Measurements
Childhood obesity was determined using the weight and
height measurements and classified as a weight-for-height
greater than + 2.0 Z-scores of the NCHS reference
population.31 This method was chosen because it is relatively
non-invasive and inexpensive, reflecting body weight relative
to height, thus more closely reflecting body fatness than other
methods. It is sensitive to current nutritional status and
relatively independent of ethnicity and age in pre-pubertal
children. It is the method of measuring childhood obesity
recommended by the World Health Organisation.1
A standard measurement routine was established. The
first researcher weighed each child once on Seca digital
scales (SECA 220/220 000, Mess - und Wiegetechnik. Vogel & Halke
BmbH & Co. P.O.B. 76 11 80. 2000 Hamburg 76. tel: 040/20 0000-0, fax:
040/20 0000 50) to the nearest 0.1 kg (the subjects being in light
clothes with emptied pockets and without shoes). The second
researcher would take height measurements using standard
methods of each child twice with the wooden stadiometer
(locally constructed PTU-KKU, Thailand) without shoes to
the nearest 0.1cm. The children stood straight with their
heels, shoulders and backsides against the vertical plank and
their head was in the Frankfurt plane (the line from the hole
in the ear to the bottom of the “orbit” i.e. bone of the eye).32
The third researcher recorded weight and height data on the
recording form. Tasks were rotated on a daily basis between
the three researchers. The calibration of the anthropometric
equipment was checked at each new location and after long
breaks at the sites.