Decorative image

Eating and drinking during radiotherapy

You need to have as healthy a diet as possible during radiotherapy. Your body needs protein to heal itself and you need plenty of calories.

What to eat and drink

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. 

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 done again.

It is important to eat high energy and protein foods if you are able to eat normal 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 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, about 3 litres a day if possible. Keeping well hydrated helps the body to heal the radiotherapy damage.

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 strong alcohol – it can aggravate a sore mouth or a sensitive digestion
  • avoid spicy foods if your mouth or throat are sore
  • ask staff about potential problems and how to try to prevent them before you start your treatment if possible
  • tell the radiotherapy staff about any problems you have with eating or drinking – they can arrange for you to talk to a dietician
  • ask the staff if you need any food supplements

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 staff involved in your treatment.

Alcohol during radiotherapy

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

Radiotherapy can make you feel tired and alcohol can make you feel even more tired. 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.

Last reviewed: 
14 Mar 2016
  • External Beam Therapy
    Peter Hoskin
    OUP Oxford, 30 Aug 2012

  • De Vita, Hellman, and Rosenberg's Cancer: Principles and Practice of Oncology (9th edition)
    De Vita, V.T., Lawrence, T.S. and Rosenberg S.A.
    Lippincott, Williams and Wilkins, 2011

Information and help

Dangoor sponsorship

About Cancer generously supported by Dangoor Education since 2010.