If you have been diagnosed with a brain tumour, a balanced diet could help you keep your strength and energy up, lower your risk of infection and help you recover well from treatment.

What constitutes a healthy diet?

The Department of Health has created the 'eatwell' plate to show what kinds of food make up a balanced diet, and in what proportions they need to be eaten.

Starchy carbohydrate foods

It is recommended that starchy carbohydrate foods ideally form about a third of your diet. They include foods such as cereals, bread, pasta, potatoes, rice, plantain and yam. Carbohydrates are the body's primary energy source. This is because it is faster and easier for the body to convert carbohydrate-rich food into energy than any other type of food.

Try including many wholemeal / wholegrain varieties of carbohydrate foods, such as brown rice, brown bread or brown pasta. The advantages of choosing these types of carbohydrate is that they are higher in fibre, keep you fuller for longer and help you maintain more sustained and balanced energy levels.

Fruits and vegetables

Aim for fruits and vegetables also forming about a third of your diet. It is generally advised that you eat five portions of fruit and vegetables a day, as part of a healthy diet. Fruits and vegetables are an excellent source of vitamins, minerals and fibre.

Protein rich foods

It is advisable that you try to include 2-3 portions of protein rich food a day. Good sources of protein include fish, poultry, eggs, dairy products, nuts and nut butters, and pulses. Dairy products (covered in the next section) are also a good source of protein.

Protein molecules are often referred to as the building blocks of the body. Using protein, the body performs vital functions such as growth and repair of tissue, and maintenance of the immune system.

A lack of protein in the diet can result in slower recovery and an increased risk of infection. Including protein in your diet, therefore, could be especially beneficial if you've had surgery, chemotherapy, or radiotherapy as it can support the body's healing process.

Milk and dairy foods

Also ideally aim for 2-3 portions of dairy and/or dairy alternatives a day. Examples of foods within this food group include milk, cheese, yoghurts and alternatives such as soya milk (fortified with calcium). A portion is equivalent to a pot of yoghurt, small matchbox size of cheese or a glass of milk (approximately 200ml).

Dairy foods are an excellent source of calcium, which is essential for good bone health.

Foods high in fat and / or sugar

The last food group on the 'eat well' plate is foods high in fat / sugar. It is generally advised that as part of a healthy diet, these foods are only consumed in real moderation.

However, these foods can be useful if you are losing weight, have a poor appetite or you are struggling to maintain an adequate intake.

Good and bad fats

Fats are the richest energy source available, which means that every gram of fat has more calories than a gram of protein or carbohydrate. For this reason if you are seeking to put on weight, eating fat-rich food can help, while if you are overweight you might be advised to cut down on the amount of fat-rich food you consume.

There are some types of fat which are considered better than others due to the different effects they may have on cholesterol. Cholesterol is a substance in our body which supports various vital functions such as digestion and the production of hormones.

There are two types of cholesterol, one which is considered good because it lowers the risk of coronary heart disease (blocking of blood vessels and arteries) and one which is considered 'bad' because it raises the risk of coronary heart disease. 'Monounsaturated' or 'polyunsaturated' fats are healthier than those containing 'saturated' fat or 'trans-fatty acids' in terms of keeping levels of 'bad' cholesterol down.

You can find the amount of different types of fats contained in your food by referring to the food label on the packaging.

Sources containing the greatest concentration of monounsaturated or polyunsaturated fats are vegetable oils, nut oils and some types of fish.

Saturated fat is contained mainly in fatty meat and in high fat dairy products.

Trans-fatty acids, in the form of 'partially hydrogenated' vegetable oil, are contained in heavily processed snack foods and some baked goods.


The importance of staying hydrated cannot be stressed enough. Depending on your age and gender, water can make up 50-75% of your body mass. Water underpins every bodily function on every level and so the water we get through food and drink is, like the air we breathe, vital to our survival and wellbeing.

It is generally advised that you drink about eight 8-10 glasses of liquid each day (approximately two litres).

If you have diarrhoea or vomiting as a side-effect of treatment, then it is even more important that you replenish the fluid and minerals lost, by drinking more liquid than you would normally do. Your medical team can supply you with special rehydration drinks in such cases.

