How to maintain a healthy diet

Making changes to eat healthier food can seem difficult. Try to improve your diet progressively. You can use the opportunity to discover and try new foods. It can take time to find a diet that works for you, but your GP or dietitian can give you advice. It may help to make gradual changes and set small, realistic goals.

Alcohol can increase the risk of developing certain cancers. According to the national guidelines, men should avoid drinking more than 3–4 units of alcohol a day; women should not have more than 2—3 units a day.

A balanced diet contains a variety of foods. Try to eat lots of fruits and vegetables, and include plenty of starchy foods (such as cereals, bread and pasta) in your diet. Your body also needs protein, found in foods such as fish and meat. You should try to avoid eating too much fat, sugar and salt.

Food labels can guide you and help you choose healthier options.

Making changes

It’s not always easy to make major changes to our lives. It can be even more challenging when you have to cope with cancer, and perhaps cancer treatment too.

Some people turn to food when life is stressful, which is known as comfort eating. For others, being busy means we don’t have time to look at healthier options when we’re food shopping. It can sometimes be easier to choose ready meals. For some people, the cost of food is an issue. So you may want to change the way you eat, but thinking of how to do it may feel too hard.

It may help to make healthy changes to your diet gradually, at a comfortable pace, at a budget you can afford, and when you feel ready. You could start by writing down what you normally eat for a few weeks. Compare this with information on healthy eating. Then set yourself some small, realistic goals, and decide how you will achieve them. For example, if you’ve never had fruit with breakfast; try adding fresh or stewed fruit, or a glass of fruit juice. For snacks, you could try swapping chocolate with a small portion of dried fruit and nuts. Gradually increase your goals over time. Keep track of your progress and how you feel physically and emotionally. Making changes can be enjoyable, as you may discover new foods that you haven’t tried before.

If you’re not sure how to go about changing your diet, ask your GP or specialist nurse. A dietitian can help you make these changes, and also advise you about any other dietary problems during or after your cancer treatment.

Whether you want to make small or big changes to your diet, it may take time to find healthy foods that you like, or a diet that works for you. It can help to try different foods. This can stop you getting bored and may help motivate you to continue a healthy diet in the long-term.

Alcohol and staying healthy

Alcohol has been linked with an increased risk of developing some types of cancer. An American study has shown that  as little as one drink a day can increase the risk of mouth, gullet (oesophagus), breast, liver, and bowel cancers. The more alcohol someone drinks the greater the overall health risk. Alcohol is also high in calories and can contribute to weight gain. Drinking a large amount of alcohol in one session (binge drinking) is thought to be worse for your health than drinking a small amount each day.

Recommended guidelines

It’s best to limit alcohol intake and include one or two alcohol-free days each week. Current drinking guidelines recommended by the UK government and the NHS are:

  • Men should avoid drinking more than 3–4 units of alcohol a day.
  • Women should avoid drinking more than 2–3 units of alcohol a day.

Drinking one or two units of alcohol a day may give some protection from coronary heart disease, especially in men over 40 and women who have been through the menopause.

However, it is a relatively small benefit. 

One drink isn’t the same as 1 unit of alcohol. In the UK, 1 unit is 10ml (8g) of pure alcohol. For example: 

  • Half a pint of lower strength (3–4%) beer, lager or cider contains 1 unit. 
  • Half a pint of higher strength (5%) beer, lager or cider contains 1.5 units. 
  • A standard glass of wine (175ml), often called a small glass in pubs and bars, contains 2.1 units. 
  • A large glass of wine (250ml) contains 3 units. 
  • A single measure (25ml) of 40% spirits contains 1 unit. 
  • A bottle (275ml) of an alcopop contains 1.5 units.

Know your food types

Few of us have time to check the energy content of everything we eat. But knowing about the different types of foods can help you to control what you eat and help with weight loss.

Fruits and vegetables

Fruit and vegetables are a good source of vitamins, minerals and fibre and are low in fat. Aim to eat at least five portions a day. One portion of fruit or vegetables can be:

  • one apple or banana
  • a slice of melon
  • two small fruits such as kiwi fruit or plums
  • a handful of berries
  • twelve chunks of tinned pineapple
  • a glass of orange juice (only counts once a day)
  • one whole vegetable such as an onion or small pepper
  • three heaped tablespoons of diced carrots or shredded cabbage
  • one cereal bowl of mixed salad
  • seven cherry tomatoes
  • two broccoli florets
  • three heaped tablespoons of peas or lentils.

To increase your daily intake of fruit and vegetables, try the following:

  • Have a mixed salad as a starter or as a side dish with your main meal.
  • Reduce meat portions and enjoy larger servings of vegetables and salad.
  • If you need a snack between meals, choose fresh fruit.

