Trend of Body Mass Index Movement of Primary School Students Over a 15 - Year Period

Sa？etak The aim of this study was to describe the trend of median body mass index (BMI) in students from the fifth to the eighth grade in a primary school in Zagreb in the period from 1999 to 2014. The sample consisted of students (N=3.567; 1.652 female and 1.915 male students) from the fifth to the eighth grade of primary school in the city of Zagreb, chronological age of 12 to 15 years. BMI was defined at the beginning of the school year on the basis of the collected data on body mass and body height of the students. This method was used as an indicator of their nutritional status. Regression analysis was used in order to review the trend of BMI. The results have shown that among the majority of the classes an increase in BMI was visible, but it was statistically significant only in the male students of the sixth and seventh grade. The regression analysis of the sixth graders showed a statistically significant (p=0.019) increase of the median of BMI (0.08 kg/m2 per year) during the period of research. As for the seventh graders, there was a statistically significant (p=0.004) increase in the median of BMI (0.14 kg/m2) per year