Trained staff conducted the anthropometric measurements of the children according to ISAK-standards . The children’s height was measured to the nearest 0.1 cm (Stadiometer, Seca®, Germany), and body weight to the nearest 0.1 kg using calibrated and balanced portable digital scales (Seca®, Germany). Waist circumference (WC) was measured midway between ileac crest and lower costal arch to the nearest 0.1 cm using a flexible metal tape (Lufkin Industries Inc., Texas, USA). The children’s BMI was calculated as weight divided by height squared [kg/m2]. Excess weight and obesity were defined at or above the 90th and 97th age- and gender-specific BMI percentiles according to German reference data . Waist- to-height ratio (WHtR) was calculated as the ratio of WC and height in centimeters, participants with a WHtR ≥ 0.5 were then categorized as abdominally obese . Because there was some doubt the WHtR threshold of 0.5 was sensitive enough, a lower threshold (0.47 for girls and 0.48 for boys) as proposed by Nambiar et al. , correlating with the 95th percentile for %body fat, was added.