Once alcohol enters the stomach, up to 20% of it can be absorbed there and go directly into the bloodstream. The remaining alcohol goes to the intestines and is absorbed there with the rest of the nutrients. The liver is the primary site for alcohol metabolism; this is why over-consumption of alcohol can lead to liver problems. Alcohol is then detoxified and removed from the blood through a process called oxidation.
So how can alcohol lead to weight gain?
Alcohol can lead to weight gain from the calories it provides. Alcohol contains 7 calories per gram, compared to 4 calories per gram for carbohydrates and proteins, and 9 calories per gram for fats. It's easy to forget that you can drink as many calories as you eat! In fact, some drinks can have as many calories as a meal, especially when you add the calories from any juice or soda that is combined with the liquor.
Research has also shown a 20% increase in calories consumed at a meal when alcohol was consumed before the meal – therefore contributing to weight gain.