Anthropometry

Anthropometric data was assessed at the Tanner B4 visit by a trained dietitian using standardized protocols (ICC ≥ 0.75)³³. Weight was measured with a portable scale, SECA model 770 (capacity of 200 kg precision of 0.1 kg); height was measured with a stadiometer, HARPENDER model 603 (capacity 200 cm, sensitivity 0.1 cm); and waist circumference, defined as the midpoint between the last rib and the iliac crest, was measured with a tape, LUFKIN W606PM (capacity 200 cm and precision 0.1 cm). We defined central obesity as a WC > the 90^th percentile according to age of the girls (9 to 13 y). The cutoff points for WC > the 90^th percentile according to NHANES III were 73.6, 76.6, 79.7, 82.7, and 85.8 cm for girls from 9 to 13 y old, respectively. Body mass index (BMI) was calculated as weight (kg)/height² (m²), and we estimated the BMI Z-score according to the 2007 World Health Organization (WHO) data³⁸.

BW was collected retrospectively from clinical records, and the quality of the BW data has been previously evaluated, indicating <1% implausible values (GOCS protocol)³⁹.