The extent of overweight index in children and adolescents from Cracow, Poland (1971-2000).

Abstract Obesity indices describe the percentage of overweight and obese children in a given population but they do not show the extent to which the norms have been exceeded. The aim of this work was to determine the extent of overweight index (EOW), suggested by Jolliffe (2004a,b) , by examining children and adolescents from Cracow in order to obtain information on overweight and obesity prevalence and on the amounts by which the BMI age- and sex-specific norms are exceeded, emphasising usefulness of EOW in population studies. The study material comprises three randomly selected groups, representative for Cracow: (1) measured in 1971 which includes 4090 individuals of both sexes and aged 7–19 years, (2) measured in 1983 with 6542 individuals aged 3–19 years and (3) measured in 2000 with 4524 boys and girls aged 3–19 years. The EOW index of overweight is a mean relative deviation from BMI threshold, assuming that for values lower than the threshold ones, the deviation amounts to zero. The EOW index values in boys increased from 0.9 in 1971 up to 2.2 in 2000 i.e. by 144%, indicating an increase of both prevalence of overweight and obesity and an increase of the amount by which the limits of overweight are exceeded. In girls the index also increased, though less dramatically, from 0.7 in 1971 to 1.5 in 2000 i.e. by 114%. An analysis of the results showed that the increasing prevalence of overweight and obesity in children and adolescents is accompanied by an increase of the amount by which the BMI threshold values are exceeded.