A comparative study of methods for diagnosis of obesity in an urban mixed-race population in Minas Gerais, Brazil.

BACKGROUND Obesity is defined as an excess of total body fat and may be assessed by different methods. The objective of the present study was to establish the discriminatory power of anthropometric data in determining obesity. METHODS The subjects comprised 685 individuals, aged 20-79 years, sampled from a population-based survey. The following indicators were used: body mass index (BMI), waist circumference (WC) and total body fat percentage estimated with both Siri's equation (%BF Siri) and foot-to-foot bioelectrical impedance analysis (%BF BIA). Sensitivity and specificity of different cut-off points for each method were determined using %BF BIA as reference. RESULTS Of 685 participants, 57.6% were aged >/= 40 years, 69.9% were women and 72.6% self-referred themselves as non-white. To classify obesity based on sex and age among women aged 0.05). Classifying according to skin colour did not change cut-off points in any indicator. CONCLUSION BMI and WC better discriminate obesity among women and men aged >/= 40 years from a mixed-race population.