Comparison of anthropometry and parent-reported height and weight among nine year olds

Background: There is mounting evidence that the prevalence of overweight and obesity in children is reaching epidemic proportions in North America. We compared parent-report vs. measured BMI overweight and obesity prevalence estimates among 9 year olds using the 1996 NLSCY reports published by Willms et al. (2003) and anthropometric measurements from a regional population of public school children. Methods: Body mass index (BMI) was calculated for 1,497 9-year-old children (males N=734; females N=763) from 75 public schools in the Niagara Region of Ontario, Canada. BMI from the 1996 NLSCY was based on parental reports of height and weight of 879 nine year olds. To define overweight and obese children, we used internationally accepted age- and gender-specific cut-offs as defined by Cole et al. (2000). Results: The NLSCY overweight prevalence estimates of boys and girls may overestimate overweight boys and girls by 17% and 10%, respectively. Measured obesity prevalence estimates were similar to parent-reports. Conclusions: Our results suggest that parental reports of height and weight may inflate prevalence estimates of overweight children, but appear reasonably accurate for estimating obesity. Since prevalence of overweight and obesity are often combined to form a global estimate, reliance on parent-reported height and weight may overstate the magnitude of the problem