If you are having treatment in the form of chemotherapy or radiotherapy, getting plenty of fluids may also aid your body's ability to recover faster by expelling excess toxins.

Apart from the contents of the eatwell plate it is very important to remember to drink enough fluids (at least 8-10 glasses).

What to eat when recovering from treatment

Below is a list of diet-related side-effects of cancer treatments and some common suggestions on how to manage these side-effects.

Too tired to eat

If you are too tired to cook or eat you could:

  • try having six smaller meals per day rather than three larger ones.
  • use snacks, ready made meals and puddings to reduce the burden of cooking.
  • ask friends or family members to cook dishes in bulk and freeze portions so you can have them ready to defrost whenever you need to.
  • ask your doctor or dietitian to recommend nutritious food supplements such as shakes

Feeling sick

Chemotherapy or radiotherapy can cause nausea as a side-effect. Your doctor can give you anti-emetic medication which can help you manage this. If you are having trouble eating because of nausea, you can try to:

  • eat smaller meals more often, rather than large meals further apart
  • eat dry foods, like crackers, toast, dry cereals or bread sticks, when you wake up and every few hours during the day
  • avoid foods or rooms with strong odours
  • avoid hot or spicy foods
  • avoid foods that are overly sweet, greasy or fried
  • remain seated upright for at least an hour after eating
  • avoid drinking with meals
  • eat bland, soft, easy-to-digest foods on treatment days such as egg custards and soup with crackers.
  • avoid eating your favourite foods until you feel well enough to enjoy them


These are some common suggestions for how to ease or prevent constipation:

  • eating foods which are high in fibre (e.g. wholegrain food, fresh fruit
    and vegetables)
  • drink plenty of water
  • try to do some gentle exercise

Taste changes

Treatments such as chemotherapy can sometimes affect your senses of taste and smell. People have often described a bitter or metallic taste in the mouth. Below are some suggestions on how to make your eating experience more enjoyable:

  • rinsing your mouth and brushing your teeth frequently
  • using plastic cutlery helps to deal with the metallic sensation
  • eating fresh food instead of tinned
  • seasoning foods with flavours such as lemon, vinegar, and pickles. (Avoid if you have a sore mouth)
  • adding herbs and spices, such as garlic, chilli, basil, oregano, rosemary, tarragon, coriander or mint to your dishes

Big appetite due to medicines

A side-effect of steroids is to increase appetite significantly, and maintaining a healthy weight might become more difficult.

  • eating foods which are high in protein and fibre can keep you fuller for longer
  • avoid foods which are high in saturated fats or trans-fatty acids as much as possible

The list of food related side-effects addressed above is not exhaustive. If these side-effects get worse or if you are experiencing other food related side-effects of treatment, discuss them with your doctor or a registered dietitian who can assist you further.

The ketogenic diet and brain tumours

The ketogenic diet (KD) is a special high fat, low carbohydrate diet which also requires careful measurement of proteins. It is called ketogenic because it restricts carbohydrate intake, forcing the body to produce an alternative form of energy molecule from fat, called ketones. This diet was first used almost a century ago as a way to manage epilepsy in children who didn't respond to existing medication.

Over the past few years there has been a surge in interest regarding the potential of the KD in treating brain tumours and related seizures. Supporters of the KD argue that cancer cells are dependent solely on sugars (simple carbohydrates) and so strictly reducing the intake of carbohydrates and sugar can starve the tumour, while the body fulfils its energy needs by producing and using ketone molecules.

Unfortunately, there is currently no scientific evidence supporting the effectiveness of the KD in treating brain tumours. If you still want to try this diet, please consult with your doctor or registered dietitian because, without proper monitoring, KD can cause a rapid and potentially harmful loss of weight. It can also affect your standard treatment and interfere with observations of your condition by your medical team. Consultation with your doctor is particularly important for anyone with a pre-existing medical condition, such as diabetes.

Page last reviewed: 02/2016
Next review due: 02/2019

Page last reviewed: 05/2015

Next review date: 05/2018

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