Know your food types

A balanced diet will provide you with everything you need to keep your body working well. Foods fall into different groups, all of which are used in a specific way by our bodies. They include:

  • Fruit and vegetables – these are a good source of vitamins, minerals and fibre.
  • Starchy foods (carbohydrates) – these turn into glucose to give us energy. Energy is measured as calories. If we have too many calories, we put on weight. Men need about 2,500 calories a day and women about 2,000.
  • Fibre – this is a good source of iron and vitamin B, and gives us energy.
  • Fats – these bring condensed energy to the body.
  • Protein – the amino acids in protein help the body build muscle and repair tissue. When we are unwell, it is important to have protein.
  • Vitamins and minerals – these help our bodies work normally. Minerals help maintain healthy bones and nerves, for example.
  • Fluid – to function properly, the body needs fluid. Women should try to drink roughly 8 glasses (about 1.6 litres) of fluid a day, and men should try to drink about 10 glasses (about 2 litres) a day.

Fruit and vegetables

Fruit and vegetables are a good source of vitamins, minerals and fibre.

Starchy foods (carbohydrates)

Starchy foods (carbohydrates) are an important part of a healthy diet. They are a good source of energy and contain nutrients, including fibre, calcium, iron and B vitamins.

Starchy foods are broken down in the body to become glucose, which gives us energy. Energy is measured in calories. We all need a certain number of calories each day for energy, even if we are not being very active. For example, we need energy to breathe when just sitting in a chair.

The amount of energy a person needs each day varies. It depends on how quickly their body uses the energy, and on their level of activity. An adult man needs about 2,500 calories a day and an adult woman needs about 2,000 calories. If we have too many calories, we put on weight. If we do not have enough, we use up our body’s energy stores and lose weight.

Fibre (roughage)

The main role of fibre is to keep the digestive system and bowels healthy and prevent constipation. Fibre is the part of cereals, fruits and vegetables that is not digested and passes down into the gut.


Sugar is a good source of energy and is found naturally in some food and drinks, such as fruit and milk. The body also gets glucose (a type of sugar needed for energy) by breaking down carbohydrates.


Having some fat in our diet helps us to absorb vitamins A, D, E and K. Foods that are high in fat are also high in energy (calories). This means eating a lot of fat can make you more likely to put on weight and develop other health problems.

There are two types of fat:

  • Saturated fats are found mainly in fatty cuts of meat, sausages, pies, butter, ghee, cheese, cakes and biscuits.
  • Unsaturated fats are found mainly in vegetable-based cooking oils and spreads, nuts, seeds and oily fish such as sardines and mackerel. Unsaturated fats are still high-energy (high-calorie) foods.

Generally, it is important to try to eat less fat, and to choose foods that contain unsaturated fats instead of saturated. Even foods labelled as ‘low fat’ can still be high in calories. However, if you are trying to gain weight, you may need to have more fat in your diet.


Your body needs protein to perform a wide range of functions, such as building and repairing muscles and other body tissues. We need extra protein (as well as extra energy) when we are ill, injured or stressed, to repair any damage. Protein-rich foods can also be a good source of vitamins and minerals. Protein is found in red meat, poultry (such as chicken and turkey), fish, milk, dairy foods, eggs and pulses (such as peas, beans and lentils). It can also be found in soya, tofu and mycoprotein (Quorn), which can replace mince, burgers and sausages as a source of protein.

Vitamins and minerals

The body needs minerals for various functions, such as maintaining healthy nerves, bones and teeth. Vitamins are essential to help our bodies work normally, but we only need tiny amounts of them. If you are eating even a small amount of the main food types that contain vitamins, you are probably getting enough vitamins. But if you are not able to eat well for a long period of time, you may need multivitamins and mineral supplements. Your doctor, dietitian or pharmacist can give you more advice about these.


Our bodies need a certain amount of fluid each day to work properly. It may be difficult to drink enough liquid when you don’t feel well. Women should try to drink roughly 8 glasses (about 1.6 litres) of fluid a day, and men should try to drink about 10 glasses (about 2 litres) a day.

Water is the best for hydration, but it contains no extra nutrients such as energy or vitamins. Milk, smoothies and not-from-concentrate or freshly-squeezed fruit juices contain a lot of energy and nutrients, so they may be good choices if you are struggling to eat well. Soft and fizzy drinks that contain a lot of sugar are high in energy, but they do not contain any other nutrients. The sugar and acidity may also harm your teeth.

Drinks that contain caffeine include coffee, tea and some fizzy drinks. These can make you need to wee more often. You can include them as part of your normal fluid intake. But make sure that you drink other fluids that do not contain caffeine as well.

Back to Preventing weight loss

The building-up diet

If you’ve lost weight during your cancer treatment, the building-up diet will help provide you with more energy.

Stock your cupboards

There are several types of food that can be particularly helpful in the building-up diet.

Meal ideas

You can increase your energy intake by preparing your meals slightly differently. Our menus offer  some suggestions.