Body mass index trend as a new parameter for evaluating children's nutritional status

The objective was to identify a body mass index (BMI) trend as a new indicator and predictor of children's nutritional status, replacing absolute BMI, and to demonstrate that a local BMI trend is more appropriate for this purpose than a national (or international) BMI trend. An entire school year group of primary school children were subject to a longitudinal 8-year cohort study. BMI was measured three times during primary school education—on enrolment to primary school, then in the fifth and eighth grades. The BMI values obtained were used to create gender- and age-based percentile curves for children born in 1998/1999 (Osijek Percentile Curves (OPC) study) in the Osijek-Baranja County, Croatia. Every BMI result obtained was linked to one of the five percentile ranks (PRs) according to threshold percentiles 3, 10, 90 and 97; hence, the PRs were