at some point after their diagnosis. Often, this guidance is acutely focused on symptom management such as taste changes or diarrhea. For survivors, shifting their focus to a broader goal, such as increasing energy or simply feeling better, is likely a common reason they will seek your guidance.
It is essential to recognize that clients often lack quality in their diet, which is one of the critical goals for implementing the recommendations. Cancer survivors are frequently encouraged to “eat anything you want” to maintain weight during treatments. This baseless guidance is primarily due to concerns that unexplained weight loss can be a sign of disease progression. However, many survivors are happy with weight loss during treatment, although they are likely unaware of the implication of muscle loss, and often report a desire to lose weight for other health-related reasons.
The ASCO guidelines clearly state that there is no current recommendation for weight management during treatment due to a lack of evidence. However, that doesn’t mean weight management or mitigating fat gain at any point after diagnosis is unimportant. Rather, this is an opportunity for health and exercise professionals to help their clients move toward greater overall health.
The Essential Role of Health and Exercise Professionals
It is important to note that these guidelines present nutrition and exercise as combined lifestyle strategies to manage short-term side effects, improve the likelihood of survival and reduce comorbidities. Researchers studying this vital combination have produced a wealth of outcomes-based research on the impact of nutrition and exercise on survival. This emphasis on a combined lifestyle program has highlighted the need for qualified health and exercise professionals who can help these individuals implement the recommended lifestyle-based strategies.
According to new research, a healthy diet and regular exercise can independently reduce an individual’s overall risk of death. However, the most significant impact, including significant risk reduction of dying from cancer and other chronic diseases, comes from combining the two.
Specific Nutrition Recommendations
In addition to the general guideline overview, some specific areas deserve special attention, including protein, ketogenic diets, alcohol, soy and sugar.
Dietary protein is vital for cancer survivors. Historically, protein recommendations have been based on the desire to avoid malnutrition. However, newer research suggests that higher intake amounts are not only safe but effective in conjunction with an exercise regimen.
To prevent muscle wasting during cancer treatment, clients should aim to consume at least 1.2 to 1.4 grams of protein per kilogram of body weight. This is considered a good baseline, and intake should emphasize lean poultry, fish and other protein sources, including plant-based foods. If you are working with a client in active treatment, it’s a good idea to collaborate with a dietitian.
The ketogenic diet has become increasingly popular as an obesity-management strategy, and some research studies suggest that it may be used as an adjuvant to specific cancer types such as glioblastoma, a type of brain cancer with a poor prognosis. While some individuals experience benefits in body composition and other metabolic markers such as fasting insulin with a low-carbohydrate diet, clinical evidence to make general recommendations is lacking.
If you are working with a client who wants to follow a low-carbohydrate approach, a whole-foods approach with an emphasis on olive oil, avocados and nuts is the healthiest version of a ketogenic diet. There are some concerns about meeting muscle-hypertrophy goals and supporting healing after treatments with low protein intake, but this strategy may be considered as part of a shorter-term plan with a specific client.
It is recommended to avoid or consume alcohol only occasionally, preferably red wine. The most recent ACS guidelines recommend limiting intake to no more than two drinks per day for men and one drink per day for women. However, alcohol contributes negatively to other lifestyle challenges such as sleep disturbance, mood changes and weight gain.
Previous recommendations stated that soy foods increase the risk of breast cancer and should be avoided for breast cancer survivors. Early studies were completed in mouse models, which made this recommendation challenging to translate to humans.
Newer research that focused on Asian breast cancer survivors found a higher incidence of recurrence when consuming a standard American or western diet rather than a traditional Asian diet in which soy is a typical daily staple. The researchers concluded that eating a moderate amount of soy does not increase the risk of breast cancer or other types of cancer. A moderate amount is considered one to two servings a day of whole-soy foods, such as tofu, soy milk and edamame.
The connection between sugar and cancer is generally confusing, which has also likely influenced the increased use of the ketogenic diet. It is essential to understand that sugar does not explicitly feed cancer cells, but that cancer cells are highly active, which correlates to their need for glucose.
