[Overweight and obesity in children and adolescents in Germany].

The increasing prevalence of overweight and obesity is a reason for concern not only in Germany but also in other countries. There are various methods and data sources that can be used to assess the extent of this public health problem. The present publication gives an overview of the reference systems that are in use in Germany to assess body mass index (BMI), which is calculated from height and weight, and an overview from several data sources: the school entry examinations, the HBSC study of the WHO, and the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Current prevalence estimates are based on the KiGGS survey, which found that, based on the Kromeyer-Hauschild reference system, 14.8% of the children and adolescents in Germany aged 2-17 years are overweight, including 6.1% suffering from obesity. In absolute numbers referring to the most recent population numbers, this corresponds to 1.7 million overweight children and adolescents in Germany aged 2 years and older, 750,000 of whom are obese. This description of the status quo represents the benchmark for all future studies of BMI that aim at assessing temporal trends and, thus, the efficacy of national prevention and intervention programs. Regular examinations of certain age groups of children and adolescents in Germany, such as the school entry examinations, can be used for the assessment of temporal trends, if certain standards are followed during the examination. Studies that rely on self-reported height and weight instead of measurements, such as the German part of the HBSC study, however, need a correction based on the subjective body perception. The KiGGS participants themselves are also subject to follow-up interviews and examinations. Thus, it will be possible to regularly update the assessment of the prevalence of overweight and obesity. The Kromeyer-Hauschild reference system should not be replaced by the KiGGS BMI data, in order not to artificially lower the prevalences of overweight and obesity. It should, however, not be used for children below 2 years of age.