Obesity in Preschool Children Is More Prevalent and Identified at a Younger Age When WHO Growth Charts Are Used Compared with CDC Charts

Our objective was to compare the prevalence and determinants of child obesity using the WHO child growth standards compared with the CDC growth reference. We used data from 143,787 2- to 5-y olds who participated in the Massachusetts Special Supplemental Food and Nutrition Program for Women, Infants and Children (WIC) program between 2001 and 2006. The prevalence of obesity (>95th percentile, BMI-for-age) was 23.3% when we used the WHO standards vs. 16.9% using the CDC reference; for obesity plus overweight (>85th percentile), the prevalence was 42.2 vs. 33.8%, respectively. The difference between the prevalence estimates was greatest at 24-36 mo of age. Multivariate logistic regression analysis indicated that child obesity (based on the WHO standards) was more common in boys, Hispanics, children of less educated mothers, and those born to obese mothers. These results confirm that the prevalence of child obesity is higher according to the WHO standards and indicate that the WHO charts allow for a more timely detection of obesity in childhood.