A new handheld breath-testing device that detects when the body starts burning fat has been developed by researchers in Switzerland, with potential applications for managing conditions such as obesity, diabetes, and epilepsy. The device measures acetone, a molecule released into the breath as the body shifts its metabolism from carbohydrates to fat.

Scientists have long recognised breath acetone as an indicator of metabolic state, but traditional measurement methods have required bulky laboratory equipment or consumer devices that only function reliably at high acetone concentrations. The new device, designed by a team at ETH Zurich, aims to provide a compact and user-friendly alternative suitable for everyday use by patients.

In a study involving 12 healthy adults, the device measured acetone levels ranging from 0.2 to 45 parts per million across 312 breath samples. These readings were closely aligned with those obtained via mass spectrometry, the laboratory gold standard for analysing breath acetone. The results, published in the journal Device, suggest the device’s accuracy extends to detecting subtle variations in fat metabolism, which could be valuable in clinical studies and personalized treatment plans.

Professor Andreas Guntner, senior author of the study, emphasised the importance of creating smaller, accessible technology: “If we want to make that information available to patients, we need to shrink those technologies into compact, user-friendly devices.” Simone Hersberger, also from ETH Zurich, noted that the device’s high performance meets the precision required for detecting slight metabolic changes crucial to managing various metabolic disorders.

The device, which produces results within approximately 90 seconds, has been commercialised under the name Nutrion by ETH spin-off company Alvion AG. Its developers believe this breathalyser could provide a practical tool helping individuals and healthcare providers track metabolism in real time and tailor treatments accordingly.

While the device shows promise, real-world application and long-term clinical validation will be important to determine its broader effectiveness in disease management and metabolic monitoring. Nonetheless, the introduction of a portable acetone breath tester represents a significant step toward non-invasive, accessible metabolic assessment.