The food-tracking necklace that listens to you chew

For those of you who would rather hear fingernails scrape a blackboard than listen to somebody chewing, this could be the stuff of nightmares.

A device is being developed that will translate the sounds of biting, grinding and swallowing into health information that can track your food intake and, ultimately, give you advice on how to improve your diet.

Computer scientist Wenyao Xu from the University at Buffalo (UB) is creating a library that catalogues the unique sounds that foods make as we consume them.

The library is part of a software package that supports AutoDietary, a high-tech, food-tracking necklace being developed by Xu and researchers in China.

Described in a study published by IEEE Sensors Journal, AutoDietary is like a Fitbit for our diet. Instead of tracking kilojoules burned by activity, it monitors kilojoule intake at the source — the human neck.

“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 Xu, PhD, assistant professor of computer science in UB’s School of Engineering and Applied Sciences.

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 food is swallowed. That data is sent to a smartphone via Bluetooth, where food types are recognised.

During the study, 12 test subjects aged 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% of the time.

“Each food, as it’s chewed, has its own voice,” said Xu, who said the 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 future studies to build on his library by testing different foods and recording the sounds they make. He also plans to refine the algorithms used to differentiate the foods to improve AutoDietary’s ability to recognise what’s being eaten.

The device still has limitations: it cannot differentiate between similar foods such as frosted corn flakes and regular corn flakes, nor can it distinguish the ingredients of complex foods such as soup.

To address these limitations, Xu is planning a biomonitoring device that would complement AutoDietary. The biomonitor would be activated once the necklace recognises that the user is eating a general category of food and 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.

Xu said the beauty of the system is that the user isn’t overwhelmed by a continuous stream of information as the device is only active as food is consumed and immediately after.