Age differences in physique of adult males aged 30 to 86 years in Rarotonga, the Cook Islands

Abstract

In the Pacific Region, some adult populations have shown a steady rise in overweight and obesity across the 1970s and into the 1990s. While younger adults have been shown to have lower body mass index (BMI) than older ones in both the least and most modernised Samoan populations, among intermediately modernised Samoan populations, BMI has been found to be higher in younger adults than in older ones. A survey in the Cook Islands carried out in 1966 showed no age group differences in height, weight and BMI among adult males, but significantly higher mean weight and BMI among adult males aged 30 years and above. The present analysis gives mean height, weight, BMI and skinfolds of adult males above 30 years of age on Rarotonga in 1996, and examines whether the BMI – age group relationship now shows a similar transitional pattern to that observed on American Samoa. In addition, the 1996 values are compared with values obtained in 1986, to determine whether changes in physique have taken place across this time. In the 1996 volunteer sample of 142 male Cook Islanders, older adults are significantly shorter, lighter, with lower BMI than younger adults. Furthermore, the younger adults of the 1996 survey are significantly heavier, with greater BMI than the 1986 sample. This suggests that the adult male Rarotongan population is in an intermediate position with respect to lifestyle transition, the secular trend in body size and increasing prevalence of obesity, and that there has been a rapid increase in body fatness prevalence among younger adults.