Alcohol is metabolized differently than other foods and beverages. Under normal conditions, your body gets its energy from the calories in carbohydrates, fats and proteins, which are slowly digested and absorbed within the gastrointestinal system. However, this digestive process changes when alcohol is present. When you drink alcohol, it gets immediate attention (because it is viewed by the body as a toxin) and needs no digestion.
On an empty stomach, the alcohol molecules diffuse through the stomach wall quickly and can reach the brain and liver in minutes. This process is slower when you have food in your stomach, but as soon as that food enters the small intestine, the alcohol grabs first priority and is absorbed quickly into the bloodstream.
As the alcohol reaches the liver for processing, the liver places all of its attention on the alcohol. If you drink very slowly, all the alcohol is collected by the liver and processed immediately—avoiding all other body systems. If you drink more quickly, the liver cannot keep up with the processing needs and the alcohol continues to circulate in the body until the liver is available to process it. That’s why drinking large amounts of alcohol (or drinking alcohol quickly) affect the brain centers involved with speech, vision, reasoning and judgment.
When the body is focused on processing alcohol, it is not able to properly break down foods containing carbohydrates and fat. Therefore, these calories are converted into body fat and are carried away for permanent storage on your body.