It takes about two to three hours to completely metabolize one beer. Alcohol requires no digestion or preparation for absorption. It is rapidly absorbed when it is presented to the small bowel.
Food slows the process, diluting the alcohol and delaying gastric emptying while digestion occurs.
Six drinks in one hour without food will result in a very high blood level, while the same amount of alcohol with food, spread out over a six-hour period, will result in a much lower peak alcohol level. Both the peak concentration and the area under the curve of alcohol concentration over time will be lower in the slower drinker, since absorption occurs over a longer time period and metabolism of the alcohol will be occurring simultaneously. The larger the physical size of the drinker, the lower the blood alcohol level will be for a given amount of alcohol. Men have more active pre-absorptive metabolism of alcohol than women do. Rapidly ingesting alcohol avoids this first attempt at detoxification of alcohol.