Overweight and obesity epidemic among children. Answer from European countries.

Objective: To investigate the methods and results used and conclusions found in available published papers on childhood overweight and obesity in Europe.

Surveys: This paper compares the two available published papers on the prevalence of child and adolescent overweight and obesity in Europe. The first paper was published in November 2003 and was based on 20 previously conducted surveys performed from 1992 to 2001. The other paper was published in January 2004 and was based on data from the WHO collaborative survey 'Health Behaviour in School Children', which collected the data in 1997-1998 within a period of 9 months. Height and weight were included as optional questions and 13 European countries, Israel and United States participated.

Methods: In both papers, body mass index (BMI) was used. In the first paper, measured BMI was used and prevalence of overweight was calculated using IOTF cutoff points. In the other paper, overweight and obesity prevalences were calculated from self-reported height and weight using an internal study reference standard.

Results: The first paper found a north-south trend in overweight in Europe, whereas the second found a more equal distribution of overweight in European children. Thus, overweight was significantly increased among 13 y olds of both sexes in Finland, Ireland, and Greece, and in Portuguese girls. Among 15 y olds, the prevalence of overweight was significantly increased in Greek boys, and in Danish and Portuguese girls. On the contrary, in Lithuania, there was a significantly low prevalence of overweight among both ages and both sexes.

Conclusion: Critical reviews of the results of the two published papers show that the year of data collection, methods and use of appropriate statistics are of critical importance for the conclusion drawn from comparative epidemiological surveys on the prevalence of overweight.