INTRODUCTION
Evaluation of nutritional status of population groups has been undertaken in many areas of the world during the past 40 years. Attempts have been made to standardize procedures and methodologies in order to allow comparisons of results from different studies.13
During the 1950s and 1960s, under the auspices of the Interdepartmental Committee on Nutrition for National Defense, a number of surveys were undertaken in developing countries of the world where children comprise the majority of the population. The preschool child was particularly vulnerable to malnutrition and mortality rates were quite high, often exceeding 50% in the first five years of life. Most infants in these countries seemed to thrive during the first 6 to 12 months of life, particularly if they were breast-fed. After this period, their diets declined nutritionally, both in quality and in quantity. Combined effects of malnutrition and of infection largely accounted for the high mortality rates in the postweaning age.
In view of such high mortality rates, it was obvious that a substantial proportion of youngsters who did not die almost surely experienced overt malnutrition or some degree of nutritional deprivation during critical periods in development. Increasing attention has been given to study of these "survivors" from the standpoint of physical and intellectual development and behavioral characteristics.4-9
It was apparent in the mid 1960s that we knew little about the nutritional status of young children in the United States. Studies had been undertaken on various segments of the U.S. population,10 but were often limited in scope (only dietary surveys or anthropometric determinations) and in sample size (adolescents or adults in selected areas or occupations).