[MissDee]

I have a somewhat off-topic question.

I have always thought that food is either comprised of protein (4cals/g), carbohydrates (4cals/g), and fats (9cals/g). However, how does alcohol(7cals/g) fit into this grand scheme of classifications? Is it another category? If it is, how come whenever I look at the nutritional facts for alcoholic beverages there are always a high amount of carbohydrates? And furthermore, how come alcohol is not listed as a category along with carbohydrates, proteins, and fats on the back of nutrition labels. I have seen sugar alcohol on labels occasionally, are they at all related? Also, if alcohol does provide us with 7cals/g, wouldn't that mean, for example, they are superior forms of energy to carbohydrates?

Also, if it is a form of carbohydrate, how come it has a significantly different cals/g?

Thanks!

[Arkcon]

Briefly, animals are capable of using a number of organic macromolecules as an energy source, or as carbon skeletons to build biomass. (As distinct from autotrophs, which can build structures from simple molecules and energy.)  The numbers you have are not as cut and dried as the labels would have you believe, not all of the 4 cals/g of energy stored in protein is extracted by catabolisim, some is used to make biomass.  Even fats and sugars, and sugar alcohols, are used to make animal tissues.  At any rate, yes, ethanol provides more energy/gram than some other food sources, the downside is the toxicity.  Delicious, delightful toxicity.  (Sorry, we are very close to the weekend, and I have this particular flavor of consumption on my mind, right now.)

For you:  can you look up the italicised words, in a college level textbook, or maybe on wikipedia, so that you learn some more about these various topics?  It would be best if you stayed away from Google, for this search, there's a lot of pseudoscience out there on human metabolism, since people really do care a lot about diet, and will swallow almost anything.