I wanted to add a brief technical discussion to cover some questions that have been raised in this site’s short life.
Calories are derived from 4 macronutrient sources: carbohydrates, fat, protein, and alcohol. By (this site’s own) definition, a drink is 100% efficient if all of it’s calories are from alcohol, ie. there’s no carbs, fat or protein. So what happens when a drink isn’t 100%? Generally, there are residual sugars, which have not been fermented for one reason or another. Someone asked if it matters what the source of the sugars is for different types of booze, eg. whiskey (corn), rum (sugar), sake(rice) grapes (wine). The answer is: not really. Whether your carbohydrate is complex, like corn, it has been partially broken down by the fermenting yeast and there’s absolutely no fiber, so it’s not like it’s going to be any healthier than the residual grape juice in wine.
As far as the other macronutrients, fat is a non-factor unless you’re ordering a Mississippi Mudslide from Fridays. If you’re reading this site, that’s an unlikely scenario. As for protein, the barley in beer contains some, and the resulting beer contains anywhere from .3 to 2 grams per 12 oz, but meatheads shouldn’t get too excited. The protein’s biological value is probably near zero.
