Like vitamins, a wide variety of minerals are essential for good health, growth and body functioning. Some, such as calcium and iron, are needed in quite large amounts, and for some people there is a real risk of deficiency if they do not eat a healthy diet.
Calcium – A regular supply of calcium is vital because bone tissue is constantly broken down and rebuilt. A calcium rich diet is particularly important during adolescence, pregnancy, breast-feeding, menopause, and for the elderly. Smoking, lack of exercise, too much alcohol, high protein and high salt intakes all encourage calcium losses.
Iron – Only a fraction of the iron present in food is absorbed, It is much more readily absorbed from red meat than from vegetable sources. Vitamin C also helps with absorption. Pregnant women, women who have heavy periods, and vegetarians should all be particularly careful about ensuring an adequate intake of iron.
Trace elements – These include other essential minerals such as zinc, iodine, magnesium, and potassium. Although important, they are only needed in minute quantities. They are found in a wide variety of foods and deficiency is very rare.
Trace minerals are needed by the body in much smaller amounts, but are no less important for its functioning than the major minerals.
Fats and Oils – are chemically similar compounds of carbon, hydrogen and oxygen, which are combined in a characteristic way to be different from one another. There are many different types of fats and oils. However, the only difference between fats and oil as a whole is that oils are liquid at room temperature. Most animal fats are hard at normal room temperature. Fats contain twice as much energy, weight for weight, as carbohydrates and so it is important to cut down on fats when dieting. However, fats and oils are important in cooking because they carry flavours and so they should be mixed judiciously with carbohydrate foods.
A well balanced diet is the secret to being in good health and good shape. Balance is important to a healthy diet. The components of food that the body uses to sustain itself are known as nutrients. The nutrients in food fuel the body and provide the material needed for growth, for tissue maintenance and repair and for the regulation of physiological processes. When food is oxidised (burnt) in the body, the result is energy measured in kilocalories (the prefix “kilo” is usually dropped in non technical usage). Carbohydrates and fats are the body’s main sources of energy, providing four and nine calories per gram respectively. Proteins also yield four calories per gram but is used as fuel only when energy from other sources is scarce. Vitamins and minerals are essential for body functioning, although they cannot be burnt as fuel. Strictly speaking, water and fibre are not nutrients, but water is vital to life and fibre plays an important role in elimination.
The human body has the ability to synthesise certain nutrients on its own. Those that it cannot make or cannot make in sufficient quantities (the vast majority) must be supplied by the foods you eat. Such nutrients are known as essential nutrients. If you don’t get enough of them in your diet, you will develop potentially harmful deficiencies.
However no single type of food provides all the nutrients required for good health. You need to eat a wide variety of foods to got various nutrients.
