Mom Was Right: Chewing Food Longer Increases Satiety

AMES, IowaNew research conducted at Iowa State University validates moms age-old advice to chew your food slowlychewing may play a more complex role in the digestion process, impacting nutrient absorption, and feelings of satiety or fullness.

The researchers studied 20 Iowa State students who were given a metronome and told to chew every time it ticked, with half chewing 15 times and the other half 40 times. Researchers monitored the subjects' appetite and took blood samples to study plasma glucose levels and hormones. Those who chewed more ate less.

"When people chewed the pizza 40 times before swallowing, there was a reduction in hunger, preoccupation with food and a desire to eat," they said. "There was an increase in CCK, which is a hormone related to fullness and satiety. And there was a reduction in ghrelin, another hormone that stimulates the brain to increase appetite."

The researchers also found plasma glucose and insulin levels were higher among the subjects who chewed the pizza 40 times.

"And the reason, I think, is that the increased mastication breaks down the food more thoroughly in the mouth, and this really facilitates nutrient absorption," they said. "That means you're getting more glucose and carbohydrates into the blood stream, which requires a larger insulin response to maintain plasma glucose levels."