单选题
Increasingly, over the past ten years, people—especially young people—have become aware of the need to change their eating habits, because 1 of the food they eat, particularly processed foods, is not good for health. Consequently, there has been a 2 interest in natural foods: foods which do not contain chemical additives and which have not been affected by chemical fertilizers widely used in farming today.
Natural foods, for example, are vegetables, fruit and grain 3 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 4 essential vitamins and minerals. This in itself is a natural process 5 with the use of chemicals and fertilizers, the main purpose of which is to increase the amount but not the 6 of foods grown in commercial farming areas.
Natural foods also include animals which have been allowed to feed and move 7 in healthy pastures. Compare this with what happens in the mass production of poultry: 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 8 rubbish. Chickens kept in this way are not only 9 as food; they also produce eggs which lack important vitamins.
There are other aspects of healthy eating which are now receiving increasing 10 from experts on diet. Take, for example, the question of sugar. This is actually a nonessential food! 11 a natural alternative, such as honey, can be used to sweeten food if this is necessary, we can in fact do 12 it. It is not that sugar is harmful in itself. But it does seem to be additive: the quantity we use has grown steadily over the last centuries and in Britain today each person consumes an average of 200 pounds a year! Yet all it does is to provide us with energy, in the 13 of calories. There are no vitamins in it, no minerals and no fiber.
It is significant 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 14 in unrefined flour and of course in vegetables. It is interesting to note that in countries where the national diet 15 large quantities of unrefined flour and vegetables, certain diseases are comparatively rare. Hence the emphasis is placed on the eating of whole meal bread and more vegetables by modern experts on "healthy eating".