ZURICH: If you’re looking to lose weight, knowing when your body starts to burn fat during exercise - a process known as lipolysis - is important.
Instead of analysing blood or urine samples for biomarkers, lipolysis can now be measured by simply blowing into a tube, according to a report in Science Daily.
Scientists at ETH Zurich and the University Hospital Zurich have developed a small gas sensor that tests for the presence of acetone in a person's exhalations during exercise. This allows for the real-time monitoring of lipolysis. Acetone is one of the body’s by-products that finds its way into the person’s breath when fat is burned.
Dr Andreas Guntner told Science Daily that the sensor can detect a single acetone molecule in hundred million molecules. It also measures acetone exclusively, so the other known volatile components, which amount to more than 800 in a person’s breath, do not affect the measurement.
Together with pulmonary specialists at the University Hospital Zurich, Dr Guntner and his colleagues tested the sensor on volunteers after they had each completed a one-and-a-half-hour session on a bicycle ergometer with two short breaks. "We were able to show how the acetone concentration in the exhalations varies greatly from person to person," said Dr Guntner.
According to the Science Daily report, the sensor has a chip coated with a porous film of tungsten trioxide nanoparticles.
The chip was developed seven years ago when Professor Sotiris Pratsinis and his colleagues from ETH Zurich discovered that tungsten trioxide nanoparticles interacted with acetone if the nanoparticles’ atoms were arranged in a certain crystalline structure. This interaction reduces the electrical resistance of the chip which can be measured.
The report mentioned that the chip was originally meant to diagnose diabetes because the breath of patients with untreated Type 1 diabetes contains high concentrations of acetone. But since the sensor was found sensitive enough to detect the low acetone concentrations in a person's exhalations during exercise, the researchers changed tack.
Although the chip is already the size of a one-cent Euro coin in the study, according to Science Daily, the researchers are working on making it even smaller.
"This would allow athletes and people who want to lose weight to check for themselves when their bodies begin to burn fat so that they can optimise their training regimen," says Dr Guntner.