 Considering its epidemic-like development worldwide, associated with modifications in lifestyle, as well as its enormous social and economic weight, the prevention of type II diabetes is certain to be a central concern of health systems within the developed countries in the decades to come. However, while simple obesity concerns the entire population, type 2 diabetes affects only one sub-population at high genetic risk. To be effective and realistic in economic terms, efforts at prevention must be thus targeted towards these subjects at high risk. The key issue involves identifying such subjects early enough so that a strategy of effective prevention can be organized in good time. 