Body size and composition in Polynesians

OBJECTIVES: To compare the relationship between body size and body composit ion in New Zealanders of Polynesian and European descent and to develop spe cific regression equations for fat mass for Polynesians. SUBJECTS: 189 Maori (93 males, 96 females), 185 Samoans (88 males, 97 femal es) and 241 Europeans (89 males, 152 females) aged 20 - 70 y. MEASUREMENTS: Height, weight, four skinfold thicknesses, bioelectrical impe dance analysis (BIA) and dual energy X-ray absorptiometry (DXA). RESULTS: At higher body mass index levels, Polynesians (Maori and Samoans c ombined) had a significantly higher ratio of lean mass:fat mass compared wi th Europeans. Four multiple regression equations incorporating resistance a nd reactance, height and weight, sum of four skinfolds or sum of two skinfo lds were developed in two-thirds of the Polynesian participants using DXA f at mass as the dependent variable. In the remaining one-third of participan ts, the mean difference between fat mass predicted by these equations (r(2) range 0.89 - 0.93) and DXA fat mass ranged from - 0.06 to + 0.25 kg (s.d. - 3.67 to + 3.71 kg), CONCLUSION: At higher BMI levels, Polynesians were significantly leaner tha n Europeans, implying the need for separate BMI definitions of overweight a nd obesity for Polynesians. The regression equations using BIA, height and weight or skinfold thicknesses were good predictors of body composition in Polynesians.