Chew on this: study finds additional chewing reduces food intake in young adults

(Medical Xpress) -- A new Iowa State University study confirms your mom was right, you should chew your food thoroughly. Mom's logic was that proper chewing would ease digestion, but the ISU research found that chewing food thoroughly -- 40 times before swallowing -- also reduces food intake in healthy young adults.

James Hollis, an Iowa State assistant professor of food science and (FSHN); and Yong Zhu, an FSHN doctoral research assistant, will present results from their research on Saturday, April 21, at the 2012 Conference in San Diego, Calif.

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 to study 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," said Hollis, who is also a researcher in Iowa State's Nutrition and Wellness Research Center. "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."

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 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," Hollis said. "That means you're getting more glucose and carbohydrates into the blood stream, which requires a larger insulin response to maintain ."

The researchers also learned that participants didn't like chewing food more than they had to. Hollis says that may have also been a contribution to appetite suppression.

"They [subjects] found it quite uncomfortable and not a pleasant sensation to be chewing foods after you've gotten that signal to swallow," he said. "So it may be that mastication only indirectly affects appetite. It might be the change in the characteristics of the swallowed food that may be having an impact too."

Hollis says that there are future plans to isolate mastication and determine its exclusive effect on appetite.

add to favorites email to friend print save as pdf

Related Stories

Munch-o-matic: Scientists develop the artificial mouth

May 05, 2008

For years scientists have tried to build an electronic tongue, a robotic tasting device that could have profound applications in improving food quality and safety. But before machines learn to taste their ...

Exercise reduces hunger in lean women but not obese women

Jun 17, 2008

Exercise does not suppress appetite in obese women, as it does in lean women, according to a new study. The results were presented Tuesday, June 17, at The Endocrine Society's 90th Annual Meeting in San Francisco.

Recommended for you

Law requiring release of health information upheld

1 hour ago

(HealthDay)—A state law that requires plaintiffs to release relevant protected health information before proceeding with allegations of medical liability has been upheld by a federal appeals court, according ...

Research highlights extent and effects of school violence

2 hours ago

Six percent of U.S. children and youth missed a day of school over the course of a year because they were the victim of violence or abuse at school. This was a major finding of a study on school safety by University of New ...

Planning for the move from children's to adult palliative care

5 hours ago

The differences between children's and adult palliative care services are too wide for young people with life-limiting conditions to negotiate, according to research by Bangor University. Commenting on the findings, the researchers ...

User comments