All clinicians must have a measuring tape on their desk. This is as important as having a blood pressure metre and scales in their office. If the metabolic syndrome is suspected, waist circumference must be measured. This must be done in patients at high risk, see Fig. 15.1. If increased waist circumference is measured, serum triglyceride, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and fasting plasma glucose must also be measured. Based on these measurements, the diagnosis “metabolic syndrome” can be made, and a formal basis for intervention is obtained. The International Diabetes Federation (IDF) has recently formulated a definition of the metabolic syndrome, and we recommend using this definition in clinical practice [1].