Body mass index, waist hip ratio, and waist circumference: which measure to classify obesity?

Objectives: To determine the proportion of a representative population sample of adults in South Australia who have a body mass index (a measure of overall obesity) classified as normal or underweight, but who also have a waist circumference or waist hip ratio (measures of central obesity) that indicates obesity. Methods: A representative population sample of adults aged 18 years and over living in the north west region of Adelaide (n = 2523) were recruited to the study. Clinical measures of height, weight, waist and hip circumference were obtained and used to determine body mass index, waist hip ratio and waist circumference. Results: Among women with a normal body mass index, 19.0% had a high waist circumference (greater than or equal to80 cm) and 8.5% had a high waist hip ratio (>0.85). Among males with a normal body mass index, 3.4% had a high waist circumference (greater than or equal to95 cm) and 0.1% had a high waist hip ratio (>1.0). Conclusions: Body mass index, waist hip ratio and waist circumference all have a role in the identification of those who are obese or overweight.