Want help losing those unwanted holiday pounds?

Try chewing gum.

That's the advice offered by researchers at the Mayo Clinic in a letter published last week in the New England Journal of Medicine.

James Levine and Paulette Baukol of Mayo and Ioannis Pavlidis of Honeywell Technology Center in Minneapolis measured the energy expended by seven nonobese gum chewers in "a temperature-controlled, darkened, silent laboratory."

The participants wore masks that measured expired air but "allowed unopposed jaw movement" and they were tested while resting with their arms and legs supported. Each chewed 8.4 grams of calorie-free gum for 12 minutes at a normal speed calibrated with the aid of a metronome.

The gum was then removed and the researchers measured patients' energy expenditure for another 12 minutes.

Levine and his colleagues found that in all subjects, energy expenditure increased by about 11 calories an hour while they were chewing gum.

That's about the same number of calories--about 70--expended by standing for one hour, the researchers wrote, but less than the 106 calories expended by walking one mile an hour.

Here's the good news: "Gum chewing is sufficiently exothermic that if a person chewed gum during waking hours and changed no other component of energy balance, a yearly loss of more than 5 kg [11 lbs] of body fat might be anticipated. Chewing of calorie-free gum can be readily carried out throughout the day, and its potential effect on energy balance should not be discounted," they conclude.

This is not the first time that Mayo researchers have suggested that a nonexercise-related activity may help people stay thin.

Earlier this year a team of Mayo researchers, Levine among them, attracted worldwide publicity with the publication of a study that found that fidgeting keeps some people thin. One man in that study expended nearly 700 calories in one day by fidgeting--the equivalent of running six miles.

In the earlier study 16 subjects, 12 men and four women, were fed more than 1,000 calories per day over their normal food intake for two months. Exercise was forbidden and all meals were prepared in Mayo's kitchens.

At the end of the study, the weight gain varied from two to 16 pounds; women gained the most weight. On average, participants burned about 328 calories per day by fidgeting, although some burned much more because they fidgeted more, a mechanism that may have been triggered by overeating, researchers suggest.

Within a few months after people returned to their normal lives, they lost the weight gained during the study.