It is also vital to understand that it’s our cells and tissues that require and expend the energy we consume, so this adjustment of intake to expenditure is occurring first and foremost on a cellular level. “Whatever may be the mechanisms controlling food intake,” as the University of California, Berkeley, nutritionist Samuel Lepkovsky wrote in 1948, “the chief site of their action must be the cell.” A fundamental requirement of any living organism is to provide a steady and reliable supply of fuel to its cells, regardless of the circumstances. We apparently evolved an intricate and extraordinarily robust regulatory system of hormones, enzymes, and the nervous system to accomplish this task. If the necessary fuel fails to reach the cells, the body compensates. The crucial factor is not how much is eaten—how many calories are consumed—or how much is expended, but how those nutrients or the energy they contain is ultimately distributed, how those calories are utilized and made available when needed. It’s not the energy balance that is driving this system, but the distribution of that energy, the demand for energy at the cellular level.

Chapter 18

Chapter Eighteen

FATTENING DIETS

Oversupply of food does not necessarily produce excessive nutrition. The appropriation depends in part on the character of the food and the ease or difficulty with which it is converted into a condition suitable for absorption, in part on such extrinsic and intrinsic influences as heredity, age, sexual and psychical habits, exercise and sleep; but to a great extent also on personal peculiarities of the metabolic processes….

JAMES FRENCH, The Practice of Medicine, 1907

IN 1857, JOHN HANNNING SPEKE AND Richard Burton set off through West Africa to search for the source of the Nile River. After Burton fell ill, Speke discovered the river’s origin on his own. When he returned to the region five years later, according to his memoirs, he heard about the custom of local Abyssinian nobility to fatten up their wives to “such an extent that they could not stand upright.” He went to see for himself. “There was no mistake about it,” he recalled. “On entering the hut I found the old man and his chief wife sitting side by side on a bench…. I was struck with the extraordinary dimensions, yet pleasing beauty, of the immoderately fat fair one his wife. She could not rise; and so large were her arms that, between the joints, the flesh hung down like large, loose stuffed puddings.” Two weeks later, when Speke visited “another one of those wonders of obesity,” he took the opportunity to measure her. Her chest was fifty-two inches around. Her arms were nearly two feet in circumference and her thighs over two and a half feet.