Newest weight loss gadget? Meet the "Bite Counter"

bite counter, calorie count
A woman wears a Bite Counter Clemson University

(CBS) Call it a pedometer for the mouth? The latest health gadget to help people stay fit can track how much they're eating - for about 800 bucks.

Meet the Bite Counter.

Like a pedometer, the device tracks motion, so every time a person lifts a hand or a fork, it counts a bite. The researchers behind it then use a formula to count calorie intake similar to how exercise equipment estimates how many calories an activity burns. This data can be used to monitor how many calories people are eating long-term. People can also set a bite limit so if they snack too much an alarm will go off.

One obvious question comes to mind - can't people just watch what they eat themselves?

According to one of its creators, people may not be best indicators.

"Studies have shown that people tend to underestimate what they eat by large margins, mostly because traditional methods rely upon self-observation and reporting," co-creator Dr. Eric Muth, professor of psychology at Clemson University, said in a written statement.

How can calorie counts be accurate if a person eats a cheese burger for one meal and an apple the next?

"Obviously a bite of an apple is not the same calories as the bite of a candy bar," Dr. Muth told CBS News in a voice-mail. "But the device is intended for long term use." If you average bites across meals and days, he said, a pattern emerges of an average calorie count. Also people tend to eat the same foods week after week which stabilize the calorie counts over time. Dr. Muth told CBS News he averages about 20 calories per bite, while his colleage averages 25.

The counter isn't perfect. The creators said it tested 90 percent accurate in studies, but it sometimes picks up non-eating motions like using a napkin or arm gestures. But the creators say that shouldn't affect long-term bite tracking since people tend to conduct these gestures meal after meal.

But one expert, Dr. Marion Nestle, professor of nutrition, food studies, and public health at New York University, told CBS News in an email there's already a piece of technology that can help people count calories - it's called a scale.

"It's really difficult to estimate calorie intake and expenditure with any reasonable degree of accuracy," she said. "A much better way, demonstrated in several research studies, is regular monitoring of weight using a common household scale." Nestle said weight tends to fluctuate by a pound or two every day, so once the trend goes up, it's time to eat less.

In this day and age, where over one-third of the country is obese, anything that gets people to monitor their meals can't hurt.