INCREASE OF THE PREVALENCE OF OVERWEIGHT AND OBESITY

Is the Increase in Childhood Obesity Due to a Shift of the Entire BMI Distribution or an Increase of the Upper Tale?
 

An increase of the prevalence of overweight and obesity, as reported above, can be either due to a shift of the whole BMI distribution or only part of it. If the entire distribution shifts, the 50th percentile (median) will shift as well. If only the upper percentiles of the distribution alter, i.e. fat children get fatter, the median is not affected. Data from three German school entrance examinations 5 years apart [34] revealed only alterations of the skewness of the BMI distribution (fig. 1).The median of the BMI in 5- to 6-year-old boys and girls remained stable, whereas the 90th and 97th percentiles increased in both sexes. Of note, children of non-German origin, most of them progeny of Turkish immigrants, showed a different pattern: the median for the BMI increased as well. In the US nationwide study NHANES III, the heaviest children were markedly heavier than in previous studies, whereas the rest of the BMI distribution showed little change [35]. The phenomenon of a high increase of the upper percentiles and a moderate increase of the median has also been observed in the
 

Bogalusa Heart Study in Louisiana, USA, [4] in Spain [36] and in Denmark [37].
Essentials
• High prevalence rates of childhood obesity observed in developed countries are now increasingly found in developing countries, as well.
• The obesity risk groups in developed countries are the poor, rural children with low socio-economic status, whereas urban upper class children with Western life style belong to the risk groups in developing countries.
• In Western societies children of minorities and migrants are more likely to
be obese.