To date, there are no randomized controlled trials showing sugar causes cancer. There is, however, an indirect link between sugar and cancer. Eating high-sugar foods such as cakes, cookies and sweetened beverages can contribute to excess caloric intake. These habits lead to weight gain and excess body fat, a risk factor for 13 types of cancer. In addition, newer research shows that sugar-sweetened beverages, including soda, tea, many smoothies and coffee drinks, increase the incidence of some cancer types, including colorectal cancer in young adults, especially women. These risks and related research should be discussed with your clients.
How to Use the ACE Mover MethodTM to Talk to Your Clients About Nutrition
The ACE Mover Method approach guides you in utilizing your coaching skills to help build rapport and position the client as an active partner in their behavior-change journey. When you use the ACE ABC ApproachTM, which involves asking open-ended questions, breaking down barriers and collaborating on the next steps, each client interaction becomes an opportunity to help clients identify and make progress toward their goals.
Begin by asking your clients about their short- and long-term goals related to embarking on a program of combined fitness and nutrition. Strive to help them identify goals that can be specific and outcomes-based, such as improving energy or function as measured by ability or a specific movement. Identify and inquire about barriers such as nutrition-related fears about specific foods such as soy, animal-based foods or sugar, and don’t forget to examine other barriers, such as budget or time constraints. Collaborate to determine a starting place and ongoing check-ins for your client.
Mark is a 54-year-old man who has recently completed treatment for early-stage colon cancer. He is coming to you for guidance on making positive lifestyle changes to reduce his risk of the cancer returning. His treatment included surgery, intravenous chemotherapy and immunotherapy. He completed all his treatments almost three months ago and recently had a scan that showed no evidence of disease, but he continues to struggle with fatigue. He has a history of hypertension managed by medicine, and he states that his primary care physician told him he has borderline diabetes.
Even before his diagnosis, Mark was largely inactive. His work is computer focused, and he reports taking fewer than 4,000 steps per day. Although he has not exercised regularly for many years, he previously enjoyed weight training. Mark lost about 10 pounds (4.5 kg) during treatment, which he has since regained, mostly in his “mid-section.” His current weight is 215 pounds (97.5 kg), but he would like to reach about 175 pounds (79.4 kg). He is, however, more concerned with his body composition and feeling better.
Mark enjoys eating red meat and some fruits and vegetables, but has been eating more grab-and-go food since his diagnosis and his diet is heavier on starches. He is open to making changes and does enjoy cooking when he has the energy. He says he has trouble sleeping and reports being on his cellphone in bed. He tends to play games or read online, which keeps him up later than he intends to be most nights.
Health and Exercise Professional (HEP): Hi Mark! It is great to meet you. I appreciate you arriving to our scheduled appointment on time. What are you hoping to accomplish by working with me and what physical activities have you enjoyed in the past?
Mark: It is nice to meet you also and I am looking forward to working with you. Currently, I don't do any physical activity and I haven't exercised regularly for many years, but when I did exercise I enjoyed lifting weights. The main things I want to accomplish are to feel less fatigued, have more energy, improve my body composition, lose weight and prevent diabetes.
HEP: Mark, I am excited to be working with you and appreciate all the information you have shared with me so far. Making consistent lifestyle changes in your diet and exercise may help improve all the aspects of your life that you mentioned wanting to focus on.. I am thrilled you have enjoyed strength training in the past because participating in this activity will help to rebuild any muscle mass that has been lost. If you would like, we can gradually begin adding resistance training into your exercise regimen. Becoming more physically active may also help to improve your overall energy levels, which may make it easier to exercise more and maybe even give you enough energy to cook more often.
Mark is agreeable and says that the idea of using exercise to meet his goals is very exciting and he would like to start training with you right away.
HEP: Your excitement is contagious, Mark, and I can’t wait for us to start working together. You mentioned being physically active previously and I wonder what barriers or obstacles to participation you may have experienced at that time and what barriers you think you may experience now?
