Ketones are acidic chemicals produced when your liver breaks down fat to be used as energy. Ketones play a central role in the keto diet, which trains your body to burn fat for fuel.
People without type 1 diabetes who are on a keto diet can monitor ketone levels as well. A higher level means your body is using fat for fuel—the goal of the keto diet.
In people with type 1 diabetes, the body has trouble using glucose for energy and turns to fat, flooding the bloodstream with ketones and turning it acidic, a serious problem. This is called diabetic ketoacidosis, or DKA.
Ketone levels are lowest in the morning and rise during the day, so test yourself at the same time for consistency. On a keto diet, aim for levels between .5 and 3.0 mmol/L.
If you have type 1 diabetes, an at-home blood ketone meter can keep tabs on ketones in your body. Normal levels are .6 to 1.0 mmol/L. Between 1.0 and 1.5 mmol/L? Call your doc.