Factors that Affect BAC

Posted by on

There are many factors that can affect your blood alcohol content (BAC). In fact, may of these factors are completely unrelated to alcohol. Age, gender, body type and metabolism can all contribute. Before we get too far ahead we should first discuss what BAC is. Blood alcohol content, or BAC, is a measure of alcohol that is present in your blood based on the volume of alcohol that has been consumed over a given period of time. Some of you may be familiar with BAC calculators or charts depicting how many drinks you can safely consume for your height and weight within a specific time range, however, the fact of the matter is that many variables influence your BAC. With that in mind, you can see why it would be dangerous to rely on such methods to determine a safe range of consumption.

While alcohol is the main factor in BAC levels many are not aware of other factors that can contribute:


As you grow older the effects of alcohol intoxication become more pronounced. Typically the BAC level in older adults rises more than it does for young adults by as much as 20%.


Men and women will often experience different BAC levels even if they are the same age, same weight and consumed the same volume of alcohol over the same time span. This is due in large part to the fact that alcohol is highly water soluble and women typically have lower water content in their bodies than men which results in a higher BAC level. Enzymes in the stomach that assist in breaking down alcohol also differ between men and women, with women having a lower quantity, which can cause higher BAC levels as well.

Rate of Consumption

This may seem obvious, but the faster you consume alcohol the faster your BAC will rise. As the number of drinks increases so too will your blood alcohol level. This can also be affected by the size of the drink. A larger drink will contain more alcohol than a smaller drink (depending on the strength of the drink, of course) which will affect the rise in your BAC level.

Strength of the Drink

Not all drinks are equal in strength. For example, in most instances a shot of liquor is going to contain a higher percentage of alcohol than a can or bottle of beer or a glass of wine. As a result, the stronger the drink the more it is going to affect your BAC.

Body Type

Body type can influence how alcohol affects you. Those who weigh more typically have more water in their body. Water has a diluting effect on alcohol making it not as strong (for example, allowing ice cubes to melt in a drink over time will have a diluting effect). For this reason, it is not uncommon for those with larger body types to not feel the affects of their alcohol consumption in the same manner as those with smaller body types. This obviously does not apply to everyone due to the fact that even two people with similar body types could respond to their alcohol consumption differently. Body type should never be used as a measure for how many drinks you can safely consume, this is only meant to demonstrate that alcohol can affect body types in different ways.


Most people only think of metabolism in terms of weight loss or weight gain. Our metabolism is responsible for our body’s energy needs because metabolism is the process by which our bodies convert the food and drinks we consume into energy. Even when we consume alcohol our bodies have to do something with it. Metabolic tolerance refers to the rate at which alcohol is processed by the body, and this tolerance varies from person to person.

“Tolerance that results from a more rapid elimination of alcohol from the body is called metabolic tolerance. It is associated with a specific group of liver enzymes that metabolize alcohol and that are activated after chronic drinking. Enzyme activation increases alcohol degradation and reduces the time during which alcohol is active in the body, thereby reducing the duration of alcohol’s intoxicating effects.” – National Institute of Alcohol Abuse and Alcoholism


Food is a contributing factor to your BAC level. If you consume alcohol on an empty stomach your BAC, in most instances, will be higher than a person who has eaten before drinking. Food tends to keep alcohol you have consumed in your stomach for a longer period of time and as a result slows the absorption into your bloodstream.

Carbonated drinks can be another factor. Carbonated drinks such as sparkling wine or champagne or alcoholic drinks that are mixed with soda (for example Vodka mixed with a popular energy drink) may increase the rate at which alcohol passes through your stomach and into your bloodstream resulting in a higher BAC.


Mixing alcohol with medication can be dangerous and even deadly. Many medications react negatively with alcohol and can intensify the effects of alcohol. Most medications that are known to have a poor reaction when mixed with alcohol will be labeled with a warning. However, if you are uncertain you should always consult your doctor or pharmacist prior to consuming alcohol if you are taking medication.

While these factors all contribute to your BAC level, alcohol intolerance may also cause adverse reactions in certain individuals. You should never rely on counting drinks you have consumed, using calculators, or referencing any charts to ensure you are safe, there are too many variables that can affect you. Knowing more about factors that contribute to your BAC level will help you make educated decisions on safely consuming alcohol.

Factors that affect Blood Alcohol Content (BAC)
Article Name
Factors that affect Blood Alcohol Content (BAC)
Many important factors including food, medication, gender, strength of drink, and body type can affect your blood alcohol concentration (BAC) levels.

If you have any questions regarding the services provided at the Law Office of Gregory W. Fox,
or would like to schedule your free initial consultation, please contact us today at (559) 222-5800. Hablamos español.