At that point, you may have detectable levels of ketones in your blood. Blood ketone levels while on the keto diet typically range from 0.5 – 3.0 millimoles per liter (mmol/L) (1).

A cutoff of 3.9 ppm on the breath ketone analyzer maximized the Youden index, with a sensitivity of 94.7% and a specificity of 54.2%. Akturk noted the study was converted to be done at-home due to ...

Fruity-smelling breath is a sign of high levels of ketones in someone who already has diabetes. It’s also one of the first symptoms that doctors look for when they check for DKA.

INSIDER data editor Walt Hickey tried out the breathalyzer, and said that while it looked like he was using a vape pen, the breath test provided an easy way to monitor his keto dieting.