Prevalence of overweight and obesity and trends in body mass index in German pre-school children, 1982-1997

OBJECTIVE: To examine the prevalence of overweight and obesity in the entire population of 5- and 6-y-old children entering school in Germany, Bavaria, and to assess time trends over the last 15y and the impact of ethnicity. DESIGN: Cross-sectional studies were based on the obligatory school entry health examinations: all health districts of Bavaria in 1997 (n=127 735); three health districts every 5y from 1982 to 1997 (n=16 281). MEASUREMENTS: Body mass index (BMI; kg/M-2) was calculated and the prevalence of overweight and obesity was defined based on national and international agreed cut-off points. Ethnicity was measured as German and non-German nationality. RESULTS: The prevalence of overweight and obese children as defined by international reference values was 9.4 and 3.1% for 5-y-old boys, 10.0 and 2.9% for 6-y-old boys, 12.2 and 3.3% for 5-y-old girls and 12.4 and 3.3% for 6-y-old girls. The whole BMI distribution in non-German children compared to German children was shifted to the right with median values in non-German children 0.3-0.5 kg/m(2) higher. In these the prevalence of overweight/obesity was 1.9/2.4 times higher for boys and 1.5/1.9 times higher for girls. The time trend between 1982 and 1997 shows an increase of the BMI distribution in the upper percentiles, whereas the lower percentiles did not change substantially. The increased prevalences of overweight/obesity for both sexes as defined by international references increased from 8.5/1.8% in 1982 to 12.3/2.8% in 1997. CONCLUSION: This large study on all children entering school in Bavaria in 1997 shows patterns of overweight and obesity which are comparable with other European data but are lower than US and Australian data. Increasing prevalences since 1982 indicate that overweight and obesity in children are of increasing public health importance in Bavaria. The upwards shift of the BMI distribution in non-German children needs further investigation.