Mark: Great question. Previously, the main barrier I had was not having a structured program to follow. I never knew what I should be doing and for how long and how often. At first, I was just excited to get started, but overtime I lost my motivation because I wasn't sure if I was doing things right and I didn't have a specific target I was trying to reach. I think I will face the same challenges now. On top of that, I have this fatigue and lack of energy to deal with.
HEP: It sounds like you are saying that having a specific exercise program to follow will make things easier for you and that you would like some instruction on how to perform certain exercises properly. In addition, you could really benefit from having specific goals to reach. Am I understanding you correctly?
Mark: Yes. We are on the same page.
HEP: Great! All the things you mentioned as being potential barriers to your success are things we can work on together. This is your journey, but I will be here to support you along the way. What else might you like to work on?
Mark: Well, I have tried following set diet plans in the past and have never been able to stick with an eating plan for more than a few weeks. I am hoping you can just tell me what to eat, when to eat, how much to eat, and what not to eat.
HEP: Mark, I understand that you want me to tell you what to eat, but providing specific meal plans is not within my scope of practice. However, what we can do is focus on nutrition strategies that will be sustainable long-term no matter where you are eating. We can work together to make sure you have all of he information needed to make consistent and healthy choices to reach your goals no matter where you are in your day or week, or even if you are traveling. How does that sound to you?
Mark: That sounds fantastic! I like the idea of having specific strategies I can use to eat better no matter where I am or what I am doing
HEP: What do you already know about nutrition for cancer survivors?
Mark: To be honest, I don’t know much about how I should be eating. I did receive some initial information from my doctor, but I could honestly use a little more guidance.
HEP: What do you know about the Mediterranean eating plan?
Mark: I have heard of the Mediterranean diet, but I am not sure what it is. If I remember correctly, it is a diet recommended for people with cancer. Can you tell me more about it?
HEP: Yes, you are correct. It is a recommended eating plan.
Next, you introduce Mark to the Mediterranean eating plan and explain what foods are included. You ask Mark to circle the foods he is most likely to eat, and then underline the ones he is willing to try or that are more readily accessible. Lastly, identify times during the week when Mark can enjoy a moderate amount of red meat and a beer.
HEP: Mark, what do you think about this list of foods? Does it look like you have a lot of options to choose from? Do you have anything at home right now that you can easily prepare for dinner? What about tomorrow for breakfast and lunch? In the weeks to come, if you would like, you can focus on choosing foods from this list to add to your diet. Does all this information make sense to you?
Mark: Yes. I really like having a list of foods to choose from and to keep me on track with making healthy choices.
HEP: We have covered a lot of information today and I wonder what specific steps you might want to take moving forward?
Mark: Starting as soon as possible, I would like to start working with you twice per week to perform weight training. I would also like to make sure that at least half of the foods I eat each day are found on the Mediterranean foods list you gave me.
After one week, you meet with Mark again, and he says that he has been able to stick to the foods included in the Mediterranean diet for most of his meals. Additionally, he reports including foods that were not on the list in only three meals, and he made these choices because he felt extra hungry. One evening, he felt more stressed than usual, so he replaced his Greek yogurt with ice cream. Mark reports that not only has making these changes been easier than he expected, but he also feels less bloated in his abdomen and is already feeling more energetic. In addition, Mark was able to schedule and attend the two personal-training sessions with you.
There is currently a significant need for health and exercise professionals who can offer both exercise programming and evidence-based nutrition information to individuals impacted by cancer. Take the time to acquire a foundational understanding of how physical activity and nutrition can impact the health and well-being of this population and you will be meeting an essential need and ultimately help to improve the quality of life for those you serve.
While it is outside the scope of practice for exercise professionals and health coaches to supply, sell, prescribe or recommend nutritional supplements to clients, it is important for professionals to be able to discuss supplementation with clients and to provide education without telling a person what they should or should not be eating. The information shared in this video is helpful for providing education to your clients so they can make their own informed decisions about what they should and should not be eating.