Smartphone Breathalyzer Sniffs Out Fat-Burning Exercise

Huffing and puffing during exercise could feel less torturous if you got instant feedback showing that you were burning calories. A Japanese wireless carrier aims to deliver that health-monitoring satisfaction with a portable breathalyzer that, when connected to a smartphone, can sniff out the evidence of fat-burning when you exhale.

The breathalyzer, developed by Japanese telecom NTT Docomo, works by detecting acetone gas on people's breaths, according to Technology Review. That acetone is an end product of the chemical process that breaks down fatty acids in the human body—a sign that you're burning fat. Having the ability to monitor fat-burning could encourage many people in their efforts to shed pounds and stave off obesity or diabetes.

Docomo has been developing the palm-size breathalyzer over several years, but its most recent tests, looking at the tool's effect on the behavior of 17 overweight adults, were detailed in a new study published in the July issue of the Journal of Breath Research.

The study found that the concentration of acetone was raised only in the air exhaled by volunteers who did both light exercise and dieting, as opposed to those who only did light exercise or did nothing. This increased concentration corresponded with the loss of body fat over the two-week study (body weight and fat were measured to verify the results).

Such a device could also help diabetics monitor their condition, according to Tsuguyoshi Toyooka, a researcher at NTT Docomo. Toyooka told Technology Review that people with diabetes can have much higher acetone concentrations on their breath—the result of their bodies burning fat because of their inability to take up glucose from the blood.

But Docomo first had to figure out how to make a breathalyzer sensitive enough to detect acetone while ignoring interference from the ethanol and hydrogen also present in human breath. The solution came in the form of two semiconductor-based gas sensors—one with sensitivity to acetone and one sensitive to both acetone and ethanol—that effectively screen out the ethanol and hydrogen readings

The latest prototype of the breathalyzer can connect to smartphones through a cable or via Bluetooth. It indicates in about 10 seconds whether your efforts in the gym and at the dinner table are paying off. If Docomo's device eventually ends up on the market, it would join a growing host of health-monitoring devices aiming to make tracking your health as easy as checking your e-mail.