Answer: Fats, carbohydrates or protein added to alcohol are processed in the body just as they are when delivered in foods. But alcohol itself is unique in that it cannot be converted to blood sugar, but instead must be processed as a fat in order to be used for energy. Alcohol entering the body is immediately processed for energy because there is no place in the body to store it. This is what initiates that strange but sometimes desirable feeling: if your body can’t convert it to energy as fast as you consume it, alcohol remains in the blood, including the in brain fluids, until it is metabolized.
With no storage depot, the body must preferentially choose alcohol as its energy source in order to dispose of the chemical before it reaches toxic levels. Once in the body, the seven calories per gram of alcohol are used for energy needs instead of stored body fat. So in essence, every calorie of alcohol taken in prevents a calorie of fat from being burned. But that’s only part of the story. At the end of the day, you can still lose body fat even if you drink regularly as long as your total calorie intake, including the alcohol, averages less than your calories burned.
Drinking alcohol on an empty stomach allows no interference with its absorption and thus it enters the bloodstream quickly, making it easier to get intoxicated if one is not careful about how fast they consume the beverage.
Unfortunately alcohol also stimulates appetite, and when you combine that with its un-inhibiting effect and a readily available supply of delicious, calorie-rich food, the results are often disastrous (to your waistline). In other words, drinking can often result in one not caring what or how much they eat.
And finally, alcohol itself supplies no nutrient value, only calories, and it robs nutrients from the body as it uses them to "fire up" the enzyme systems (alcohol-dehydrogenase) necessary for its metabolism. It is the depletion of these nutrients, including water, and the tannins contained in alcoholic beverages, that can contribute to the dreaded hangover.