White flour and sugar were singled out as particularly noxious, because these had been increasing dramatically in Western diets during the latter half of the nineteenth century, coincident with the reported increase in cancer mortality. (They would also be implicated in the growing incidence of diabetes, as we’ll discuss, and appendicitis.) Moreover, arguments over the nutritive value and appeal of white flour and sugar had been raging since the early nineteenth century.

Flour is made by separating the outer layers of the grain, containing the fiber—the indigestible carbohydrates—and virtually all of the vitamins and protein, from the starch, which is composed of long chains of glucose molecules. White sugar is made by removing the juice containing sucrose from the surrounding cells and husk of the cane plant or sugar beet. In both cases, the more the refining, the whiter the product, and the lower the vitamin, mineral, protein, and fiber content. The same is true for white rice, which goes through a similar refining process.

This might seem obviously disadvantageous, but white flour had its proponents. It was traditionally considered “more attractive to the eye,” as Sir Stanley Davidson and Reginald Passmore observed in their textbook Human Nutrition and Dietetics (1963). It was preferred by bakers for its baking properties, and because it contains less fat than wholemeal flour it is less likely to go rancid and is more easily preserved. Millers preferred it because the leftover bran from refining rice and wheat (as with the molasses left over from refining sugar) could be sold profitably for livestock feed and industrial uses. Nutritionists also argued that white flour had better “digestibility” than whole-meal, because the presence of fiber in the latter prevented the complete digestion of any protein or carbohydrates that were attached. White flour’s low protein, vitamin, and mineral content also made it “less liable than whole meal flour to infestation by beetles and the depredation of rodents,” as Davidson and Passmore wrote.

It wasn’t until the mid-nineteenth century that white flour became suitably inexpensive for popular consumption, with the invention of roller mills for grinding the grain. Until then, only the privileged classes ate white flour, and the poor ate wholemeal. Sugar was also a luxury until the mid-nineteenth century, when sugar-beet cultivation spread throughout the civilized world. In 1874, with the removal of tariffs on sugar importation in Britain, sugar consumption skyrocketed and led to the eventual development of the biscuit, cake, chocolate, confectionery, and soft-drink industries. By the beginning of World War I, the English were already eating more than ninety pounds of sugar per capita per year—a 500-percent increase in a single century—and Americans more than eighty pounds. Not until the mid-twentieth century did mechanical rollers begin replacing hand-pounding of rice in Asian nations, so that the poor could eat polished white rice instead of brown.