Recommendations to Americans concerning dietary fat and heart disease began to appear in the late 1950s. This followed the publications of Gofman et al. (1950) and Keys (1953) relating to techniques for separating plasma lipoprotein fractions and the epidemiologic correlations between dietary fat, serum cholesterol and heart disease, respectively. Advice to the public after 40 years is similar to that given originally, namely, to reduce total fat, saturated fat and cholesterol intake, although cholesterol intake per se is not correlated strongly with cholesterolemia. Newer players on the heart disease stage are homocysteinemia, chlamydia infection and cytomegalovirus. These findings, when amplified, may alter the thrust of medical and dietary advice. In the meantime, since 1950, deaths from all causes in the U.S. (per 100,000, age-adjusted) have fallen by 40% and deaths from heart disease and stroke have fallen by 53 and 70%, respectively.