Prevalence and regional differences in overweight in 2001 and trends in BMI distribution in Swedish children from 1987 to 2001

Aims: This study was undertaken to assess current prevalence and regional differences of overweight in 2001 and changes in body mass index (BMI) distribution between 1987 and 2001 in Swedish adolescents. Methods: Comparison was made of two independent samples. For assessment of prevalence and regional differences in 2001, a total of 1732 subjects were used. For trend analyses a total of 1,949 children ( 516 and 1,470 in 1987 and 2001, respectively), aged 10, 13, and 16 years. Results: The prevalence of overweight in 2001 was between 21.7% and 13.3% for boys and girls aged 10 to 16 years and the prevalence of obesity was between 2.9% and 6.2%. Mean BMI as well as prevalence of overweight and obesity was higher in subjects from schools in smaller towns or from the countryside. Median BMI among adolescents changed from 1987 to 2001, most notably in 13- and 16-year-old children. The prevalence of overweight and obesity combined has changed more than 2.5-fold in children aged 10 to 16 years. In this study, the most pronounced elevation in BMI is found in the upper part of the BMI spectrum. This change is especially apparent in girls. Conclusion: The change in mean BMI and prevalence of overweight and obesity in children in this study is mainly due to the pronounced change in BMI at the upper end of the spectrum, indicating that the factors leading to overweight or obesity have changed in only a subgroup of the child population.