Recently, I had a case with a person on a low carb diet that was arrested for Driving Under the Influence(DUI). The breath test was high for the amount of alcohol she consumed and I remembered the issue of low carb diets and elevated breath tests results. Low carb diets such as the South Beach diet and Atkins diet can increase the acetone in the body. Why is that important?

The breath test machine may confuse the acetone with alcohol. Therefore, it will give a higher reading on the breath alcohol test. In Attorney Lawrence Taylor’s blog post, Dieting Can Cause High Breathalyzer Results, he wrote about the effects of dieting and increased breath alcohol levels:

Fasting or radical dieting, such as with the Atkins diet, can also cause significantly elevated acetone. Studies have concluded that fasting, for example, can increase acetone in the body sufficient to obtain breathalyzer readings of .06% (this is cumulative — that is, the .06% will be added by the machine to any levels actually caused by alcohol or other compounds, so that a true breath alcohol of .03%, for example, would be reported by the machine as .09%).

The importance of this fact is, diet and other factors can influence breath alcohol testing levels. Do breath test machines detect this? I don’t know. The Tennessee Bureau of Investigation doesn’t even have an owner’s manual for the breath test machines that the citizens of the State of Tennessee have paid for.