Ohri-Vachaspati P, et al. - Via population-based studies, the researchers intended to carry out professional measurement of heights and weights measurements representing the criterion standard for calculating body mass index (the most feasible and frequently used measure of body weight status of children), for the assessment of the weight status of children. The collection of professionally measured data on sufficient samples of children in population studies was extremely resourced and intensive. Hence, these studies relayed on the child- or parent-estimated heights and weights. However, the estimated values were easy to collect, but they were at risk of misreporting, with systematic deviations across sociodemographic characteristics.