Living large.

New Yorker valiantly tries to explain – scientifically – why it is that Americans (and the rest of the Western World) are getting so darned fat:

The elasticity of the human appetite is the subject of Brian Wansink’s “Mindless Eating” (2006). Wansink is the director of Cornell University’s Food and Brand Lab, and he has performed all sorts of experiments to test how much people will eat under varying circumstances. These have convinced him that people are—to put it politely—rather dim. They have no idea how much they want to eat or, once they have eaten, how much they’ve consumed. Instead, they rely on external cues, like portion size, to tell them when to stop. The result is that as French-fry bags get bigger, so, too, do French-fry eaters.

Consider the movie-matinée experiment. Some years ago, Wansink and his graduate students handed out buckets of popcorn to Saturday-afternoon filmgoers in Chicago. The popcorn had been prepared almost a week earlier, and then allowed to become hopelessly, squeakily stale. Some patrons got medium-sized buckets of stale popcorn and some got large ones. (A few, forgetting that the snack had been free, demanded their money back.) After the film, Wansink weighed the remaining kernels. He found that people who’d been given bigger buckets had eaten, on average, fifty-three per cent more.

Before McDonald’s discovered the power of re-portioning, it offered just a small bag of French fries, which contained two hundred calories. Today, a small order of fries has two hundred and thirty calories, and a large order five hundred. (Add fifteen calories for each package of ketchup.) Similarly, a McDonald’s soda used to be eight ounces. Today, a small soda is sixteen ounces (a hundred and fifty calories), and a large soda is thirty-two ounces (three hundred calories). Perhaps owing to the influence of fast-food culture, up-sizing has by now spread to all sorts of other venues. In a 2002 study, Marion Nestle, a nutrition professor at New York University, and Lisa Young, an adjunct there, examined the offerings, past and present, at American supermarkets. They found that during the nineteen-eighties the amount of food that was counted as a single serving increased rapidly. A similar jump showed up in cookbooks; when the researchers compared dessert recipes in old and new editions of volumes like “The Joy of Cooking,” they discovered that, even in cases where the recipes themselves had remained unchanged, the predicted number of servings had shrunk.

Our eyes — our eyes really are getting bigger than our stomachs.