- SUBJECTS/METHODS: The study included 5597 boys and 5479 girls aged 7-8 years of age. Socioeconomic status (SES) was defined in three categories: high, medium and low. RESULTS: Between 1966 and 2012, the mean values for height and BMI significantly increased in both sexes (P<0.001). The variation of these two parameters, however, showed a different pattern. Whereas the variation in Z-values for height remained unchanged in both sexes, the variation in BMI increased in boys (P<0.01) but not in girls. SES affected the variation in Z-BMI in 1978 in both sexes (P<0.001), whereas variation in Z-height between SES categories remained unchanged across all years of surveys in boys. Before the political transformation, significant regional differences were observed in the variances of Z-BMI (P<0.05) but not of Z-height. This pattern changed after the political transformation, when regional differences in variances of Z-BMI disappeared. CONCLUSIONS: It is concluded that the mean values and the variation of BMI are affected by a changing qualitySUBJECTS/METHODS: The study included 5597 boys and 5479 girls aged 7-8 years of age. Socioeconomic status (SES) was defined in three categories: high, medium and low. RESULTS: Between 1966 and 2012, the mean values for height and BMI significantly increased in both sexes (P<0.001). The variation of these two parameters, however, showed a different pattern. Whereas the variation in Z-values for height remained unchanged in both sexes, the variation in BMI increased in boys (P<0.01) but not in girls. SES affected the variation in Z-BMI in 1978 in both sexes (P<0.001), whereas variation in Z-height between SES categories remained unchanged across all years of surveys in boys. Before the political transformation, significant regional differences were observed in the variances of Z-BMI (P<0.05) but not of Z-height. This pattern changed after the political transformation, when regional differences in variances of Z-BMI disappeared. CONCLUSIONS: It is concluded that the mean values and the variation of BMI are affected by a changing quality of life, whereas the variation in height is usually independent of living conditions.…
