New Gadget Measures Acetone Expelled From Lungs When Fat Is Burned

Japanese scientists have developed a pocket-sized breathalyzer that measures -- not alcohol -- in the breath, but acetone, an indicator of fat metabolism. Acetone is expelled through the lungs when fat is broken down. The new device can detect acetone at concentration sin  the range of 0.2 to 50 parts-per-million. It weighs only 4.5 ounces and uses two AA batteries. It uses a pressure sensor to detect exhaled breath and two types of semiconductor-based sensors to detect acetone. The researchers believe their device will be useful in estimating fat loss from changes in breath acetone concentrations and determining whether diets are really working.