In the past 25 years, obesity and diabetes mellitus have overtaken cigarette smoking, dyslipidemia, and hypertension as risk factors for coronary heart disease. Data from a Centers for Disease Control and Prevention (CDC) survey of 50 states revealed that, in 2000, the prevalence of obesity among US adults was approximately 20%, a 61% increase from the 1991 prevalence rate. Currently, most adults (> or =56%) are overweight, approximately 1 in 5 is obese, and 7.3% have diabetes. Overweight and obesity increase the risk for hospitalization and death from cardiovascular disease (CVD) and type 2 diabetes at all levels of risk and independently of other risk factors. In particular, abdominal obesity (assessed indirectly by measuring waist circumference) may be associated with clustering of cardiovascular and metabolic risk factors (i.e., hypertriglyceridemia, low high-density lipoprotein [HDL] cholesterol levels, high blood pressure, and elevated levels of fasting glucose) known as the metabolic syndrome. Patients with even minimal abnormalities in any 3 of the 5 risk factors for the metabolic syndrome are at heightened risk for CVD or diabetes. It is estimated that 47 million US adults, 25% of the population, have > or =3 metabolic syndrome components. Abdominal obesity is the most common, followed by low HDL cholesterol levels, high blood pressure, and high levels of triglycerides. The risk for disease increases over time as the number of metabolic syndrome characteristics accumulates; therefore, early intervention is warranted. Given the prevalence and potentially deadly consequences of the metabolic syndrome, it is imperative for physicians to recognize the presence of these risk factors in their patients and to familiarize themselves with the recommended treatment strategies.