Metabolic syndrome is associated with abdominal obesity, blood lipid disorders, inflammation, insulin resistance or full-blown diabetes, and increased risk of developing cardiovascular disease. Proposed criteria for identifying patients with metabolic syndrome have contributed greatly to preventive medicine, but the value of metabolic syndrome as a scientific concept remains controversial. The presence of metabolic syndrome alone cannot predict global cardiovascular disease risk. But abdominal obesity - the most prevalent manifestation of metabolic syndrome - is a marker of 'dysfunctional adipose tissue', and is of central importance in clinical diagnosis. Better risk assessment algorithms are needed to quantify diabetes and cardiovascular disease risk on a global scale.