New food-tracking necklace 'listens' to what you eat

Scientists have developed a high-tech necklace that can track your calorie intake by 'listening' to sounds of different foods as you chew them.
Researchers are creating a library that catalogues the unique sounds that foods make as we bite, grind and swallow them.
The library is part of a software package that supports AutoDietary, a food-tracking necklace being developed by researchers from the University at Buffalo (UB) in US and Northeastern University in China.
Unlike other wearable devices that track burned calories, AutoDietary monitors caloric intake at the neck, researchers said.
"There is no shortage of wearable devices that tell us how many calories we burn, but creating a device that reliably measures caloric intake isn't so easy," said Wenyao Xu, assistant professor at UB.

AutoDietary wraps around the back of the neck like a choker necklace. A tiny high-fidelity microphone - about the size of a zipper pull - records the sounds made during mastication and as the food is swallowed.

That data is sent to a smartphone via Bluetooth, where food types are recognised.
The study describes how 12 test subjects, male and female, ages 13 to 49, were given water and six types of food - apples, carrots, potato chips, cookies, peanuts and walnuts.
AutoDietary was able to accurately identify the correct food and drink 85 per cent of the time, researchers said.

"Each food, as it's chewed, has its own voice," said Xu, adding that device could someday help people suffering from diabetes, obesity, bowel disorders and other ailments by enabling them to better monitor their food intake and, thus, improve how they manage their conditions.
Xu plans to refine the algorithms used to differentiate the foods to improve AutoDietary's ability to recognise what is being eaten.
While promising, a wearable necklace that measures sound has limitations when used alone. For example, it cannot differentiate similar foods such as frosted corn flakes and regular corn flakes. It also can not distinguish the ingredients of complex foods such as soup or chili.

To address these limitations, Xu is planning a biomonitoring device which would complement AutoDietary.
The biomonitor would then determine the nutritional value of the food via blood sugar levels and other measurements.
The system then gathers and presents this information on a smartphone, while providing suggestions on healthier eating.
The study was published in the IEEE Sensors Journal.