In today's excerpt--supersizing and the "thrifty gene":



"That distinction [of inventing supersizing] belongs to a man named David Wallerstein. Until his death in 1993, Wallerstein served on the board of directors at McDonald's, but in the fifties and sixties he worked for a chain of movie theaters in Texas, where he labored to expand sales of soda and popcorn--the high-markup items that theaters depend on for their profitability. As the story is told in John Love's official history of McDonald's, Wallerstein tried everything he could think of to goose up sales--two-for-one deals, matinee specials--but found he simply could not induce customers to buy more than one soda and one bag of popcorn. He thought he knew why: Going for seconds makes people feel piggish.



"Wallerstein discovered that people would spring for more popcorn and soda--a lot more--as long as it came in a single gigantic serving. Thus was born the two-quart bucket of popcorn, the sixty-four-ounce Big Gulp, and, in time, the Big Mac and the jumbo fries, though Ray Kroc himself took some convincing. In 1968, Wallerstein went to work for McDonald's, but try as he might, he couldn't convince Kroc, the company's founder, of supersizing's magic powers.



" 'If people want more fries,' Kroc told him, 'they can buy two bags.' Wallerstein patiently explained that McDonald's customers did want more but were reluctant to buy a second bag. 'They don't want to look like gluttons.'



"Kroc remained skeptical, so Wallerstein went looking for proof. He began staking out McDonald's outlets in and around Chicago, observing how people ate. He saw customers noisily draining their sodas, and digging infinitesimal bits of salt and burnt spud out of their little bags of French fries. After Wallerstein presented his findings, Kroc relented and approved supersized portions, and the dramatic spike in sales confirmed the marketer's hunch. Deep cultural taboos against gluttony--one of the seven deadly sins, after all--had been holding us back. Wallerstein's dubious achievement was to devise the dietary equivalent of a papal dispensation: Supersize it! He had discovered the secret to expanding the (supposedly) fixed human stomach.



"One might think that people would stop eating and drinking these gargantuan portions as soon as they felt full, but it turns out hunger doesn't work that way. Researchers have found that people (and animals) presented with large portions will eat up to 30 percent more than they would otherwise. Human appetite, it turns out, is surprisingly elastic, which makes excellent evolutionary sense: It behooved our hunter-gatherer ancestors to feast whenever the opportunity presented itself, allowing them to build up reserves of fat against future famine. Obesity researchers call this trait the 'thrifty gene.' And while the gene represents a useful adaptation in an environment of food scarcity and unpredictability, it's a disaster in an environment of fast-food abundance, when the opportunity to feast presents itself 24/7. Our bodies are storing reserves of fat against a famine that never comes."



Michael Pollan, The Omnivore's Dilemma, Penguin, Copyright 2006 by Michael Pollan, pp. 105-106.