Memory is just one of the subtle but powerful factors that affect eating habits. Photo / iStockAlmost 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 >>>