The Seven Countries Study is an epidemiological longitudinal study directed by Ancel Keys at what is today the University of Minnesota Laboratory of Physiological Hygiene & Exercise Science (LPHES). Begun in 1956 with a yearly grant of US$200,000 from the U.S. Public Health Service, the study was first published in 1978 and then followed up on its subjects every five years thereafter.
As the world's first multicountry epidemiological study, it systematically examined the relationships between lifestyle, diet, coronary heart disease and stroke in different populations from different regions of the world. It directed attention to the causes of coronary heart disease and stroke, but also showed that an individual’s risk can be changed.
As of 2016, heated scientific debate continues. Project officer Henry Blackburn wrote in 1975, "Two strikingly polar attitudes persist on this subject, with much talk from each and little listening between." Ian Leslie quotes a sympathetic colleague at the University of Minnesota who said Keys was "critical to the point of skewering”.
