About food types

Different food types give your body different nutrients and energy. Knowing about these can help you to get the right balance that your body need.

If you are losing weight, eating higher energy foods can help to prevent losing more, and can help you gain weight.

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. Glucose is a type of sugar that 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, you need energy to breathe, even when you are sitting down.

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


The main role of fibre (roughage) 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. It 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 help you to put on weight or prevent further weight loss.

There are two types of fat:

  • Saturated fats are found mainly in meat, pies, sausages, butter, cheese, ghee, coconut oil, cakes and biscuits.
  • Unsaturated fats are found mainly in vegetable-based cooking oils and spreads, nuts, avocado, seeds and oily fish such as salmon, sardines and mackerel.

Generally, it is important to try to eat less fat, and to choose foods that contain unsaturated fats instead of saturated fats. But if you are trying to gain weight, you may need to have more fat in your diet.


Your body needs protein to do things like building and repairing muscles and other body tissues. When we are ill, injured or stressed, we need extra protein (as well as extra energy) to repair any damage.

Protein-rich foods can also be a good source of vitamins and minerals. There is protein in:

  • red meat
  • poultry, such as chicken and turkey
  • fish
  • dairy products, such as milk and eggs
  • pulses, such as peas, beans and lentils
  • some plant-based meat alternatives, such as soya, tofu and mycoprotein (Quorn).

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 a healthy balanced diet with plenty of fruit and vegetables, 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.

High-dose vitamin and mineral supplements are not recommended during cancer treatment. It is not known if they will affect how your treatment works.

About our information

  • References

    Below is a sample of the sources used in our building-up diet information. If you would like more information about the sources we use, please contact us at cancerinformationteam@macmillan.org.uk

    European Society for Clinical Nutrition and Metabolism (ESPEN). ESPEN guidelines on nutrition in cancer patients. February 2017 www.espen.org [accessed Jan 2020] 

    European Society for Clinical Nutrition and Metabolism (ESPEN). ESPEN expert group recommendations for action against cancer related malnutrition. June 2017 www.espen.org [accessed Jan 2020] 

    World Cancer Research Fund (WCRF). Healthy living after cancer. 2016. www.wcrf-uk.org [accessed Jan 2020]      

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Chief Medical Editor, Professor Tim Iveson, Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.