Food is needed to help our bodies to move, to grow and to repair themselves after being damaged. Whilst most foods are not unhealthy, many people eat unhealthy diets. The food that we eat and drink each day makes up our diet and it is important we eat a diet that contains a range of different foods since these different foods serve different purposes and provide us with different substances. A balanced or healthy diet is one that consists of the appropriate types of food in the correct quantities. There are seven nutritional categories:
- proteins: essential for the growth and repair of the body. Muscles, skin, hair and nails are nearly 100% protein. Bone is part protein.
- fats and oils: essential for the storage and release of energy, and as an insulator.
- carbohydrates: essential for the making, storage and release of energy and as roughage for the movement of food through the gut.
- minerals: essential for building bones and teeth, for the functioning of the nervous system and for the production of haemoglobin in red blood cells.
- vitamins: essential for the control of chemical reactions in the body and the control of deficiency diseases with symptoms such as poor vision, stomach pains, poor growth and weak bones.
- fibre: acts as roughage in the diet and prevents constipation.
- water: once broken down, the food we eat is dissolved in water in order to be absorbed by the body.
These are often combined into three groups that can be thought of as energy foods, body building foods and maintenance foods.
Food group | Foods | Functions |
Energy: carbohydrates and fats | bread, potatoes, pasta, rice, sugar, fatty and oily foods | Source of energy for movement and warmth |
Body building: proteins | Growth and repair of the body | |
Maintenance: vitamins and minerals | red meats, milk, fresh fruit, vegetables | Maintains healthy bones and teeth, prevents ‘vitamin deficiency’ diseases |
Whilst we could survive without food for several weeks, we could only survive a few days without water. Most of the water we take in is through drinking, but most solid foods also contain water. Nevertheless, to maintain our bodily functions, we need to drink plenty of water every day, eat a diet that has a sufficient energy input level for our energy usage and ensure that there is a balance between the different food groups.