Recent findings have shown that our appetite and food intake are influenced by a large number of factors besides our biological need for energy, including our eating environment and our perception (感知) of the food in front of us. A new study suggested that our short-term memory may also play a role in appetite. Several hours after a meal, people's hunger levels were predicted not by how much they'd eaten but rather by how much food they'd seen in front of them — in other words, how much they remembered eating.
This difference suggests the memory of our previous meal may have a bigger influence on our appetite than the actual size of the meal, says Jeffrey M. Brunstrom, a professor of experimental psychology at the University of Bristol.
"Hunger isn't controlled merely by the physical characteristics of a recent meal. We have identified an independent role for memory for that meal, " Brunstrom says. "This shows that the relationship between hunger and food intake is more complex than we thought. "
These findings echo earlier research that suggests our perceptions of food can sometimes trick our body's response to the food itself. In a 2016 study, for instance, people who drank the same 380-calorie milkshake on two separate occasions produced different levels of hunger-related hormones (荷尔蒙), depending on whether the shake's label said it contained 620 or 140 calories. Moreover, the participants reported feeling more full when they thought they'd consumed a higher-calorie shake.
