Growth standards for poor urban children in nutrition studies.

In order to estimate the importance of a variety of environmental and dietary factors as determinants of growth in a group of 123 poor Peruvian urban children between 2 and 19 years old, we found it necessary to express anthropometric measurements in units that were not age- or sex-dependent. Height quotient and weight quotient for each child were calculated from height and weight ages derived from the 50th percentile of the Boston reference data for the appropriate sex. Only 5% of the children had heights above the Boston 50th percentile (height quotient greater than 100) and 18% had weights above the 50th percentile (weight quotient greater than 100), but 88% had weights that were appropriate or excessive for height (weight/height quotient greater than or equal to 1.00). Some CATch-up" gains in relative height and weight were apparent in preschool children but more impressive gains in both linear and ponderal growth, relative to the Boston data, were evident between 8 and 13.5 years in girls and 10 and 17 years in boys. When the same quotients were calculated for a much larger sample from the same socioceonomic level it seemed likely that this last peak was due to earlier puberty and sexual maturation, and that quotients derived from the Boston data would have different meanings at different ages, making them inappropriate for further statistical analysis. New quotients for the study population, derived from the larger Peruvian group, did not have sex- or age-dependent trends. Racial and regional differences in patterns of growth must be taken into account in the interpretation of anthropometric and nutritional data.