Next time you eat, take off your headphones, switch off the TV and pay attention to the noise your food makes while you chew, as the sounds help control how much you consume, scientists say.
The "Crunch Effect," as researchers call it, suggests you are likely to eat less if you are more conscious of the sound your food makes while eating.
Therefore, watching loud TV or listening to loud music while eating can mask eating sounds that keep you in check, researchers said.
"For the most part, consumers and researchers have overlooked food sound as an important sensory cue in the eating experience," said study coauthor Gina Mohr, an assistant professor at Colorado State University in US.
"Sound is typically labelled as the forgotten food sense," said Ryan Elder, assistant professor at the Brigham Young University in US.
"But if people are more focused on the sound the food makes, it could reduce consumption," Elder said.
The effect comes from the sound of mastication: chewing, chomping, crunching.
Elder and Mohr carried out three separate experiments on the effect of that "food sound salience" and found even suggesting people think of eating sounds through an advertisement can decrease consumption.
The most fascinating experiment discovered people eat less when the sound of the food is more intense.
In that study, participants wore headphones playing either loud or quiet noise while they ate snacks. Researchers found the louder noise masked the sound of chewing and subjects in that group ate more - 4 pretzels compared to 2.75 pretzels for the "quiet" group.
"When you mask the sound of consumption, like when you watch TV while eating, you take away one of those senses and it may cause you to eat more than you would normally," Elder said.
"The effects many not seem huge - one less pretzel - but over the course of a week, month, or year, it could really add up," he said.
Researchers said the main takeaway for people should be the idea of mindfulness.
In other words, being more mindful of not just the taste and physical appearance of food, but also of the sound it makes can help in "nudge" consumers to eat less.
The research was published in the journal Food Quality and Preference.
