Nutrition and Healthy Eating for Cancer Patients

Healthy eating is important for all cancer patients as they require sufficient energy intake to maintain current body weight, and prevent drastic weight loss.

Nutrition and Healthy Eating for Cancer Patients

Patients affected with cancer have high nutrient requirements due to increased metabolic rate. Tumour-induced changes alter the way our bodies need nutrients and how it absorbs different nutrients. When a patient is diagnosed with cancer, many develop taste changes and poor appetite that adversely influences their food intake. As a result, many patients are either severely underweight or experience some form of malnutrition. Between 20% - 80% of cancer patients suffer from malnutrition.

Healthy eating is important for all cancer patients as they require sufficient energy intake, to maintain current body weight, and prevent drastic weight loss. Eating high fibre food from wholegrains, fruits and vegetables are recommended (if not contraindicated). Also, sufficient lean protein and healthy fats from various food sources are keys to a balanced and healthy diet.

Healthy preparation methods to follow:

  • Stir fry
  • Grill
  • Boil
  • Broil
  • Roast
  • Steam
  • Poach

Myth vs Fact

"Red meat increases the risk of cancer"

Consumption of red meat increases the risk of cancer, especially colorectal cancer. Red meat contains compounds that have been shown to damage the lining of the gut and possibly promote cancer. While white meat (fish and poultry) is not associated with colorectal cancer risk and is recommended as an option to replace red meat. Cooking red meat at high temperatures can also produce other cancer-causing compounds, especially grilling, pan- frying and barbecuing for a long period. So, the best is to consume below 500g of red meat a week or approximately 70g per day without raising cancer risk.

"Go Organic is better"

Studies have yet to prove the correlation between consuming organic food and cancer, whether in prevention or delaying cancer. There is no evidence of a difference in nutrient quality between organically and conventionally produced food.

"Processed food causes the risk of cancer"

Processed meat includes hot dogs, ham, bacon, sausage, and some deli meats. It refers to meat that has been treated in some way to preserve it or flavouring that includes salting, curing, fermenting, and smoking. Sodium Nitrate and Sodium Nitrite are used as preservatives to add colour and flavour to processed meats. The International Agency for the Research of Cancer (IARC) has reviewed ingested nitrates and nitrites and classified them as probably carcinogenic (cancer causing) to humans.

Every 50g portion of processed meat eaten daily increases the risk of colorectal cancer by about 18%. Besides processed meat, it is also recommended to reduce canned food, salted fish, egg or vegetables. Get more food from fresh sources. It is recommended to minimise overall intake of processed food or avoid it at all.

"Cook food using microwave ovens increases risk of cancer"

Microwave ovens use microwave electromagnetic energy to heat or cook food. Water molecules within the food are vibrated by the microwaves and produce heat, which cooks the food. Microwave ovens do not make foods radioactive. Having said this, it is important the instructions for use for a microwave oven. For example using microwave-safe containers only. Heating your food in plastic containers or with plastic wrap that is not labelled as microwave safe may cause the chemicals in the plastic to break down and contaminate food it holds. It is these chemicals that show possible cancer-causing features.

"Sugar feeds cancer?"

Sugar is naturally found in fruits, vegetables, grains and dairy products. It is also added to foods to make them sweeter, such as soft drinks and desserts. All cells, cancerous or not, use sugar for energy. Because cancer cells can grow fast, they use a lot of sugar. However, eating food with sugar does not make cancer cells grow faster nor does depriving your body of sugar slow down the cancer growth. If you avoid sugar in your diet, your body will make sugar from your body’s muscle and fat stores. This is unhealthy as your cells can also starve from important nutrients from the avoided food. Our recommendation is to reduce simple sugar intake and should choose more wholesome, wholegrains, fresh fruits, vegetables and low fat dairy products.

"Alkaline in blood can kill cancer"

Our blood is slightly alkaline, with a pH between 7.35 and 7.45. This is tightly regulated by the kidney and respiratory system. Because of the body’s natural regulatory mechanisms to keep the blood pH level constant, a selectively alkaline diet has not been shown to elicit a sustained change in blood pH levels, at most, change the blood pH minimally and transiently. Only the urine may have a variable pH from acid to alkaline depending on the need for balancing the internal environment. Even though there are no clinical trials on benefits of alkaline diet, it is still considered a healthy choice as it encourages more plant based food that provides protective nutrients, phytochemicals and fibre.

