Ketogenic diets are extremely popular now, and with good reason. By cutting out carbohydrates and pushing the body into a state of ketosis, which forces the body to burn stored fat instead of sugar, people can lose large amounts of weight quickly, without feeling deprived or hungry.
And, unlike most other diets, alcohol is not forbidden on a keto diet. Rather, dieters are told that a couple of glasses of red wine or a vodka and soda water are fine, as the sugar content is low. Many keto dieters even enjoy that they get a buzz from alcohol more quickly when they're following the diet than when they're not.
But, not only should keto dieters be careful of overconsuming because their alcohol tolerance is lower on the diet, even teetotalers on keto should be wary of taking breathalyzer tests. Recent studies have shown that the chemical reactions that happen in the bottom during ketosis can trick a breathalyzer into thinking that you're intoxicated, and that can lead to you getting charged with DWI.
When your body is in ketosis, that is to say, burning your stored fat, your liver breaks down fat for fuel. This process creates acetone as a byproduct, and some of that acetone gets released when you exhale as isopropyl alcohol. If you take a breathalyzer when you're exhaling isopropyl, the breathalyzer might confuse it for ethanol alcohol—and you might get charged with a DWI. Even if you haven't been drinking.
The good news is that if you're arrested for DWI after taking a breathalyzer test and are brought to the police station, you'll usually be re-tested on a machine that is more advanced than what officers have in the field. The machines at the station use infrared spectroscopy and can tell the difference between isopropyl and ethanol alcohol. You may be able to request a blood test, as well. Blood tests can also tell the difference between the two alcohols.
Keto diets aren't the only thing that confuses breathalyzers. Diabetes, GERD, and acid reflux can all also cause a false positive on a breathalyzer test.
So, what should you do? If you're pulled over, know you're sober, and the officer wants you to take a breathalyzer, politely tell him or her that you'd like to be taken back to the station to use the infrared spectroscopy machines, and call your lawyer.
If you've had a sweetened drink or a beer, you may have consumed enough carbs to shut down ketosis. In that case, the breathalyzer will only register the actual alcohol you've consumed, and that's not likely to be enough to put you over the legal limit. And if you're really concerned, drink a glass of orange juice or eat a few pieces of candy before you drive. The extra sugar will throw you out of ketosis and the breathalyzer will only register the alcohol you drank.
And, of course, if you think you've had a little too much to drink, ketosis or not, just don't drive.