Swiss Researchers Unveil Handheld Breathalyzer to Measure Fat Burning

Scientists at ETH Zurich have created a portable breath acetone analyzer, marketed as the Nutrion device, that detects the amount of acetone in exhaled breath to determine when the body is burning fat (ketosis). In a study published in the journal Device, twelve healthy adults aged 20‑37 provided 312 breath samples under varied conditions – light and intense exercise, high‑carb meals, ketogenic meals and fasting. The handheld detector measured acetone concentrations from 0.2 to 45 ppm in about 90 seconds and showed a correlation of 0.995 with laboratory mass‑spectrometry results, with average deviations of 0.15 ppm at 2 ppm and 0.42 ppm at 10 ppm. The device includes a moisture‑filter and operates reliably even in high humidity, remaining stable over eight months of continuous use. Researchers say the technology could enable personalized monitoring for obesity, diabetes, epilepsy and other metabolic disorders, as well as supporting athletes and diet programs. "If we want to make that information available to patients, we need to shrink those technologies into compact, user‑friendly devices," said study senior author Andreas Güntner.