No. I mean for starters, if you drink too much water in a short period of time, you will die of water poisoning. Basically your blood becomes too thin and your electrolyte levels go out of whack, and you die. Furthermore, weighing yourself is extremely inaccurate. You could weigh yourself twice in a row and get different weights. Also, you naturally weigh different amounts at different times of day for many reasons such as bodily functions and such. The best way to weigh yourself is to weigh yourself several times in a row and then take the average. But yeah, it's possible to gain a couple of pounds, but 6 is a bit extreme, maybe 1 or 2 though, max, without killing yourself.
