Abstract
On the basis of calculations using regional and country food balance sheets, dietary surveys from Pakistan and India, and amino acid composition data, it is proposed that the essential amino acid lysine may be relatively lacking in many areas of the world where diets heavily based on cereals are consumed. By combining food balance sheet and gross national product data, it can be demonstrated that as wealth increases, not only are more food energy and protein available, but there are also major changes in the pattern of foods selected. When dietary and health data are stratified by gross national product, the poorest countries, with a combined population of nearly 3,000 million, have the highest proportion of their protein originating from plant sources. These are also the countries with the lowest life expectancy and the highest mortality rate among children under five years of age. Rich countries, in contrast, obtain much of their protein from animal sources. Such different dietary patterns of the rich and the poor lead to very different daily availabilities of lysine Although large differences also exist for all other essential amino acids, the difference is considered to be nutritionally significant only for lysine The coefficient of variation (CV %) in lysine content in some 100 dietary calculations was more than three times the average CV % of the other essential amino acids. The amino acid compositions of animal, pulse, and cereal proteins are also sufficiently different from each other to allow food group data to be used to predict the lysine value of diets. Dietary survey data from both India and Pakistan showed wide intra-country variations of lysine availability. Average lysine values were low in both countries and would indicate a considerable risk of inadequate levels of intake in many subsections of the population. Strategies to alleviate possible global problems of low lysine supply must include improving dietary diversity as well as consideration of cereal nutrient fortification.