After the Second World War, Western countries were faced with a growing burden of cardiovascular disease (CVD) and cancer, seen then as "diseases of affluence". Classical studies soon identified a few strong and obviously causal risk factors for CVD, especially high serum cholesterol, high blood pressure and smoking (l). Smoking was shown as strong cause of many cancers. It was realized that unlike previous public health problems with communicable diseases, the risk factors are strongly related to certain behaviours.