Chewing Gum May Keep Calories Off, Study Suggests

Don't spit out the gum just yet. The jury's still out, but it is possible that that chewy goodness could help you to lose weight.

University of Rhode Island associate professor of nutrition Kathleen Melanson is conducting research on the effects of gum chewing on appetite and metabolism.

The initial hypothesis of the study was that the act of chewing gum would suppress appetite and stimulate metabolism.

Early results from the study, which has been underway since September, support the hypothesis, Melanson said.

Subjects who eat less following a gum-chewing session, tend to express less hunger in the study's questionnaires and show a significant increase in metabolic rate, Melanson said. But she cautioned against reading too much into the preliminary findings.

"To take data that were collected from a study that was only for a half a day and try to extrapolate that to a weight loss regimen, it's kind of taking too much of a leap of faith," she said.

The inspiration for the gum study came from a series of slow eating studies that Melanson has been conducting since 2005.

In these studies, Melanson consistently found that eating slowly led to eating less.

Prior to this research, Melanson said, other researchers had showed mixed results, with some finding that slow eating had no effect and some that it lead to greater consumption.

On further investigation, Melanson found that the studies she had participated in were the only ones to emphasize thorough chewing as a means to slow eating.

"So I said maybe there's something to do with chewing here because our lab's the only one doing the chewing and our lab has shown the most consistent results," she said.

From there Melanson found studies on rodents showing that the action of chewing sent nerve impulses to the brain suppressing appetite and increasing fat-burning rates.

The challenge, Melanson said, was to study chewing in humans without introducing any calories, and the answer was sugar free gum.

"This way we're getting them to chew but not swallow any calories ... so that's kind of what led me to this whole hypothesis," Melanson said.

Unfortunately, the study has not yet shown the same fat-burning effect in humans as in rodents, but in other respects is showing promise as foundation for future research, Melanson said.

"It kind of substantiates our hypothesis that there is something going on with the chewing, that that's what's making our lab's approach to slow eating different from other approaches," she said.

Melanson and post-doctoral student Daniel Kresge are collecting data with the help of volunteer human test subjects.

Subjects participate in the study over the course of a morning, chewing gum for 20 minutes prior to a standardized breakfast, and in two identical sessions in the three hours before lunch.

During the period between breakfast and lunch, subjects' metabolic rates are tested with an indirect calorimeter, a device that gauges metabolism through respiration.

For their participation, subjects receive a $60 stipend.

Volunteers between the ages of 18 and 48 are still being accepted.

The Obesity Society, a scientific group dedicated to the study of obesity, is funding the research.

Melanson hopes to present the results of the study at the annual meeting of the Obesity Society in August. The study will be published in the group's monthly journal, Obesity.

This story was filed by UWIRE, which offers reporting from more than 800 colleges and universities worldwide. Read more at