New Zealanders of Polynesian origin have a higher prevalence of obesity and type 2 diabetes mellitus than those of European origin. Risk factors for type 2 diabetes mellitus--decreased energy expenditure, increased body fat mass, and central body fat--in 30 normoglycemic Maori, Pacific, and European men were studied. Biochemical measures of risk for type 2 diabetes mellitus included an oral glucose tolerance test, insulin, lipids, and glycosylated hemoglobin. The groups did not differ significantly in BMI, height, body mass or fat mass (DEXA), or adjusted resting metabolic rate (indirect calorimetry), but the European subjects had significantly lower subscapular to triceps skinfolds and fat-free mass than the Maori and Pacific groups. Central obesity by anthropometry and DEXA showed strong associations with the biochemical measures for type 2 diabetes risk. These findings emphasize the association between body composition and central fat distribution with risk of diabetes independent of ethnicity.