Still looking for the secret to effortless weight loss? It may be as simple as chewing gum while walking, Japanese researchers suggested on Saturday.
In experiments, they said, the heart rate of 46 people, aged 21 to 69, increased when they were given gum to chew while walking at a natural pace.
And while masticating caused a measurable physical difference in participants of both genders and across all age groups, it was most pronounced in men over 40, the team reported at the European Congress on Obesity in Vienna.
"Combining exercise and gum chewing may be an effective way to manage weight," the researchers said -- particularly in countries such as Japan where walking is the "most widely performed movement".
Previous research had found that gum chewing boosts heart rate and energy expenditure in people at rest.
This was the first study dedicated to studying its effects in people while walking, its authors said.
Volunteers completed two walking trials, each 15 minutes long.
In one they chewed two pellets of gum that contained three kilocalories. In the other, for comparison, they walked after ingesting a powder containing the same ingredients as the gum.
The team then measured participants' resting heart rate and walking heart rate in both legs, as well as the distance they covered at a natural pace, walking speed, and the number of steps taken.
In all participants, the mean heart rate was "significantly higher" in the gum trial, said the researchers.
In men over 40, it also boosted the distance walked, number of steps taken, and energy expended.
Though the study was not designed to explain the link, the team speculated it may have something to do with "cardio-locomotor synchronisation", a natural phenomenon whereby the heart beats in rhythm with a repetitive movement.
Obesity has become a global scourge. It increases a person's risk of developing heart disease and stroke, diabetes, and certain cancers.
"Effective preventive methods and treatments for obesity are needed," the researchers said.
The study was published in The Journal of Physical Therapy Science.