阅读理解
Increasingly, over the past ten years, people－especially young people－have become aware of the need to change their eating habits, because much of the food they eat, particularly processed(加工过的)foods, is not good for health, so there has been a growing interest in natural foods：foods which do not contain chemical additives(添加剂)and which have not been affected by chemical fertilizers widely used in farming today．
Natural foods, for example, are vegetables, fruit and grain which have been grown in soil that is rich in organic matter．In simple terms, this means that the soil has been nourished by unused vegetable matter, which provides it with basic vitamins and minerals．This in itself is a natural process compared with the use of chemicals and fertilizers, the main purpose of which is to increase the amount but not the quality of foods grown in commercial farming(经济农场)areas．
Natural foods also include animals which have been allowed to feed and move freely in healthy grassland．Compare this with what happens in the mass production of poultry(家禽)：there are battery farms, for example, where thousands of chickens live crowded together in one building and are fed on food which is little better than rubbish．Chickens kept in this way are not only tasteless as food; but also produce eggs which lack important vitamins．
There are other aspects of healthy eating which are now receiving increasing attention from experts on diet．Take, for example, the question of sugar．This is actually an unimportant food!Although a natural choice, such as honey, can be used to sweeten food if this necessary, we can in fact do without it．It is not that sugar is harmful in itself．Yet all it does is provide us with energy, in the form of calories．There are no vitamins in it, no minerals and no fiber．It is important that nowadays fiber is considered to be an important part of a healthy diet．In white bread, for example, the fiber has been removed．But it is present in unrefined(未精炼的)flour and of course in vegetables．Thus the emphasis is placed on the eating of whole meal bread and more vegetables by modern experts on “healthy eating”．
