ABSTRACT
Causal networks and Bayesian networks were devised in the 1980s. Causal networks have a value for those who are less mathematically inclined, because they introduce a new diagrammatic way of representing causal relations, and this is very helpful, especially in dealing with indeterministic causes. It is perfectly legitimate to illustrate the casual factors in heart disease by the type of multi-causal fork. Ancel Keys was anxious to apply the new hypothesis in order to reform the American diet, and make Americans healthier and less liable to coronary heart disease (CHD). Curiously in the seven countries study, Keys did not find that body mass and fatness were causal factors for coronary heart disease. This is probably because no one in his cohorts reached the levels of overweight/obesity which are common today. The chapter establishes that the causal law: eating fast food → heart disease is very well confirmed empirically, and can consequently be used as a basis for action.
