Thus, in a causal web, disease events are influenced by risk factors both directly and indirectly. The definition of the risk factors, as well as the thresholds used to identify individuals at risk, is largely based on data provided by the WHO Comparative Quantification of Health Risks publication (Ezzati, Lopez, Rodgers, & Murray, 2004). In the model, proximal risk factors, such as high blood pressure, high cholesterol, and high blood glucose, have a direct influence on the probability of developing such chronic diseases. This accounts for the effect of known pathophysiological mechanisms. Conversely, distal risk factors, such as low intake of fruit and vegetables, high fat intake, and insufficient physical activity, have an indirect influence on chronic diseases.