Anyone who has watched a cooking competition show knows how important it is to plate your food in a pretty and appetizing way.
That’s because people don’t eat just because they’re hungry, Michigan State University neuroscientist Alex Johnson wrote for the Conversation.
“The science behind eating behavior,” he wrote, “reveals that the process of deciding what, when and how much to eat is far more complex than just consuming calories when your body needs fuel. Hunger cues are only part of why people choose to eat.”
Eyes
There’s an old saying that goes: You eat with your eyes first.
Studies have show the way food looks can alter your perception of how it tastes.
“Color may be the most obvious visual cue, but expectations through learned associations are set by other visual cues as well, including gloss, evenness, and shape,” a 2012 study found. “These expectations exert cognitive top-down influences that can and sometimes do alter assessments of taste and flavor.”
Johnson said visual clues can influence feeding behavior. “For example, wrapping food in McDonald’s packaging is sufficient to enhance taste preferences across a range of foods — from chicken nuggets to carrots — in young children,” he wrote.
Gut
Interoceptive cues play an important role in influencing your decisions about food.
Interoception is the body’s ability to recognize and interpret its own internal cues, such as hunger, thirst, exhaustion and pain.
To explore these cues, researchers trained rats to expect food when they’re hungry, and not want it when full. The trained rats would generally avoid the feeding area when they weren’t hungry, because they had no expectation of food, the scientists found.
But when the rats received an injection of the hormone ghrelin, which can trigger hunger, they visited the feeding area more often, the researchers found.
Brain
The biochemical connection between your brain and your gut involves the vagus nerve, which helps to control the digestive tract.
According to Johnson, the nerve communicates nutrient information to the brain. Activating the nerve, he wrote, “can induce a pleasurable state.”
Mice have been trained to perform certain behaviors that will stimulate their vagus nerve, and they have learned to prefer foods and places where stimulation occurs.
Interoceptive awareness
Being aware of these interoceptive cues helps people make better decisions about when and where to eat.
Poor awareness, Johnson wrote, can lead to eating disorders such as anorexia. “(A)norexia may result when interoceptive signals, such as feelings of hunger, are unable to trigger the motivation to eat,” he said.
In addition, being unable to experience the “rewarding and pleasurable consequences” of food can lead to binge eating or overindulging.
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