Blood Alcohol Content (BAC)
Most jurisdictions will consider your blood alcohol content when deciding if you are driving under the influence. The readings cannot exceed .08 or you will be charged with a DUI, DWI or OUI (different acronyms used in the United States for the same crime). This is a well known fact, but there are many misconceptions as to what that number means and how blood alcohol readings are affected by drinking one alcoholic beverage versus another. There are also various misconceptions about the effect of food on your BAC readings.
Little Known Facts
Weight’s effect on BAC
When you drink, your weight affects your blood alcohol content. If you are a thin person, less alcohol is required to put you over the legal limit. That does not necessarily mean that overweight individuals have it easier. Alcohol tends to affect overweight people with high body fat a lot worse than people in good shape with a muscular body.
Food and Coffee’s effect on BAC
Food will not prevent you from having high blood alcohol content (BAC) reading. The amount of food that you ingest will only slow down the absorption of alcohol. Coffee will make you more alert, but will not lower your BAC reading. However, you will probably be more responsive to the flashing police lights behind you with a few coffees in your system.
Gender and its effect on BAC
Men are more alcohol tolerant than women. That means that the same amount of drinks taken by a man and a woman of equal weight will result in BAC readings that are much higher for the woman. Here is a concrete example:
- A man weighing 175 pounds drinks four beers in 2 hours will have a BAC reading of .06
- A woman with the exact weight and number of drinks will have a BAC reading of .08 which is considered driving under the influence
- A woman that weighs 135, who drinks four beers in 2 hours will have a failing BAC of .09.
These results would suggest that women will get results that are about a thirty-three percent higher than men for an equal amount of drinking.
Health and Medication
It is also known that taking medication can affect your results. Different medicines will increase the effects of alcohol and can even make you fall asleep while driving. You should consult with a doctor before mixing any medication with alcohol consumption. You will be putting your life and others at risk even if your BAC is lower than the legal limit. Linkages between mental health and BAC readings have also been established. If you suffer from stress or depression, your BAC readings may be higher.
Which is Worse, Beer or Hard Liquor?
Another popular misconception is that drinking beer is better than drinking shots. The truth is that a shot of whiskey will affect you and your blood alcohol content about the same as one beer or a typical glass of wine served in a 5 oz. glass.
More Facts on BAC
The ABCs of BAC
The National Highway Traffic Safety Administration has published a brochure called, “The ABCs of BAC.” It can be found on their web site at this address:
(Since their web site changes periodically, you may not find the brochure at the link provided. In that case you can go to the web site and use their search feature to find it.)
The brochure is structured in a question and answer format. For example, by reading it you will get the definition of BAC as “the amount of alcohol in a person’s body is measured by the weight of the alcohol in a certain volume of blood.” You will also find out that alcohol is absorbed and can be measured between 30 to 70 minutes after you drink.
The best part of the brochure is a table that shows the effects of various BAC readings on your ability to recognize problems and use your judgment properly.
On-Line BAC Calculator
Discovery Heath’s web site has an excellent on-line calculator that you can use to see what your limit is based on your weight, sex and how quickly you drink. You can visit the site here.
