Low carbohydrate/high protein diets have been popular for decades as a way to lose weight quickly. Whether it is the keto diet, Atkins, Paleo, or some other name for a ketogenic diet, you might be surprised to learn that one side effect is a false positive on a breathalyzer at a DUI stop.
How Keto Diets Work – in a Nutshell
These diets allegedly burn off fat by converting fat into ketone bodies and fatty acids. If you are not on a ketogenic regimen, your body typically uses glucose for energy. Keto diets are very low in carbs, including those that contain glucose. With the keto diet, your body can’t burn glucose, so it burns ketones for energy.
You might wonder how you could end up in jail for following one of these trendy diets. A low-carb diet itself is not against the law, but your body’s chemistry could register a false positive on a DUI breath test. A prosecutor could use the false positive result as evidence against you to get a conviction for driving while under the influence of alcohol. Also, a keto diet could cause symptoms that make you appear intoxicated to the officer.
How You Could Fail a Field Sobriety Test Because of a Keto Diet
You might not have even had a sip of alcohol before getting behind the wheel, yet a police officer might suspect that you are impaired by alcohol. When you severely limit your intake of carbs and increase your protein consumption, your body eventually goes into what is called a state of ketosis. Your body will have a very high level of ketones.
A person in a state of ketosis can develop the side effects:
- Your breath could smell very sweet or like alcohol.
- Your face could become flushed.
- You might become sluggish.
- Your movements could become uncoordinated.
- Your face could become red and flushed.
- Due to the diuretic response to ketosis, you could become dehydrated and very thirsty.
Let’s see that you got pulled over for speeding. The officer walked over to your car and talked to you. When you responded, the officer smelled what he thought was alcohol on your breath. Your face was red and flushed. Your speech was sluggish, and you were a little clumsy when reaching for your driver’s license and registration. All of these factors were caused by being in a state of ketosis.
Based on your conduct, the officer felt justified in making you take a breathalyzer test. This is where things go from strange to downright bizarre. Without drinking a drop of alcohol, you might fail a breathalyzer test and get arrested for a DUI.
Why Keto Diets Can Register a False Positive on a DUI Breathalyzer Test
DUI breathalyzer testing equipment can only perform within the limits of its design. Some DUI breath testing machines incorrectly read ketones as alcohol on the breath. The chemical composition of ketones is similar to isopropyl alcohol, also called rubbing alcohol. It can be lethal to drink isopropyl alcohol, but a breathalyzer might not be able to distinguish between isopropyl alcohol and ethyl alcohol, which is the kind of alcohol that people drink.
If the machine mistakes ketosis breath for alcohol, the test result can be a false level of blood alcohol concentration (BAC) that exceeds the legal limit. In other words, the prosecutor would have strong evidence to support a conviction of driving while under the influence.
Other Medical Conditions Can Cause Ketosis that Masquerades as Intoxication
There are multiple medical conditions and behaviors besides a high-protein/low-carb diet that could lead to the body producing an excessive amount of ketones. In these situations, a person could mistakenly get arrested for a DUI because of the appearance of intoxication from being in a state of ketosis and from registering a false positive for a high BAC level on a breathalyzer test.
- A person with diabetes cannot produce enough insulin or does not respond well enough to the body’s insulin for the body to use glucose for energy. The individual can build up dangerously high levels of blood sugar and make too many ketones for the body to flush out. The person could develop diabetic ketoacidosis, which can be fatal. The symptoms of diabetic ketoacidosis are the same as being in a state of ketosis from a ketogenic diet.
- An individual with an eating disorder, like anorexia or bulimia, can go into a state of ketosis. When the body does not get enough carbohydrates due to an eating disorder, diarrhea, fasting, or starvation, the body burns off its fat stores for energy. Using fat instead of carbohydrates for energy can cause the liver to produce a high level of ketones, resulting in ketosis.
- Hypoglycemia, also called low blood sugar, can cause many of the same physical symptoms as ketosis, leading a police officer to think that the person is intoxicated. A person with diabetes could become hypoglycemic if their insulin dose is too high. Some medications can cause hypoglycemia, as can endocrine disorders or diseases of the liver or kidneys.
If you have any of these medical situations or were on a high protein, low carbohydrate diet that caused a state of ketosis, you will want to speak with a DUI defense lawyer about using the keto defense in your case. It is a significant challenge to persuade a jury that a diet or medical condition could cause a false positive breathalyzer result and make a person appear intoxicated. You want to work with a criminal defense lawyer to fight this battle.
Strategies for Fighting a Ketosis-Caused DUI Charge
The way to go about challenging a DUI charge for a field sobriety test or false positive breathalyzer analysis will depend on the specific facts of your case. As we learn more about conditions that can cause ketosis and how ketosis affects the body, it is likely that we will develop even more techniques for defending people from unfair arrests and criminal charges.
Countering the Physical Appearance of Intoxication from Ketosis
If the police report describes physical symptoms, like the smell of alcohol, a red or flushed face, and a lack of coordination that the officer observed in your appearance at the traffic stop, the keto defense could explain that part of the police report. Your DUI attorney could present evidence that the diet you were on or a medical condition from which you suffer causes the same symptoms noted in the police report.
A letter from your treating physician could be extremely valuable. The letter should identify the medical condition or diet and explain briefly how your situation can cause a false positive breathalyzer test result and the specific symptoms the police officer noted in the traffic stop and arrest report.
It would be quite expensive to pay your doctor by the hour to come to court to testify, but a letter might get the ball rolling. The prosecutor might want to take your doctor’s deposition or hire an expert for the prosecution. As a practical matter, however, the prosecutor might decide to drop the charges.
Attacking A False Positive Breathalyzer Result
You might decide to try to prove that you had isopropanol from ketosis in your bloodstream or on your breath at the time of the breathalyzer test instead of ethanol from alcoholic beverages. It is possible to distinguish isopropanol and ethanol by using gas chromatography of the defendant’s blood sample. You will need to obtain and preserve a blood sample right away for this differential analysis because alcohol dissipates in the breath and bloodstream in a matter of hours.
Another possible option is to attack the breathalyzer machine itself. Research studies reveal that some breathalyzer devices are substantially unreliable even when measuring ethanol. The same sample BAC result could range from 0.09 to 0.17, for example, depending on which breathalyzer the officer used. In other words, if you can show that the particular breathalyzer unit the officer used is not reliable, you could discredit the validity of the breathalyzer test results.
Even identical models of the same brand of breathalyzer could achieve inaccurate results because of instrumental or procedural problems. In other words, the breathalyzer could be flawed, there could be maintenance issues with the device, or the officer might have used the machine incorrectly. It is usually best to have an expert evaluate the actual unit the officer used at the time of the DUI arrest.
How to Fight False and Unfair DUI Arrests and Charges
Getting charged with and convicted of a DUI can have far-reaching consequences that damage your career, your finances, and your reputation for many years. Challenging DUI charges based on ketosis causing physical symptoms that look like intoxication or a false positive breathalyzer test is sophisticated work, not for amateurs.
If you find yourself charged with a DUI wrongfully because you were in a state of ketosis from a ketogenic diet or a medical condition, you will want to have a DUI attorney at your side from the very beginning.