All animals require food that is appropriate to their needs. The food requirements of humans can best be demonstrated by the food pyramid, which shows which foods are required and in what proportions.
A healthy diet contains adequate quantities of six groups of substances – proteins, carbohydrates, fats, fibre, vitamins, and minerals. The first three contain kilojoules (ie. produce energy) and the second three do not. It is also essential to have a supply of safe drinking water, as a person can live for weeks without food, but only a few days without water.
A good well balanced diet should include:-
- protein from foods such as fish or other seafood, poultry, very lean meat, or eggs, dried peas, beans or lentils
- some salad and three or four vegetables, including at least one serve of a green leafy variety and one yellow variety such as carrots
- two or three pieces of fruit
- cereal or grains, such as rice
- bread (some dieticians recommend that this should be wholemeal or wholegrain but others are content with white bread)
- some dairy products, preferably low-fat for most adults (women in particular should ensure that they get an adequate supply of milk, yoghurt or cheese to prevent the loss of calcium in their bones after menopause which causes osteoporosis).
Why do we need food?
- We grow in size and number of cells – and that needs material;
- Cells do die after a certain amount of use, after injury or after disease. Such cells disintegrate , get expelled from the body and need to be replaced;
- Body fights against bacteria, viruses and all diseases and needs to form certain cells and bodies or substances all the time;
- Body produces hormones and enzymes – bio-chemicals, that help the reactions going on inside the body;
- Every single organ and most of the hundred trillion cells of the body work 24/24 non-stop; Work needs energy – fuel, to supply calories/kilojoules