It may be true that meat consumption was relatively low in the first decade of the twentieth century, but this may have been a brief departure from the meat-eating that dominated the century before. The population of the United States nearly doubled between 1880 and 1910, but livestock production could not keep pace, according to a Federal Trade Commission report of 1919. The number of cattle only increased by 22 percent, pigs by 17 percent, and sheep by 6 percent. From 1910 to 1919, the population increased another 12 percent and the livestock lagged further behind. “As a result of this lower rate of increase among meat animals,” wrote the Federal Trade Commission investigators, “the amount of meat consumed per capita in the United States has been declining.” The USDA noted further decreases in meat consumption between 1915 and 1924—the years immediately preceding the agency’s first attempts to record food disappearance data—because of food rationing and the “nationwide propaganda” during World War I to conserve meat for “military purposes.”

Another possible explanation for the appearance of a low-meat diet early in the twentieth century was the publication in 1906 of Upton Sinclair’s book The Jungle, his fictional exposé on the meatpacking industry. Sinclair graphically portrayed the Chicago abattoirs as places where rotted meat was chemically treated and repackaged as sausage, where tubercular employees occasionally slipped on the bloody floors, fell into the vats, and were “overlooked for days, till all but the bones of them had gone out to the world as Anderson’s Pure Leaf Lard!” The Jungle caused meat sales in the United States to drop by half. “The effect was long-lasting,” wrote Waverly Root and Richard de Rochemont in their 1976 history Eating in America. “Packers were still trying to woo their customers back as late as 1928, when they launched an ‘eat-more-meat’ campaign and did not do very well at it.” All of this suggests that the grain-dominated American diet of 1909, if real, may have been a temporary deviation from the norm.

The changing-American-diet argument is invariably used to support the proposition that Americans should eat more grain, less fat, and particularly less saturated fat, from red meat and dairy products. But the same food-disappearance reports used to bolster this low-fat, high-carbohydrate diet also provided trends for vegetables, fruits, dairy products, and the various fats themselves. These numbers tell a different story and might have suggested a different definition entirely of a healthy diet, if they had been taken into account. During the decades of the heart-disease “epidemic,” vegetable consumption increased dramatically, as consumption of flour and grain products decreased. Americans nearly doubled (according to these USDA data) their consumption of leafy green and yellow vegetables, tomatoes, and citrus fruit.