Reducing the risk factors that diseases have in common may prove to be an efficient prevention strategy (1 - 2). For example, major risk factors, including obesity, physical inactivity, smoking, hypertension, hyperglycemia, and hyperlipidemia, predict the development of several chronic diseases, such as cardiovascular disease, cancer, diabetes, and dementia (3 - 5). Although one risk factor may confer a greater risk for a certain disease outcome than another risk factor, these risk factors are correlated and seem to operate in concert. A successful preventive intervention must, therefore, target several risk factors simultaneously (2,6). This characteristic of preventive interventions means that they are necessarily complex and require considerable resources.