Just sittin' around drinkin' with the rest of the guys/Six rounds bought, and I bought five. Roger Miller. Possibly my favorite song lyric of all time.
BYCU
How long can I survive on beer alone?
"Not more than a few months, probably. That's when the worst effects of scurvy and protein deficiency would kick in. (Liver disease is a serious risk of chronic alcohol use, but it takes longer to arrive.) If you kept to a strict beer diet–and swore off plain water altogether–you'd likely die of dehydration in a matter of days or weeks, depending on the strength and volume of beer consumed. There's plenty of water in beer, of course, but the alcohol's diuretic effect makes it a net negative in terms of hydration under most conditions."
Link.