Measurements were conducted in school nurses' offices from 8:00 am to 3:00 pm. All measurements were taken in duplicate by trained staff: anthropologists, nurses, public health professionals, and physicians using standard, calibrated equipment. Each study team consisted of two professionals. The exact ages of the participants were calculated from birth and examination dates.
Height was measured using a SECA 214 stadiometer. The subject was in the standing upright position (no shoes), with hips and shoulders perpendicular to the central axis, heels against the footboard, knees together, arms hanging loosely at the sides, and the head in the Frankfurt plane. Height was recorded to the nearest millimeter; if the difference between measurements exceeded 4 mm, a third measurement was taken. Body weight was recorded in light underwear to the nearest 0.05 kg, using a digital medical scale (Radwag WPT 100/200, Poland). In the case of a difference between measurements equal to or exceeding 0.3 kg, a third measurement was taken. Body mass index was calculated as body weight divided by height in meters squared.
Height was measured using a SECA 214 stadiometer. The subject was in the standing upright position (no shoes), with hips and shoulders perpendicular to the central axis, heels against the footboard, knees together, arms hanging loosely at the sides, and the head in the Frankfurt plane. Height was recorded to the nearest millimeter; if the difference between measurements exceeded 4 mm, a third measurement was taken. Body weight was recorded in light underwear to the nearest 0.05 kg, using a digital medical scale (Radwag WPT 100/200, Poland). In the case of a difference between measurements equal to or exceeding 0.3 kg, a third measurement was taken. Body mass index was calculated as body weight divided by height in meters squared.
