FOOD
The amount and type of food present in the digestive tract has the most direct and measurable effect upon the rate of alcohol absorption.
Alcohol consumed on an empty stomach is absorbed by most people within 15 minutes to 2.5 hours. If alcohol is consumed with a moderate amount of food, the range typically increases from 30 minutes to 3.0 hours. On a full stomach, ranges from 3 to 6 hours have been reported.
Stomach emptying time is a key factor in the absorption time of alcohol. Any substance in the stomach can act like a sponge and delay alcohol’s movement into the small intestine, where the vast majority of absorption takes place. Food delays the stomach emptying time of alcohol, and decreases the availability of alcohol in the blood stream. See Graph 2. Thus, the amount of alcohol that reaches the duodenum and the liver is highly variable.
The net effect on the representative BA curve is a decreased area under the blood alcohol concentration curve, a lower peak concentration, and an increased time to reach peak.
Peak BAC is lower with food in the stomach than without food. Since the maximum concentration reached is less, a person who has the lower peak alcohol level takes a shorter time to clear the alcohol from the body than one who has a higher peak level. Consumption of alcohol with food can increase alcohol clearance by 1 to 2 hours, and increase the rate of alcohol metabolism by between 36% and 50%, as compared to consumption on an empty stomach.
Although food changes the shape of the BA curve, it is difficult to predict the exact effect of a given meal consumed by a given individual. The type of food consumed appears to have an effect as well.
CIGARETTE SMOKING
Any substance that slows stomach emptying slows down absorption of alcohol that is consumed near the time of a meal. Cigarette smoking during or close in time to a meal has been found to slow stomach emptying and increase the time to reach maximum absorption.