By Tia Ghose, LiveScience
Contrary to popular diet advice, chewing gum may not help people eat less or lose weight, new research suggests.
In fact, the study, published in the April issue of the journal Eating Behaviors, suggests that chewing gum may lead people to eat chips, cookies and candy instead of fruits and veggies. That's because menthol, the chemical responsible for the minty-fresh flavor of some types of gum makes fruits and veggies taste funny.
The chemical change is the same reason why "when you brush your teeth and then drink orange juice, it tastes bad," said study co-author Christine Swoboda, a doctoral candidate in nutrition at Ohio State University.
And because it may evoke thoughts of food and get digestive juices flowing, some people hypothesized that chewing gum could make people hungrier. But scientists have also hypothesized the opposite — that the act of chewing could make people feel more full and, in turn, eat less. To test that claim, the gum manufacturer Wrigley even offers grants for scientific research on the subject. [ The 7 Biggest Diet Myths Debunked ]
But despite claims to the contrary, only a few studies have looked at whether chewing gum aids weight loss, and these have found conflicting results, Swoboda said.
"We were interested in seeing 'Does this really help with weight loss?'" Swoboda told LiveScience.
To find out, Swoboda and colleague Jennifer Temple of the University at Buffalo asked 44 volunteers to play a slotmachine-style game in exchange for food. Some of the participants played for mandarin oranges or grapes, while others played for potato chips or M&Ms.
Prior to playing the game, half of the participants chewed either Juicy Fruit gum or Wrigley's Spearmint gum.
Those who chewed the minty gum were significantly less likely to play as long for the fruit, suggesting they were less motivated to get them when chewing gum. The fruity gum showed a smaller effect that wasn't statistically significant.
In a second experiment, the researchers asked participants to keep a food journal recording what they ate. Some of the time, the participants were asked to chew a mint green-tea gum before every meal and snack for a week, while other times, they simply had to record their food intake.
When chewing gum, participants ate fewer meals. But that didn't translate into fewer calories: Instead, people were actually getting fewer nutrients in their diet and about the same amount of calories.
It could be that the menthol in mint, which interacts with nutrients in fruits and veggies to create a bitter flavor, was turning people off to the healthy foods, Swoboda said.
People "ate less fruits and vegetables, because in their head, they thought 'I have to chew gum before every meal — do I really want a snack of grapefruit?'" she said. "Whereas, they were like, 'I'm so hungry I'm going to eat this double cheeseburger and it will taste the same.'"
The findings are interesting, but they don't reveal how gum might change people's eating habits in the long run, said Brett Carter, a food behavior researcher at the University of Washington in Seattle, who was not involved in the study.
In addition, using food diaries is a notoriously inaccurate measure of calories, Carter added.
"As you can imagine people aren't very good at keeping track of exactly how they eat," Carter told LiveScience. "Translating it to calories can lend itself to a lot of error."
More from LiveScience: