A small handheld device that can tell whether a person's body is burning fat may be on its way out of the laboratory and into everyday use. Researchers have developed a breathalyzer that detects acetone in exhaled air, a byproduct produced when the body burns fat for fuel, and found it performs as well as standard blood-based tests in real-world conditions.
According to a report by Engadget, the study was published in the scientific journal Device and supervised by researcher Andreas Güntner. The device was tested on 12 participants across a variety of diet and exercise situations.
When the body runs low on carbohydrates and begins breaking down fat for energy, it enters a state called ketosis. That process produces ketones in the blood and acetone in the breath. Both can be measured to confirm fat burning is occurring. Blood tests are the more established method, but breath tests have long been seen as more convenient, if less reliable outside of a controlled environment.
The challenge with acetone breath tests has always been accuracy. Humidity levels and breathing patterns can both distort readings. The researchers addressed this by engineering the breathalyzer to filter out excess moisture and contaminants. They also built a companion app that walks users through the breathing process in real time.
The app monitors how much pressure a person applies while exhaling and adjusts the timing of the sample collection to match conditions as close as possible to a blood test. It can tell when a user is breathing too hard or too softly and corrects for it on the spot.
The device used in the study has since been commercialized under the name Nutrion. It follows an earlier consumer product called Lumen, which attempted to track fat burning by measuring carbon dioxide in breath rather than acetone. The two devices operate on a similar concept but use different metabolic markers.
Researchers say the applications go beyond fitness tracking. Frequent, non-invasive metabolic measurements could be useful in clinical settings, including monitoring whether GLP-1 therapies are producing the expected metabolic effects in patients. Athletes looking to fine-tune their nutrition and energy use around training could also benefit from more accessible and accurate fat-burning data.
The study found that across its 12 participants and the various conditions tested, the breathalyzer's readings closely matched what traditional lab analysis would have shown. The researchers say this suggests the device and its app-based guidance system are capable of producing clinically meaningful data outside a laboratory setting.
