The World Health Organization recommended in 1978 that the National Center for Health Statistics/Centers for Disease Control growth reference curves be used as an international growth reference. To permit the expression of growth in terms of standard deviations, CDC developed growth curves from the observed data that approximate normal distributions. Because of significant skewness, standard deviations for weight-for-age and weight-for-height were calculated separately for distributions below and above the median. Standard deviations below the median were calculated from the 5th, 10th, 25th, and 50th observed percentiles while those above the median were based on the 50th, 75th, 90th, and 95th observed percentiles. Height-for-age distributions did not show significant skewness, thus, the standard deviations were calculated based on all six of the above observed percentiles. The normalized reference curves provide a highly useful data base that permits the standardized comparison of anthropometric data from different populations.

Diarrhea is a leading cause of death in tropical countries. One of the highest childhood mortalities is in northeastern Brazil, where little is known about the morbidity, etiology, and risk factors of diarrhea. Prospective village surveillance over 30 months revealed diarrhea attack rates of more than seven episodes per child-year at six to 11 months of age among the children of the poorest families. Other risk factors included early weaning and the lack of toilets. Diarrhea led to weight loss and stunted growth. Enterotoxigenic Escherichia coli and rotaviruses were the most common pathogens, accounting for 21% and 19% of cases, respectively, followed by Shigella species (8.0%), Campylobacter jejuni (7.5%), Giardia species (6.7%), Strongyloides species (5.3%), and enteropathogenic E coli serotypes (4.6%). Most (84%) enterotoxigenic E coli were isolated during the rainy season of October to March (P less than 0.03), whereas 71% of rotaviral illnesses occurred during the drier months of June to October (P less than 0.03). In the present study, the early occurrence and nutritional impact of diarrhea and weaning, as well as the major etiologic agents of diarrhea and their different seasonal patterns have been defined for this region in which life-threatening diarrhea is endemic.

Objective. To determine whether the prevalence of overweight in preschool children has increased among the US low-income population. Design. Analysis using weight-for-height percentiles of surveillance data adjusted for age, sex, and race or ethnicity. Setting. Data from 18 states and the District of Columbia were examined.a Subjects. Low-income children <5 years of age who were included in the Centers for Disease Control and Prevention Pediatric Nutrition Surveillance System. Results. The prevalence of overweight increased from 18.6% in 1983 to 21.6% in 1995 based on the 85th percentile cutoff point for weight-for-height, and from 8.5% to 10.2% for the same period based on the 95th percentile cutoff point. Analyses by single age, sex, and race or ethnic group (non-Hispanic white, non-Hispanic black, and Hispanic) all showed increases in the prevalence of overweight, although changes are greatest for older preschool children. Conclusion. Overweight is an increasing public health problem among preschool children in the US low-income population. Additional research is needed to explore the cause of the trend observed and to find effective strategies for overweight prevention beginning in the preschool years.

The WHO international growth reference was reviewed to identify characteristics that might affect the interpretation of anthropometric indicators derived from it. Discontinuities were found at the junction point of the two distinct data sets from which the reference curves are derived. Also, the Z-score derived percentile curves for weight-for-age and weight-for-height did not join due to differences in the variances of the two portions of the reference. Empirically an examination of data from international nutrition surveys revealed an artifactual drop in the prevalence of low height-for-age, low weight-for-height, and high weight-for-height at age 2 y, which is due substantially to these discontinuities rather than to intrinsic changes in nutritional status with age. Strategies are discussed for the interpretation of anthropometric indicators in light of these characteristics of the international reference.

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