Relation of adiposity and body fat distribution to body mass index in Australians of Aboriginal and European ancestry.

Abstract

To compare the relations of adiposity and body fat distribution to body mass index (BMI) in Australians of Aboriginal and European ancestry. Cross-sectional volunteer samples. Australian Aboriginal communities in remote central and northern Australia, urban European Australians resident in Melbourne, Australia. Healthy Aboriginal (130 women, 120 men) and European Australians (100 women, 47 men) with a BMI<30 kg/m(2), aged 18-35 y; all women were nonpregnant. Anthropometric variables and resistance-using a four-terminal impedance plethysmograph-were measured. Aboriginal women and men were significantly shorter and weighed less than European Australians (P<0.05). Aboriginal women had a significantly larger waist circumference and waist-to-hip ratio (WHR, P<0.0005) compared to European Australian women. The sum of four skinfold thicknesses (SFT) (S4) and trunk SFT was higher in Aboriginals as compared to European Australian women (P<0.0005); however, limb SFT tended to be lower (P=0.06). On the other hand, BMI was significantly lower in Aboriginals compared to European Australian men (P=0.011), as was hip circumference (P=0.001); however, WHR was significantly (P=0.007) higher. On regression analysis, Aboriginal women and men were significantly heavier than European Australians for the same height(2)/resistance (surrogate for fat-free mass) and S4 (surrogate for subcutaneous fat); and that Aboriginal men had a significantly higher BMI (by 1.2 kg/m(2); P<0.0005) for any given S4 and height(2)/resistance values, compared to European Australian men. Aboriginal and European Australians have a significantly different body fat distribution and fat mass for a given body weight or BMI. Use of the World Health Organization recommended BMI ranges to determine weight status may be inappropriate in Australian Aboriginal people.