Loss of appetite is also known as anorexia. Cancer-associated anorexia is probably due to a combination of physiological changes as well as the psychological impact of the disease. In certain types of cancer, there is an increased basal metabolic rate and increased total energy expenditure. This means that more energy (calories/kilojoules) are required to maintain current weight and lean body mass. This is compounded by a loss of appetite; hence it is easy to see that people with cancer are at risk of developing malnutrition, either as the result of the cancer itself, or the side effects of common cancer treatments such as surgery, chemotherapy, and radiotherapy.
There are several factors that may contribute to the type and degree of malnutrition:

  • The main organ where the malignancy occurs.
  • The stage of the cancer at the time of diagnosis.
  • The symptoms experienced by the person with cancer.
  • The type and frequency of the cancer treatment being used and the side effects associated with that treatment (surgery, radiation, or chemotherapy).
  • The effect of the cancer on food and nutrient ingestion, tolerance, and utilization.

More than half of patients with advanced cancer suffer from anorexia, although no agent is formally indicated to treat that complication. There are currently several ways to manage anorexia, including nutritional support to increase caloric intake and the use of antiemetics to control nausea and vomiting associated with chemotherapy and radiotherapy. In addition, certain medications may help to stimulate appetite and are often used to treat anorexia.

Causes of appetite/weight loss

There are many causes of anorexia or weight loss. Some general causes include:

A loss of 10% or more of body weight is considered significant; however the period over which the weight is lost also needs to be considered, as well as whether it has been intentional or not.


People with cancer frequently require a high-energy (calorie/kilojoule) diet to prevent weight loss. They may also need a diet that is high in protein to prevent muscle wasting. This will require review by a dietitian to determine the best diet. In addition, the side effects of common cancer treatments may also affect whether a patient is getting adequate nutrition. The following are some common problems and suggestions that may be helpful when caring for a patient with cancer.

Loss of appetite (anorexia)

Drugs which increase appetite may be considered in some cases.
Dietary strategies to manage loss of appetite can be discussed with your dietitian. Some strategies are listed below:

  • Try not to miss meals as you may not feel hungry but your body still needs nourishment.
  • Small meals eaten more often may be easier to manage. Try to have something to eat every two or three hours during the day, and serve small food portions.
  • There may be times of the day when you feel more like eating. Eat well during these times.
  • Drink after and between meals. Avoid drinking fluids half and hour before meals and during mealtimes as they tend to fill you up, so that you eat less.
  • Gentle exercise can stimulate your appetite.
  • Enjoy meals as a social occaision – eat with family and friends if possible.
  • Treat yourself to your favourite foods.
  • If you do not feel like preparing a meal, have frozen meals and a range of ready prepared foods and snacks on hand. Cook in advance and re-heat meals to reduce tiredness at meal times.

Chewing and swallowing difficulty

Dietary strategies to manage difficulties chewing and swallowing can be discussed with your dietitian. Some strategies are listed below:

  • Maintain good oral hygiene. Keep your mouth clean with regular mouth washes and gargles.
  • Try changing the texture of foods to make them easier to eat (e.g. mashed or puree food).
  • Avoid extremes of temperature in food and drinks – very hot or very cold.
  • Drink plenty of nourishing fluids (e.g. milk-based drinks).
  • Moisten food with gravy and sauces to make it easier to swallow.
  • If you are having problems with your dentures, have them checked by your dentist. It may help to take them out at meal times and try softer foods which do not need to be chewed.

Nausea and vomiting

Nausea with or without vomiting is a common side effect of surgery, chemotherapy, radiation therapy, and biological therapy. Nausea can prevent you from eating enough food and maintaining your nutritional intake and weight.
Dietary strategies to manage loss of appetite can be discussed with your dietitian. Some strategies are listed below:

