Many people in Minnesota expect that breath tests will produce an accurate result that shows whether or not a person was driving while intoxicated. However, some of the more popular diet options can actually produce a false result on this type of test, potentially leading to serious penalties for people falsely accused. The keto diet is based on low carbohydrate consumption that pushes the body into ketosis, where the liver breaks down fat for fuel. When this happens, acetone emerges as a byproduct, and some of that is released as isopropyl alcohol.
This does not lead to symptoms of drunk driving, but it can still register on some breathalyzer tests as alcohol content, without distinguishing it from ethanol, the alcohol found in drinks. This is especially true if a person has had one or two drinks but is still below the legal limit; the isopropyl alcohol can lead them to blow a false positive on the breath test. Police breath test machines carried in their cars are more vulnerable to this kind of error. There is little evidence to show that these machines can differentiate between types of alcohol, especially if both are present in some quantity.
This issue can also affect people who drive vehicles fitted with ignition interlocks, whether due to a previous DWI conviction or a company policy. These devices may stop people from starting their vehicles even if only a small amount of alcohol, far below the legal limit, is detected in their breath. People on the keto diet have been stopped from driving their vehicles as a result.
In some cases, drunk driving defense attorneys have been successfully able to challenge police allegations for clients who are on the keto diet who were accused of DWI. People facing these types of charges can consult with a criminal defense attorney about their options.