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 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