Prior to the interest in high protein diets, tracking ketone levels has long been an important health indicator for specific diseases and health conditions. Ketones are a class of organic compound that occurs when the liver breaks down fatty acids to produce energy for muscles. For diabetics and people with specific forms of epilepsy, the presence and level of ketones can have great significance. Diabetics who go into a state of ketoacidosis from low glucose and high ketone levels can lapse into a coma that can be fatal unless they receive timely treatment.  On the other hand, ketogenic diets are sometimes used to control epilepsy in children and in adults with intractable forms of the condition.

Traditionally ketone levels are tested with urine dip strips or by blood tests. Blood tests are bothersome (and painful) and urine tests can deliver false positive or negatives in the presence of some medications and dehydration. Because the presence of ketones like acetone (the simplest form) can be detected on the breath, Michel Lundell, a Swedish engineer who had severe epileptic seizures in 2004 and in 2012, founded Ketonix developed a handheld ketone breath analyzer.

The Ketonix 2015 is a non-invasive, FDA Class 1 medical device registered for use in the detection ketone production and usage by measuring exhaled breath. A new version, the Ketonix 2017 is now available with a USB cable to record results directly to the Ketonix software. User profiles provide scores on various measures depending on exercise, food intake, medication. With different mouthpieces, multiple individuals can use the same device and set up their own profiles in the software. There are no consumables with the Ketonix breath analyzers, unlike most blood and urine testing devices.

Whether used in coordination with healthcare professionals for disease maintenance and monitoring, or by athletes, or people who want to lose weight, the simplicity and non-invasive nature of a ketone breath analyzer is appealing.