ABSTRACT
The chapter summarizes what is newly known about nutritional requirements and their variation worldwide. Some progress has been made in defining and evaluating levels of nutritional deficiency for comparative purposes. The energy requirements of individuals depend on their physical activity, body size and composition, and age, as well as on climate and other ecological factors. In setting protein recommendations the Food and Agricultural Organization/ World Health Organization expert group stated that: "The safe level of protein intake is the amount of protein considered necessary to meet the physiological needs and maintain the health of nearly all persons in a specified group." Diets can be easily ranked according to the percentage of total calories supplied by the starchy staples. Diets ordinarily contain mixtures of proteins that, to some extent, have complementary patterns of amino acids. The relative protein value of a diet made up principally of cassava, for example, is likely to be around 60 or below.
