This belief in the fattening powers of carbohydrates can be found in literature as well. In Tolstoy’s Anna Karenina, for instance, written in the mid-1870s, Anna’s lover, Count Vronsky, abstains from starches and sweets in preparation for what turns out to be the climactic horse race. “On the day of the races at Krasnoe Selo,” writes Tolstoy, “Vronsky had come earlier than usual to eat beefsteak in the officers’ mess of the regiment. He had no need to be in strict training, as he had very quickly been brought down to the required weight of one hundred and sixty pounds, but still he had to avoid gaining weight, and he avoided starchy foods and desserts.” In Giuseppe di Lampedusa’s The Leopard, published in 1958, the protagonist, Prince Fabrizio, expresses his distaste for the plump young ladies of Palermo, while blaming their condition on, among other factors, “the dearth of proteins and the overabundance of starch in the food.”

This was what Dr. Spock taught our parents and our grandparents in the first five decades, six editions, and almost 50 million copies of Baby and Child Care, the bible of child-rearing in the latter half of the twentieth century. “Rich desserts,” Spock wrote, and “the amount of plain, starchy foods (cereals, breads, potatoes) taken is what determines, in the case of most people, how much [weight] they gain or lose.” It’s what my Brooklyn-born mother taught me forty-odd years ago. If we eat too much bread or too much spaghetti, we will get fat. The same, of course, is true of sweets. For over a century, this was the common wisdom. “All popular ‘slimming regimes’ involve a restriction in dietary carbohydrate,” wrote Davidson and Passmore in Human Nutrition and Dietetics, offering this advice: “The intake of foods rich in carbohydrate should be drastically reduced since over-indulgence in such foods is the most common cause of obesity.” “The first thing most Americans do when they decide to shed unwanted pounds is to cut out bread, pass up the potatoes and rice, and cross spaghetti dinners off the menu entirely,” wrote the New York Times personal-health reporter, Jane Brody, in her 1985 best-selling Good Food Book.