Cross-national comparison of childhood obesity: the epidemic and the relationship between obesity and socioeconomic status

Background Obesity has become a worldwide epidemic. Recently WHO acknowledged an urgent need to examine child obesity across countries using a standardized international standard. Studies in adults find obesity and socioeconomic factors (SES) factors are correlated, but results are inconsistent for children. Using an international standard, we examined the prevalence of obesity and compared the associations between SES factors and obesity across countries. Methods Data for children aged 6–18 from nationwide surveys in the US (NHANES III, 1988–1994), China (1993), and Russia (1992) were used. We used the recently updated US NCHS body mass index (BMI = wt/ht2) reference to define obesity (BMI ≥95th percentile) and overweight (85th≤BMI