Ironically—or perhaps tellingly—the heart disease “epidemic” began after a period of exceptionally reduced meat eating. The publication of The Jungle, Upton Sinclair’s fictionalized exposé of the meatpacking industry, caused meat sales in the United States to fall by half in 1906, and they did not revive for another 20 years.

In other words, meat eating went down just before coronary disease took off. Fat intake did rise during those years, from 1909 to 1961, when heart attacks surged, but this 12 percent increase in fat consumption was not due to a rise in animal fat. It was instead owing to an increase in the supply of vegetable oils, which had recently been invented.

Nevertheless, the idea that Americans once ate little meat and “mostly plants”—espoused by McGovern and a multitude of experts—continues to endure. And Americans have for decades now been instructed to go back to this earlier, “healthier” diet that seems, upon examination, never to have existed.