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.