Okay, here is a valid answer from someone in the biochemistry field (me).
I posted this in another thread about a month ago, so here it is:
Acetaldehyde is what gives you the hangover symptoms because it is more toxic than the ethanol from the alcohol you ingested. So ethanol is oxidized in the liver by alcohol dehydrogenase which can then be converted through the enzyme acetaldehyde dehydrogenase to acetic acid. Our bodies do the cycle kinda backwards because plants convert pyruvate into acetaldehyde for alcohol fermentation using pyruvate decarboxylase which will eventually be converted into ethanol through some other pathway.
So, what all this means is, your body nearly stops protein synthesis and other very important biochemical sytheses because the main focus shifts toward eliminating the toxic compounds that are now in the body (ethanol and acetaldehyde). Even worse, cortisol levels become elevated from the increased stress on the body.
Also, beer is highly estrogenic. When people drink a lot of beer, they develop a beer belly and man boobs. Increasing estrogen and carbs from liquor simultaneously will cause the body to store carbs in the 2 places where women retain fat the most, the belly and breast region. Estrogen is very sly, and even though a male may not have overall high levels of estrogen, the constant spikes in estrogen from repeated drinking will cause estrogen fat retention (and water).
There is more to it, but that is as simple as I can make it.
Oh, and NO, alcohol is not healthy in moderation. If you are into lifting, you can do nothing worse than ingest alcohol, which is proven by how it changes the priority of important biochemical pathways for toxin removal.
