ABSTRACT
Man needs food to provide energy for the body’s essential physiological functions like respiration, circulation, metabolism and so on, for maintaining body temperature, for the growth and repair of the body’s tissues, and for obtaining essential nutrients for the several biochemical processes essential in body metabolism. From the beginning of the practice of agriculture, there has been a tendency to concentrate on those species of plants that are most productive and rewarding in terms of labour invested. The supermarkets and convenience foods have further restricted choice in diets in urban industrial societies and through the development of multinational corporations are exerting their influence on Third World countries as well. As human society has evolved and the knowledge of agriculture and farming has increased, man has evolved increasingly complex systems through which land can be worked and food obtained and processed for use.
