A handheld breath analyser developed at ETH Zurich can tell how fast the body is burning fat by measuring acetone in exhaled air. The device, created in the molecular sensing group of Andreas Güntner with doctoral student Simone Hersberger as lead author, resembles a police breathalyser and pairs with a smartphone app. The underlying sensor technology has been refined at ETH for over a decade, and the validation study appears in the Cell Press journal Device.
Acetone is a by-product of fat metabolism, and its concentration in breath rises when the body switches from burning carbohydrates to burning fat. The sensors can pick out one acetone molecule among 100 million others, while a filter blocks interfering compounds from food and drink and the app ensures each sample comes from deep in the lungs. In a validation study with University Hospital Zurich, 312 readings from 12 adults matched blood tests and a high-precision mass spectrometer almost exactly.
Reliable at-home measurement of fat metabolism could support personalised nutrition, monitoring of ketogenic diets, and tracking responses to treatments for metabolic conditions, all without needles. The ETH spin-off Alivion is commercialising the technology as Nutrion and seeking partners to scale production, while a study with the University Children's Hospital Zurich is already examining its use for children on ketogenic diets for epilepsy.