Try to avoid adding butter, rich sauces or dressings to vegetables and salads as this will increase the energy you take in. Frozen vegetables and tinned fruit in juice (not syrup) are just as nutritious as fresh ones and can be less expensive.

Starchy foods

Starch is a type of carbohydrate, which is a good source of energy. Foods like bread, cereal, rice, and pasta are starchy foods. Wholegrain varieties are better if you’re trying to lose weight as they make you feel fuller. Starchy foods should make up about one-third of what you eat in a day.

Potatoes are also included in this food type. Boiled or baked potatoes are healthier than deep fried chips. If you want to eat chips, use the low-fat oven varieties.


Increasing the amount of fibre in your diet can also help you feel fuller more quickly. Try changing to wholemeal bread and high-fibre breakfast cereals. Peas, beans, lentils, grains and seeds are other good sources of fibre, as well as fruit and vegetables.


Fish is a good source of protein, vitamins and minerals and is low in saturated fat. Aim to have at least two portions of fish a week. Grilling, steaming, poaching and baking fish is healthier than frying it. Frozen fish can be cheaper than fresh, but avoid high-fat fish-based processed meals or fish in batter. Tinned fish like tuna, sardines and pilchards are also low in saturated fat.


Although meat is high in protein and minerals, it can also be high in fat. Try to reduce your meat portions and have more vegetables instead. Choose cuts of meat that don’t have much fat, and grill or roast rather than frying. Skinned turkey or chicken is a healthier, low fat alternative to red meat such as lamb, beef or pork.

Try cutting down on processed meats, such as sausages, burgers, pies and sausage rolls, which are high in saturated fat.

Milk and dairy

Dairy products are good sources of protein, vitamins and calcium, but can also be high in fat. Try semi-skimmed or skimmed milk, low-fat spreads and yoghurt. Only use cream or butter in small amounts.


Sugars are a good source of energy and occur naturally in foods including fruit and milk. But foods such as sweets, biscuits, cakes, pastries and puddings have lots of added sugars. Fizzy drinks and alcohol also often contain a lot of sugar. Cutting down on foods and drinks with added sugar is important to help with weight loss.


Fats also provide us with energy, but are a concentrated source of energy and high in calories. There are two types of fats contained in foods:

  • saturated fats- such as fatty cuts of meat, sausages, pies, butter, ghee, cheese, cakes and biscuits
  • unsaturated fats- such as vegetable-based cooking oils and spreads, nuts, seeds, and oily fish such as sardines or mackerel.

Too much fat in your diet can be unhealthy and lead to weight gain and other health problems. Try to cut down on foods that contain fats but particularly saturated fat.

Food labels can give you a guide to this. If you have a choice, pick foods with unsaturated fats, but remember these are still a high-energy food. Even foods labelled as ‘low fat’ can still be high in calories.


Too much salt in your diet can lead to high blood pressure, which can cause heart disease and strokes. Try to eat no more than 6g of salt a day (that’s about a teaspoonful). Many processed foods and ready meals contain high levels of salt, so always check the label.

Understanding food labels

Most pre-packaged foods have labels on the packaging giving information to help you make healthier choices. You can check which foods are high in fat, salts, added sugars and calories. It may also give information about sodium, salt and fibre levels.

Many food manufacturers and supermarkets use the food traffic light system. The traffic light colours represent the number of grams of fat, saturated fat, sugar or salt per 100g (3½oz) of the product.

The colours show if this is high, medium or low.

  • Red – content level is high. 
  • Amber – content level is medium. 
  • Green – content level is low.

Eat more foods with amber and green labels and fewer with red. The table below can be used to check products that don’t use traffic light labelling. 

A healthy view on food

Food doesn't just give us what we need to keep our bodies healthy and energised. Socially, we often enjoy spending time with family and friends at meals and barbecues, or celebrating with treats like cakes. Sometimes we eat a favourite food to reward ourselves.

Even when you’ve successfully changed to a more balanced diet, you may not always feel like sticking strictly to it. This is normal for all of us. Everyone enjoys having an occasional treat or enjoying a meal out with friends, but maybe try having a smaller portion than you’d normally have. If you’re eating well most of the time, you can allow yourself less healthy foods occasionally.

Another idea is to have one ‘free’ day a week, when you can eat whatever you want. You may quickly find that the healthier you eat, the less you crave the so-called ‘forbidden foods’. Your idea of treats may also change to healthier options.

Back to Healthy eating

Healthy eating

A balanced diet will provide everything you need to keep your body healthy. It will contribute to your well-being.

How a healthy diet can benefit you

Keeping to a healthy weight and maintaining a balanced diet can help reduce the risk of developing some cancers.

How your body uses food

Our bodies need foods from different groups to keep us healthy.

Commonly asked questions about diet

You may have questions about diet and cancer. We have answered some of the most common ones.