The new hand‑held device that measures fat burning via breath could give users a simple way to track metabolic changes without laboratory tests.
How the sensor works
The instrument detects acetone in exhaled air, a by‑product released when the body switches from burning carbohydrates to burning fat. Its sensor technology, developed at ETH Zurich for more than a decade, can identify a single acetone molecule among a hundred million other molecules. The team paired the sensor with a smartphone app that guides the user through a controlled exhalation, ensuring the sample comes from deep in the lungs.
Lead author Simone Hersberger explained that the device measures the volume of air exhaled and only captures a portion after a set time. “Otherwise, every reading would be slightly different,” she said. The system also includes a filter that blocks interfering gases, a shortcoming of earlier acetone breathalyzers that often responded to food or drink residues.
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Validation study results
In a study of 12 adults, the researchers recorded 312 breath readings with the hand‑held unit and compared them to blood tests and a high‑precision mass spectrometer, the analytical gold standard. Tests spanned light and intensive exercise as well as various diet regimes. The data showed the portable device’s readings were practically identical to the laboratory instrument, and the performance remained consistent over several months.
Reporters noted that the device’s accuracy matches that of professional equipment, yet it can be operated by non‑experts. This reliability opens the possibility of monitoring diets, metabolic disorders such as diabetes, and ketogenic therapies used for epilepsy without frequent blood draws.
Professor Andreas Güntner of ETH Zurich added, “When it comes to diets, there’s no rule of thumb that works for everybody. Ideally, people should self‑monitor to see how their own metabolism responds.” He emphasized that independent methods comparable to blood‑glucose monitoring are needed for broader metabolic tracking.
While the study sample is modest, the findings suggest the device could fill a gap in personalized health monitoring. If larger trials confirm these results, clinicians might rely on breath analysis to adjust treatment plans in real time, potentially reducing the need for invasive testing.
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Potential applications and next steps
Researchers are now collaborating with the University Children’s Hospital Zurich to examine whether the device can help children on ketogenic diets for epilepsy monitor their metabolic state more precisely. Other proposed uses include tracking medical diets, optimizing GLP‑1 therapies that promote weight loss, and providing feedback for amateur athletes seeking to fine‑tune training regimens.
From a practical standpoint, the ability to obtain near‑lab quality data with a pocket‑sized gadget could reduce the burden on healthcare systems, especially in monitoring chronic conditions where frequent testing is required.
Future research will need to address long‑term durability, user adherence, and the influence of variables such as hydration or ambient temperature on breath readings. Demonstrating consistent performance across diverse populations will be essential before the technology can be recommended for routine clinical use.