Background: Obesity increases the risk of cardiovascular diseases and diabetes. Objective: To determine which measure of adiposity, body mass index (BMI), waist circumference (WC) or body fat mass (BFM) is the most predictive of the coronary heart disease (CHD) risk and of the presence of the metabolic syndrome. Methods: A cross-sectional study of 649 consecutive Men and women aged 22-79 years, in primary prevention. Results: BMI, WC and BFM were strongly associated with Conventional cardiometabolic risk, factors. For a l-S.D. increase in BMI, WC and BFM. the odds ratios (95% CIs) of having the metabolic syndrome after adjustment for age, gender, and drug treatments were as follows: BMI, 3.40 (2.68-4.37): WC. 4.79 (3.61-6.53); and BFM, 3.19 (2.49-4.16). WC annihilated the association of BMI and BFM with the metabolic syndrome Mien measures Of adiposity were introduced two by two. For CHD risk. the odds ratios (95% CIs) were as follows: 1.62 (1.16-2.24), 1.7-2 (1.22-2.4-1). and 1.92 (1.40-2.62) respectively. BFM annihilated the associations of BMI and WC with CHD risk when measures of adiposity were introduced two by two. Conclusions.. WC shows the best association with the metabolic syndrome. while BFM shows the best association with high CHD risk. BMI shows weaker relationships with the metabolic syndrome, and high CHD risk. Our findings suggest that BFM can be used as a complementary measure to identity CHD risk in adult subjects. (C) 2007 Elsevier Ireland Ltd. All rights reserved.