Hand-held gadget measures fat burning via breath

Researchers at ETH Zurich have developed a portable device capable of detecting when the body initiates fat burning during dieting or exercise. This device measures the acetone content in exhaled breath, a by-product of fat metabolism, with nearly the same accuracy as a high-precision mass spectrometer. The gadget functions similarly to police breathalyzers, operating effectively with non-experts and a smartphone application.

Users can monitor their fat metabolism at home, bypassing the need for professional support or blood tests. This innovation may facilitate tailored diets, treatments for metabolic disorders, and ketogenic therapies, such as those used for epilepsy management. Andreas Güntner, a professor at ETH Zurich’s mechanical and process engineering department, emphasizes that diets are individualized and self-monitoring can help people understand how their metabolism responds.

Güntner's research group, in collaboration with Alivion, an ETH spin-off, tested the device's reliability using 12 adults in a validation study, comparing its readings with blood tests and a mass spectrometer. The hand-held device, based on sensor technology developed over a decade at ETH Zurich, displays exceptional sensitivity, capable of detecting a single acetone molecule among 100 million others.

To ensure accurate results, the device filters out interference and guides users through exhalation via a smartphone app. The study's success marks a significant milestone for the researchers, showcasing the device's ability to detect subtle differences in fat metabolism with high accuracy and reliability. Future research aims to determine whether the hand-held device can personalize therapies for metabolic disorders and monitor ketogenic diets, particularly in children with epilepsy.

The ETH spin-off, Alivion AG, plans to expand the device's applications in medical diets, GLP-1 therapies, and amateur sports, seeking industry partners and investors for further scaling and development. The research findings are published in the journal Device, supported by Innosuisse, the Vontobel Foundation, and the Accentus Foundation.