Economix: Your Plate Is Bigger Than Your Stomach

Late last year, a little book called Mindless Eating started appearing in bookstores. It was written by Brian Wansink, a Cornell professor who has spent his career doing brilliantly mischievous experiments about the psychology of eating.

Brian Wansink has tempted research subjects with giant tubs of popcorn and bottomless bowls of soup.

In one of my favorites, Mr. Wansink gave away five-day-old popcorn — stale enough to squeak when it was eaten, he wrote — to moviegoers one day at a theater in the Chicago suburbs. The crux of the experiment lay in the size of the buckets that held the popcorn. Some people got merely big buckets, while others received truly enormous ones. Both sizes held more popcorn than a typical person could finish.

Yet when the Wansink research team weighed the buckets after the movie, there was a huge difference in the amounts the two groups ate. Those with the bigger buckets inhaled 53 percent more on average, suggesting that a lot of stale popcorn is somehow more appealing than a little stale popcorn.

Over the years, Mr. Wansink has done similar experiments with everything from different-size dinner plates to bottomless bowls of tomato soup that are secretly connected to a tube underneath a restaurant table. His overarching conclusion is that our decisions about eating often have little to do with how hungry we are. Instead, we rely on cues like the size of a popcorn bucket — or the way we organize our refrigerator — to tell us how much to eat. These cues can add 200 calories a day to our diet, but the only way well notice we are overeating is that our pants will eventually get too tight.

The scariest part is that most of us think we are immune to these hidden persuaders. When the moviegoers were told about the popcorn experiment afterwards, most of them scoffed at the idea that their bucket size had any effect on them. Things like that dont trick me, said one of the gorgers.

After reading the first few chapters of Mindless Eating, I called Mr. Wansink, an energetic 46-year-old Iowan, to talk about his research. As luck would have it, he said that he was coming down to New York a few days later to give a speech. In a flash of masochism, I then asked if he would be willing to stop by my apartment and tell me everything that was wrong with my kitchen.

Thatd be so cool! he replied.

•

Toward the end of Mindless Eating, there is a short passage making it clear that Mr. Wansinks work is about far more than just food. The 19th century has been called the Century of Hygiene, he writes. The 20th century was the Century of Medicine.

This century, he continues, will be the Century of Behavior Change. Medicine is still making fundamental discoveries that can fight disease, but changing everyday, long-term behavior is the key to adding years and quality to our lives. This will involve reducing risky behavior and making changes in exercise and nutrition. There isnt a simple prescription that can be written for such behavior change.

Over the last couple of decades, a new field of economics, behavioral economics, has emerged to explain why people so often act in ways that are contrary to their own interests. They overeat, smoke, forget to take their medicine and dont save enough for retirement, saying all the while that they wish they could change. Figuring out how to turn these wishes into action could put a dent in some big social problems.

Last year, President Bush signed a new pension law that was based in part on this idea. It gave companies an incentive to sign up workers automatically for 401(k) plans. The workers can still opt out; in fact, they have the same range of choices they have always had. But if they do nothing, a small part of their salary is set aside for retirement.

The pension bill sprang directly from academic research showing that automatic plans vastly increased the amount of money that people saved. Its the success of behavioral economics, by far, Daniel Kahneman, the Nobel Prize-winning psychologist who helped found the field, recently told me.

Whether its 401(k)s or food, the way choices are presented to people — what the economist Richard Thaler calls choice architecture — has a huge effect on the decisions they make. As Mr. Wansink and I stood in front of my pantry, he was making the exact same point.

He started off with some praise, which I was perfectly willing to accept. What all this cues up is food preparation, he said, pointing to bottles of olive oil and vinegar, sacks of rice and various baking ingredients. The default when you open a pantry like this isnt convenience — its what are we going to make tonight?

E-mail: Leonhardt@nytimes.com

Tag Cloud

External Information

Additional Information

Where Am I?