  • Discuss anti nausea (antiemetic) medications with your doctor.
  • Avoid eating 1–2 hours before your treatment if this makes nausea worse. Try to ‘catch up’ after treatment.
  • Avoid foods that:
    • are fatty/greasy/fried;
    • are spicy or hot;
    • have strong odours.
  • Eat small amounts more frequently and eat slowly.
  • Eat before you get hungry, because hunger can make feelings of nausea stronger.
  • Avoid eating in a room that is stuffy, too warm, or has cooking odours that might disagree with you.
  • Sip cold clear fluids (e.g. cordial, flat gingerale, lemonade, diluted fruit juices, icy poles and jelly). This is particularly important if you are vomiting to prevent dehydration.
  • Have foods and drinks at room temperature or cooler; hot foods may add to nausea.
  • Rest after meals, because activity may slow digestion. It’s best to rest sitting up for about an hour after meals.
  • Choose stomach-friendly foods, such as toast, crackers, yoghurt, creamed rice, oatmeal, boiled potatoes, rice, noodles, steamed/baked skinned chicken, canned peaches or other soft, bland fruits and vegetables, carbonated drinks that have gone flat.
  • If vomiting persists after a day or two, contact your doctor or treatment centre. Contact them sooner if you feel very unwell.

Taste alterations and aversions

If you suffer with taste alteration and aversions, discuss this with you dietitian. The following dietary strategies may also help:

  • If food has no flavour, try adding salt, garlic, cheese, bacon, herbs, soup powders, chutneys, pickles, spices, sugar and chocolate or other flavourings.
  • If food tastes too sweet, try adding salt, lemon juice, or coffee powder.
  • If food tastes metallic or very salty, extra sugar or honey can disguise the flavour. Try sucking on lemon or other sharp-flavoured boiled lollies.
  • Try marinating meat, fish, chicken or tofu to add flavour.
  • Try using a straw and position it to the back of the mouth to bypass the tastebuds.
  • Sometimes the smell of food can put you off eating. Try cold food or food without a strong smell.
  • If possible, stay out of the kitchen when food is being prepared. Try ready-to-use foods. Ask your family or friends to cook for you.

Keep teeth and mouth clean by brushing and rinsing often. When your mouth is clean and moist, food flavours are more distinct.

Weight loss and muscle wasting

Increase protein and calories in the diet.

  • Eat smaller, but more frequent meals.
  • Add powdered milk to foods and beverages.
  • Drink mainly calorie-containing beverages such as milk-based beverages or commercial nutrition supplement drinks.
  • Add diced meat or cheese to sauces, vegetables, soups, and casseroles.
  • Snack throughout the day on calorie-dense foods such as cheese and crackers, nuts and dried fruits.
  • Increasing fats in the diet is an excellent way to increase energy consumption, if you are tolerating fats. Add margarine or butter to breads and vegetables. Add gravies and sauces to foods in liberal amounts. Use extra oil in cooking and crumb and fry meats, chicken or fish. Use extra mayonnaise and dressing on salads. Add cream and ice cream to desserts.

Objectives for a cancer treatment diet

  • To achieve and/or maintain optimal nutrition status
  • To maximize the benefits of therapy the patient is receiving
  • To reduce symptoms caused by the therapy
  • To prevent or reverse loss of of muscle and fat stores

Role of intravenous and enteral feeding

One frequently asked question is, “Will nasogastric feeding or intravenous feeding help?” At first sight, this might seem like a good idea if a patient is eating poorly; however, as with any intervention, there are potential risks and side effects. It is important to discuss your individual nutritional needs (including the possible need for enteral or intravenous feeding) with your doctor and dietitian.

  • Intravenous feeding: Intravenous feeding involves giving carbohydrates, protein, fats, vitamins and minerals into a vein. There are high infection risks when people are given intravenous feeding for any length of time.
  • Enteral feeding: Enteral feeding involves giving carbohydrates, protein, fats, vitamins and minerals into a tube placed in the nose (leading to the stomach or small intestine), directly in the stomach, or small intestine. Enteral feeding is usually of more benefit to the patient than intravenous feeding; however, where patients cannot be enterally fed, intravenous nutrition will be used.

Examples of times when enteral or intravenous nutrition may be of benefit include immediately after surgery, or sometimes during other anti-cancer treatments such as radiotherapy or chemotherapy. These are times when the body has a tendency to increase the metabolic rate in an effort to get the body to recover more rapidly. In addition, this form of feeding might be helpful in patients with oesophageal cancers, where swallowing food is often difficult.

Article kindly reviewed by:

The DAA WA Oncology Interest Group
Food4Health (Helen Baker Dietitian-APD)

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