*. For the production of heat.
*. For the regulation of body processes.
*. For the growth, repair, and reproduction.
*. In the reaction of the body against disease.
*. To provide the minerals required by the body for cells, body fluids, and bones.
*. To keep a proper water balance.
Everywhere in the world the foods eaten by various communities differ a great deal, but all these different foods are actually made up of the same substances or nutrients:
Proteins or body-building material, Fats and starches used especially for energy, Minerals, Vitamins that are used in many processes in the body and are necessary in small quantities for health, Water, Roughage.
Nutrients and Common Foods
Protein
Protein is necessary for the growth and repaids of all body cells. There are two kinds: Animal protein which comes from meat, fish, cheese, eggs, and milk, including, of course from peas, beans, nuts, lentil, gram, some constituents of cereals (for example millet, maize, rice, oatmeal and sorghum), and even green leaves.As many people in the tropics grow their own food, these body-building foods from their own garden are a very important part of tehr diet. Proteins in fact are made up of different types of amino acid, and plant proteins by themselves do not contain all the necessary amino acids, so that it is always best to add a little animal protein to the diet even though it is the most expensive form of protein.
Fat
Fat is useful in the body to prevent the diet from being too bulky, because it provides a high food value for energy in a small amount of food.Most of the stored energy in the body consists of fat.
It is found: In animal sources–fat meat such as pork or mutton, lard (pig's fat), butter or ghee, fish oil, dried lake fish, tinned fish, bacon, egg yolk, cheese, milk. Termites, grasshoppers, and locusts.
In vegetable sources–nuts of every kind, for example coconuts, shea nuts, oysternuts; margarine and manufactured cooking fat; red palm oil, cotton seed oil, sesame oil, olive oil. Sunflower seed oil, avocado pear, soya bean, groundouts, and passion fruit.
Starches (Carbohydrates)
These are changed during digestion into glucose, stored as glycogen, released when required as glucose, used in the muscles to provide energy.Starches are filling for the stomach and being most quickly digested provide immediate energy. Starch is the cheapest kind of food and that is why all over the world it forms the bulk of the diet.
Minerals
Minerals are necessary for: Building tissue cells, and bones and teeth, the working of muscles, the clotting of blood, providing the red blood cells with haemoglobin.There are a large number of minerals necessary for the health of the body, and it only needs a very small amount of them to keep well. These are minerals like iodine, magnesium, sulphur, and copper. Some, however, are required in greater amounts, for example iron, calcium, sodium, and phosphorus. All these minerals exist in food as mineral salts in a form that can be absorbed by the body.
Iron is needed for: the formation of haemoglobin to carry oxygen around the body in the blood.
It is found in: liver, kidney, meat, poultry, eggs, dried fruit, molasses, yeast, cocoa powder, beans, dark green leafy spinach, kale, and leaves of cowpea, pumpkin, and cassava.
Iron is very important in the diet of mothers and children in developing countries especially where there are parasites such as the hookworm that lead to chronic blood loss.
Calcium and phosphorus are need for:
The development of bones and teeth.
The making of cells and the blood.
Children, pregnant and lactating women, and old people need a diet with adequate calcium.
It is found in: milk, butter and cheese, dried fish, especially if grounded to bones, millet and sesame seeds, peas, beans, nuts, and bone soup.
Sodium is needed for:
Every body cell.
Every body fluid.
It is lost in urine and sweat, and people who do very heavy work in hot climates, like farmers, miners, and woodcutters, need more, as they lose more in sweating.
It is do found in: common salt (sodium chloride), and foods that are salted like bacon, bread, and dried fish.
Pottasium is needed for the blood and cells of the body.
It is found in: meat, milk, eggs, fish, tomato, and banana juice.
This mineral is often given to children suffering from kwashiorkor and diarrhoea.
