A well-known side-effect of a low-carbohydrate way of eating is the production of “ketone bodies” by the liver as a by-product of metabolizing fat to fuel the process of converting proteins into glucose to provide the body’s daily carbohydrate needs. Muscles, organs, and the brain all lap up the ketones as an energy source, and even function more efficiently on ketones than glucose. In fact, the human heart functions much more efficiently on ketones than on glucose, and this increase in efficiency is part of the reason a low-carbohydrate diet can be successfully used to treat those with heart problems.
But in the last few years, the easy availability of breath-analysis equipment both installed in vehicles and for police at roadside stops has brought with it a new danger for those living a low-carbohydrate lifestyle. The breathalyzer cannot distinguish between isopropanol as a by-product of ketone metabolism, and ethanol which is usually found in alcoholic drinks.
Analysis here: http://www.proteinpower.com/drmike/uncategorized/low-carbers-beware-the-breathalyzer/
Teetotaling pilot cleared of drunk flying charges following low-carb defense.
On the plus side, for those of us who like to imbibe from time to time, alcohol almost stops ketosis/lipolysis cold, resulting in a 73% reduction in fat metabolism for hours to days after drinking. So there’s little risk of isopropanol stacking with ethanol in your breath at that roadside stop.
I guess the message might be don’t low-carb and drive. Or if you do low-carb and drive, insist on a blood test rather than a breath test, since a blood test will tell the truth and not be fooled by isopropanol.
And no, this doesn’t mean you can carry around a carton of Slim-Fast or an Atkins Advantage shake with you all the time and get out of a DUI. A blood test will determine the truth quickly.