Passage Two 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 foods, is not good for the health. Consequently, there has been a growing interest in natural foods. Natural foods, for example, are vegetable, fruit and grain which have been grown in soil that is rich in organic (有机的) matter. In simple terms, this means that the soil has been nourished (滋养) by unused vegetable matter, which provides it with essential vitamins (维生素) 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 quantity but not the quality of foods grown in commercial farming areas. Natural foods also include animals which have been allowed to feed and move freely in healthy farms. 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 than rubbish. Chickens kept in this way are not only tasteless as food they 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 a non-essential food. Although a natural alternative, such as honey, can be used to sweeten food if this is necessary, we can in fact do without it. It is not that sugar is harmful in itself. But the problem is that the quantity we use has grown steadily over the last two centuries and in Britain today each person consumes an average of 200 pounds a year! 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. Why do people now prefer natural foods?