Lifestyle habits to keep cancer at bay

  • No smoking
  • Limit alcohol
  • Keep healthy body weight
  • Maintain a healthy diet which includes choosing plant-based food, limit red meat and limit/avoid processed food
  • Be physically active daily for 30 minutes or more

Recommended diet for cancer patients

During cancer treatment, your body often needs more calories and protein to help maintain your weight, keep up your strength, rebuild your tissues and support your recovery after surgery. People who eat well are able to cope with side effects of treatment better, and may even be able to handle higher doses of certain drugs.

Examples of high energy food:

  • Healthy oil and fats such as olive oil, avocado, nut spreads
  • Honey, fruit juices, dates, dried fruits
  • Full cream dairy products
  • Nuts and seeds
  • Cream, chocolate, sweets, cakes, muffins, ice cream
  • Oral nutrition supplements

High protein foods include:

  • Meat, fish, chicken, egg
  • Dairy products such as milk, cheese, yogurt
  • Beans, legumes, soy bean curd, soy milk
  • Nuts and seeds
  • Oral nutritional supplements

Different cancer treatments can cause different kind of side effects that may make it hard to eat or drink. Not everyone experiences nutrition-related side effects during cancer treatment.


If you do experience any nutrition problems, here are some tips on how to manage these issues.

Nausea and Vomiting

  • Eat five to six meals and snack daily.
  • Drink less liquid in a meal.
  • Choose easy to digest, light or low-fat food.
  • Snack on: dried crackers, fresh fruits, nuts and seeds.

Reduced Appetite

  • Increase nutrient density of food and beverage. Examples are honey in water, chocolate powder with skim milk powder, soup with soy bean curd cubes, porridge with sesame oil.
  • Choose high protein high energy nutritional drinks. Dietitian may assist you to make the right options.
  • Keep snacks for nibbling throughout the day.
  • Eat your largest meal when you have the biggest appetite.

Soreness of Mouth, Throat and Tongue

  • Sip clear, cold, non-acidic liquids such as cold drink, honey, popsicle, chrysanthemum tea or melon juices.
  • Choose smooth, soft and moist food like cream soup, mashed potato, porridge, pudding, ice-cream and soup noodles.
  • Avoid spicy food.
  • Avoid foods with extreme temperature.

Taste Change

  • Adjust seasoning and spices in cooking for the taste you desire.
  • Replace food with unpleasant smell/taste with milder choices.
  • Eat dried or fresh tangy fruit, lemon drops or mints.

Early Satiety

  • Eat protein dishes first when eating your meals.
  • Eat nutrient dense, small frequent meals.
  • Limit fluid consumption during meals.
  • Take easily digestible foods such as porridge or soupy noodles.
  • Eat slowly and chew all foods thoroughly.


  • Drink 6 to 8 glasses of fluid in a day.
  • Avoid lactose containing foods such as milk products.
  • Choose low fat diet.

Other Diets (Low Iodine Diet)

The purpose of this diet is to deplete the body stores of iodine and increase the effectiveness of the radioactive iodine (RAI) therapy. This diet is designed as a temporary measure and usually need to be followed for 1 or 2 weeks prior, during and about 3 days after the RAI therapy.

How much iodine should you take for low iodine diet?

The goal of a low iodine diet is to limit intake of iodine to less than 50mcg of iodine per day. To achieve this, you need to avoid iodised salt and sea salt, all fish and seafood, milk and dairy products, soy and soy products, processed foods like canned, packaged or frozen foods, commercially prepared bakery products, spice mixtures and seasoning packets. Talk to your dietitian to find out more on how to incorporate low iodine diet into your daily meal plan.

After cancer treatment

Eat a balanced diet. Vary your diet to include lots of fruits, vegetables, wholegrains, lean protein and healthy fats. This combination of foods will ensure that you get vitamins and nutrients to help make your body strong.

If you are concerned about eating with cancer, talk to your dietitian for more personalised dietary information.