Problems with eating and nutrition are common among people affected by cancer. They may be caused by the cancer itself, cancer treatments, or associated symptoms such as pain, nausea, fatigue or swallowing difficulties. Good nutrition helps maintain strength, improve tolerance to treatment and enhance quality of life.

It is important to inform your healthcare team if you experience:

• Unintentional weight loss.
• Loss of appetite.
• Difficulty eating or drinking.
• Persistent nausea or vomiting.
• Diarrhoea or constipation.
• Pain when swallowing.
• Significant changes in taste or smell.

Early assessment by a registered dietitian can help prevent nutritional complications and improve treatment outcomes.

Mouth Pain and Mucositis

Mucositis is inflammation and ulceration of the lining of the mouth or throat. It may occur during chemotherapy, head and neck radiotherapy, or certain targeted therapies.

Recommendations

• Drink fluids frequently to maintain good hydration.
• Choose soft, moist foods that are easy to swallow.
• Add sauces, broths or olive oil to make swallowing easier.
• Try cold or lukewarm foods if they feel more comfortable.
• Avoid spicy, highly acidic or very salty foods.
• Avoid hard or crunchy foods that may irritate the mouth lining.
• Use a soft-bristled toothbrush.
• Maintain careful oral hygiene.
• Ask about pain relief or specific treatments if oral pain develops.

Changes in Taste and Smell

Some treatments may cause:

• A metallic taste.
• Reduced sense of taste.
• Increased sensitivity to certain smells.
• Changes in food preferences.

What May Help

• Try different foods and reintroduce foods you dislike after a few weeks.
• Use mild herbs and seasonings to enhance flavour.
• Serve foods cold or at room temperature if cooking smells are bothersome.
• Use plastic cutlery if you notice a metallic taste.
• Marinating meat or fish may improve palatability.
• Maintain good oral hygiene before meals.

When You Are Too Tired to Eat

Fatigue can make preparing and eating food more difficult.

Helpful Strategies

• Prepare meals at times of day when you have the most energy.
• Freeze portions for future use.
• Ask family members or carers for help.
• Use healthy prepared meals when necessary.
• Eat small, frequent meals.
• Consider oral nutritional supplements if recommended by your healthcare team.

If You Have Constipation

Constipation may be related to certain treatments, reduced physical activity, dietary changes or medications, particularly opioids.

General Recommendations

• Increase fluid intake unless you have been advised otherwise.
• Stay physically active according to your abilities.
• Eat fibre-rich foods if appropriate for your clinical situation, including:
• Fruit.
• Vegetables.
• Pulses.
• Wholegrain cereals.
• Establish regular toilet routines.

Not all patients should increase fibre intake. People with gastrointestinal cancers, bowel obstruction or certain surgical conditions may require specific dietary advice. Always consult your healthcare team.

If constipation persists, prescribed laxatives may be required.

If You Have Diarrhoea

Diarrhoea may result from:

• Chemotherapy.
• Abdominal or pelvic radiotherapy.
• Immunotherapy.
• Digestive tract surgery.
• Infections or certain medications.

Recommendations

• Drink fluids regularly to prevent dehydration.
• Choose easily digested foods, such as:
• Rice.
• Pasta.
• Potatoes.
• White bread.
• Chicken or fish.
• Eggs.
• Eat small, frequent meals.
• Avoid very fatty or heavily seasoned foods.
• Temporarily reduce foods high in insoluble fibre if they worsen symptoms.

Seek Urgent Medical Advice If:

• You have more than 4 to 6 episodes of watery diarrhoea per day.
• You notice blood in your stool.
• You develop a fever.
• You experience dizziness or signs of dehydration.

Gas and Abdominal Bloating

To help reduce gas:

• Eat slowly and chew food thoroughly.
• Avoid carbonated drinks if they worsen symptoms.
• Limit foods that personally cause excessive gas.
• Take gentle walks after meals.
• Maintain regular physical activity.

Nausea and Vomiting

Nausea can have many causes, and effective treatments are available to prevent and manage it.

Recommendations

• Eat small amounts of food several times a day.
• Avoid allowing your stomach to become completely empty.
• Choose dry or low-fat foods when feeling nauseated.
• Eat cold or lukewarm foods if smells trigger nausea.
• Sit upright during and after meals.
• Sip fluids regularly throughout the day.
• Ginger may be helpful for some patients.

Take anti-sickness (antiemetic) medications exactly as prescribed, even if nausea seems mild.

Loss of Appetite

Loss of appetite (anorexia) is common among people with cancer and may contribute to weight loss and loss of muscle mass.

Recommended Strategies

• Eat small amounts frequently.
• Take advantage of times when your appetite is at its best.
• Enrich foods with energy- and protein-rich ingredients, such as:
• Powdered milk.
• Cheese.
• Greek yoghurt.
• Eggs.
• Olive oil.
• Keep nutritious snacks readily available.
• Remain gently active when possible, as physical activity may help stimulate appetite.
• Use nutritional supplements when recommended.

Important

International guidelines recommend early intervention when reduced food intake or weight loss occurs in order to prevent malnutrition and cancer-associated cachexia.

Increased Appetite

Some treatments, particularly corticosteroids, may increase appetite and contribute to weight gain.

Recommendations

• Maintain regular meal times.
• Prioritise fruit, vegetables, pulses and healthy protein sources.
• Limit ultra-processed foods.
• Pay attention to portion sizes.
• Remain physically active according to your abilities.

When Should You Contact Your Healthcare Team?

Contact your healthcare team if you experience:

• Inability to eat or drink adequately.
• Persistent vomiting.
• Severe diarrhoea.
• Signs of dehydration.
• Pain when swallowing.
• Difficulty swallowing liquids.
• Marked weakness or a significant decline in physical functioning.