This is due to acetone, a by - product of
acetoacetic acid which may be smelled on a person's breath.
It is well established in the «Art and Science of Low Carbohydrate Living» (Phinney, Volek) that when one has become «keto - adjusted» over the course of 4 - 6 weeks of low carb / high fat and protein living, that the type of keytones secreted in the urine,
namely acetoacetic keytones, reduce in concentration.
[emphasis added; note also that «acetone bodies» and / or
acetoacetic acid are what are commonly referred to today as «ketone bodies.»]
Although there are 2 other major ketones (acetone and
acetoacetic acid), BHB is the one that is able to cross through a wide variety of barriers in the body to get into the cells and be used as energy.
The other 2 ketones we find produced in the body include acetone and
acetoacetic acid.
In this life - threatening complication of diabetes mellitus, the acids 3 - hydroxybutyric acid and
acetoacetic acid are produced rapidly, causing high concentrations of protons, which overwhelm the body's acid - base buffering system.