Comparison of United States and New Zealand Children's Body Mass Scores

Abstract

Body Mass Index (BMI) scores were calculated for two racially similar samples, one from New Zealand and the other from the United States, at ages 3, 5, 7 and 13 years. At ages 3, 7 and 13 years, the New Zealand subjects had higher BMI scores than their American peers. Chi-square analyses showed that a disproportionately large number of American subjects had scores in the bottom 20th percentile for their age and sex than expected at each of the four ages. Similarly, a disproportionately larger number of New Zealand subjects had BMI scores in the uppermost 20th percentile at ages 3 and 13 years. It is hypothesized that the difference in BMI scores for the two samples, which have previously been shown to have similar median heights and weights, reflects a difference in degree of body fat.