Why we eat so much
(WASHINGTON POST) There seems to be a big misunderstanding.
Almost 20 years ago, psychology professor and biologist Paul Rozin tested a theory about food. Many people believed their bodies were good at telling them when to start and stop eating, but he wasn’t so sure.
“A lot of things that control what and how much people eat have nothing to do with the state of nutrition,” Rozin told The New York Times in 1998.
His experiment, published in the journal Psychological Science, was simple, but ingenious. He worked with two severely amnesic patients, whose memory had been damaged by illness and who had difficulty recalling things that happened more than a minute before, and fed them a meal. At least 1o minutes later, he fed them another. And at least 10 minutes after that, he fed them a third. He repeated the experiment on three separate occasions, and each time the same thing happened: they eagerly ate the food that was served to them. One of the participants even announced, after having a third lunch, that he planned to “go for a walk and get a good meal.”
“Without their memory, what they had eaten previously had absolutely no impact on how much they ate a second and even third time,” said David Just, a professor of behavioral economics at Cornell who studies consumer food choices. “It was fascinating; this widely help assumption didn’t really hold up.”