The problem of atherosclerosis, America's number one killer (810,000 deaths in 1955), has become within recent years also the most exciting medical study. Whereas for years it was thought to be merely a degenerative disease and a part of the inevitable process of aging, it now occupies the front line in research effort. Ancel Keys, more than any other one person, has stirred the medical profession to think of this "disease" as a progressive process, probably preventable and maybe reversible. It is present in epidemic proportions in the U. S. A. His concept of a "world look" at this problem has caught the imagination medically, much as Willkie's "One World" did politically. Keys and Anderson1showed that the people in Italy eating a low-fat diet have little atherosclerosis and coronary disease. The people in Spain also have little atherosclerosis on low fats, whereas the wealthy in Spain, who eat