Was Ancel Keys responsible for the modern epidemic of obesity?If you have read any low carb blog lately, you would think so.Their revisionist history is broken down to this:Ancel Keys was an influential scientist who thought fat was to blame for heart diseaseHe did a study of diet and correlated fat and heart disease in those people of the seven countriesBut Dr. Keys left out countries that would have proven his hypothesis wrongThe influence of Dr. Keys work turned the US away from saturated fat and to sugarSugar causes obesity and all the lifestyle illness of the worldDr. Keys brought us snackwells instead of pork rinds and we are all obese with diabetesYou will find versions of this in blogs, books, and videos.  Low-carb bloggers plagiarize one another. Nor have they never the primary source material.The Mediterranean Diet Founder and the StudyKeys is the founder of the Mediterranean Diet. He was a pioneer physiologist, one of the first to show that diet was an important component of heart disease.In the 1950's few considered diet an important component of heart disease.Rich People and Diets"In 1952 when Margaret and I were making surveys in Naples and then Madrid. It seemed quite clear that there was some relationship between diet and the incidence of coronary heart disease. Rich people had different diets and different blood cholesterols, and they had the only heart attacks in town. When those findings were written up and presented at a meeting in Amsterdam, some people were impressed and some didn't believe anything about it. " - Ancel KeysThis early observation by Keys  was the impetus for  the Seven Country Study.That diet was responsible for heart disease was contrary to the prevailing theory: in the 1950's heart disease was hypothesized to be phenomenon of aging.  Dr. Keys meticulous research revealed the strong correlation between heart disease and a diet rich in saturated fat.The First GraphThe graph below is a result of looking at macro dietary statistics of a country compared with death rates from heart disease. Keys presented this data at a WHO meeting in the early 1950's. The conclusion about fat and heart disease,  was met with a great deal of skepticism. Diet was not considered a factor in heart disease.While this data points to a potential cause, to examine this hypothesis one must perform a cohort study.Some assume that Keys collected country wide data about diet and heart disease, but he did not. Bloggers probably assume this based on this graph, as well as the name, Seven Countries Study. But the Seven Country Study was far more precise. The Study was a Cohort type study.Cohort StudiesA cohort study follows subjects for a long period of time. The Seven Countries Study followed over 12,000 men for nearly 50 years.Following these men involved yearly physical examinations, blood work, hospital and death records, as well as very specific dietary follow up.Of all the factors examined, saturated fat and blood cholesterol were most correlated with  heart disease.One of the more common myths about the Seven Country Study was that sugar was not examined. In fact, sugar was examined as an independent dietary factor. Sugar was not an primary variable for heart disease, unless combined with saturated fat.Testing both low and high fat countriesThe low-carb bloggers assume that Keys only tested those countries whose diet was rich in carbs, and low in fat. Keys chose his cohorts based on different diets, from those who were low fat, to high fat. Total fat, as it turns out, was not a factor for heart disease. Greeks