Comparison of weight and height relations in boys from 4 countries

Height and weight data from children in the United States, United Kingdom, Japan, and Singapore were analyzed to investigate differences in growth bet ween the groups of children. An investigation into the adjusted weight inde xes of the form index = weight/height(p) for differing powers of p (Benn in dex) showed that the power of p required to produce a correlation of zero b etween the index and height varied with age. For the United States, Japan, and Singapore the p Value was just below 3.0 for children aged 6 y, increas ed to approximate to 3.5 for children aged approximate to 10 y, and decreas ed to approximate to 2.0 at age approximate to 18 y. A consequence of the p value being mostly >2.0 is that BMI (wt/ht(2)) tends to be greater for tal l children than for short children. The US data (from the second National H ealth and Nutrition Examination Survey) also contained information on skinf old thickness. Relating skinfold thickness to indexes of the same farm for height and weight suggested that the best relation was achieved with p valu es of approximate to 2.0 except for children aged 12-16 y, for whom the opt imal values for p were higher. The highest value, 2.9, was achieved at ages 12-13 y. Overall, the use of BMI as an indicator of adiposity appears acce ptable for children aged 6-7 and 17-18 y. However, BMI should be used with caution when assessing children aged 8-16 y.