Eating and drinking

Having radiotherapy treatment can affect your eating and drinking habits. This is most likely for radiotherapy treatment to the head and neck. It can cause a sore or dry mouth, difficulty swallowing and taste changes. You may also lose your appetite. All of these side effects can affect how you feel about eating and drinking. 

There are things you can do to help overcome this. You can also follow advice to help the symptoms from becoming worse. 

Who you see on treatment

Your radiographer, doctor or nurse can advise you on how to eat well. They can also arrange for you to see a dietitian if you are having problems with eating. You usually see a dietitian weekly if you're having head and neck radiotherapy.

It is important not to diet during radiotherapy so that you don't lose weight. Your radiotherapy plan is specific to your size and shape. If your weight changes a lot, your radiotherapy plan may need to be planned again. 

Which foods can help

If you're struggling to eat your usual foods you can try high energy and high protein foods. These include:

  • meat

  • fish

  • eggs

  • cheese

  • full fat milk

  • pulses (peas and beans)

If you don't have much appetite you can add extra energy and protein to your diet, without actually having to eat more food. You can have high energy drinks such as milkshakes or soups. And you can add high protein powders to your normal food. Your doctor or nurse can prescribe these for you.

It is important to drink plenty of fluids, at least 2 litres a day if possible.

Tips for eating well

You could try some of the following tips if you are having trouble eating:

  • Have small snacks through the day rather than large meals – eat little and often.

  • Have a soft or liquid diet if swallowing is difficult.

  • Avoid alcohol – it can make a sore mouth or sensitive digestion worse.

  • Avoid spicy foods if your mouth or throat are sore.

  • Ask your radiotherapy team about potential problems and how to try to prevent them. before you start your treatment if possible.

  • Tell your radiotherapy team about any problems you have with eating or drinking – they can arrange for you to talk to a dietitian.

  • Ask your radiotherapy team or dietitian if you need any food supplements.

  • Avoid foods that make you gassy or constipated if you're having pelvic radiotherapy.

What to do if you have problems

Focus on eating high fat foods if you are having difficulty eating enough. There are more calories in fat than in protein or carbohydrate. 

Remember that you might lose a little weight during radiotherapy. But if you are having any problems with eating tell the team involved in your treatment. If you are having radiotherapy to the head or neck you may need to have a tube put into your stomach. You may have liquid food put through the tube for some time.

Alcohol during radiotherapy

Usually it is fine to have small or moderate amounts of alcohol during your treatment. But alcohol can inflame a sore mouth or throat if you are having radiotherapy to your head or neck area. It can also irritate your bladder if you are having pelvic radiotherapy.

Radiotherapy can make you feel tired and alcohol can make this worse. It is important not to drive or operate machinery if you feel tired or dizzy.

Ask your doctor or radiographer if you are not sure whether you can drink alcohol.

Worries about treatment side effects

You may feel anxious about radiotherapy side effects and this is normal. It can help to talk through any worries you have with your doctor, nurse or radiographer.

  • External Beam Therapy (Radiotherapy in Practice) Third Edition
    Peter Hoskin
    Oxford University Press, 2019

  • Devita, Hellman and Rosenberg's Cancer: Principles and Practice of Oncology (12th edition)
    VT Devita, TS Lawrence and SA Rosenberg
    Wolters Kluwer Health, 2023

Last reviewed: 
20 Mar 2024
Next review due: 
20 Mar 2027

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