Weight loss

Radiotherapy to your head and neck area can make you lose weight because you might have: 

  • a sore or dry mouth
  • a poor appetite
  • taste changes due to treatment
  • difficulty swallowing due to soreness or swelling in your throat

These effects might be temporary and gradually go back to normal after treatment ends. But for some people, the effects may be permanent. There are things you can do to help keep your weight up. 

Why it's important to maintain your weight

Your radiotherapy team plan your treatment using scans of you that were taken before your treatment began. They plan it very precisely using your body measurements. This means if you lose or gain weight during radiotherapy it can change the amount of radiation that the cancer or nearby healthy cells receive. 

Because of this, it is important that your weight stays around what it was when you had your planning scan. If you lose too much weight, your radiographers will work out the effect that this may have on your planned treatment and see if you need another planning scan. 

Losing too much weight might also make you feel weaker.

Coping with weight loss

It's important to eat and drink as well as you can during your radiotherapy. Your side effects aren't likely to start for a week or so, which means for as long as you feel well try to eat your normal diet. 

You might see a dietitian once a week during your treatment. They can help to advise you on foods that are easier to eat. They can also prescribe or get your doctor to prescribe nutritional supplements, such as high calorie drinks to help keep your weight up. Remember to drink plenty of other fluids too. 

Your doctor might also prescribe strong painkillers if your throat is very sore and eating and drinking is painful.

Try not to drink alcohol (especially spirits) or smoke because this can make your mouth and throat very sore.

If eating becomes very difficult you might have:

  • liquid feed through a drip into a vein or a tube down your nose to your stomach
  • a feeding tube put into your stomach through the skin (called a percutaneous endoscopic gastrostomy or PEG tube)

Some hospitals might arrange for you to have a feeding tube before you start radiotherapy - this is to stop you from losing too much weight. This varies from hospital to hospital. 

Last reviewed: 
10 Nov 2020
Next review due: 
10 Nov 2023
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