[Status-specific differences in the occurrence of overweight and obesity in the transitional period from childhood to adolescence - results from the cross-sectional German KiGGS study].

BACKGROUND: Individual studies point out that health inequalities decrease in the transitional period from childhood to adolescence. However, there is evidence that this effect can vary depending on the health aspect that is used. The present study analyses this effect for overweight and obesity.

METHODS: Representative data was obtained from a subsample (3-17 years, n=14,836) of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) which was conducted by the Robert Koch Institute from May 2003 to May 2006. Body height and weight were measured and body mass index (BMI) was calculated. Overweight and obesity are defined based on gender- and age-specific percentiles of BMI of the German reference system developed by Kromeyer-Hauschild and her colleagues. Socio-economic status (SES) was taken from information about parents' income, occupational status and education.

RESULTS: Boys and girls with low SES show the highest prevalence of overweight and obesity in all age groups, those with high SES the lowest. While the results indicate a constant impact of SES on the risk for overweight and obesity in boys, the status differences increase over the age groups in girls. Regarding the whole age range, boys with low SES possess a 2.0-fold increased risk for overweight, and a 2.2-fold increased risk for obesity compared to boys with high SES. Girls from low status group even have a 2.8-fold risk to become overweight, and a 4.4-fold risk to become obese in comparison to the reference group.

CONCLUSION: The findings reveal that SES has a significant impact on the occurrence of overweight and obesity in childhood and in particular adolescence. Therefore, the results underline the relevance of early childhood prevention in specific target groups and promotion of a healthy life style.