Study finds additional chewing reduces food intake in young adults

Posted by AFN Staff Writers on 19th April 2012

A new study by researchers at Iowa State University, in the US, has found that chewing food thoroughly – 40 times before swallowing – reduces food intake in healthy young adults.

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.

Iowa State assistant professor of food science and human nutrition, James Hollis said, “When people chewed the pizza 40 times before swallowing, there was a reduction in hunger, preoccupation with food and a desire to eat.

“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,” Professor Hollis said.

Hollis had published an earlier paper on chewing nuts. That research also found that subjects who chewed more reduced their appetite, but they also increased the amount of lipids absorbed from the nuts.

“So while you get a reduced appetite, you also absorb more energy from the nuts,” he said. “It’s not clear which is more beneficial – the reduced appetite, or whether it’s outweighed by the increased absorption of lipids and fat.”

He found similar results in the new study, noting that plasma glucose and insulin levels were higher among the subjects who chewed the pizza 40 times.