It's specifically Beef that is the massive drain. Chicken/Pork/other meats are magnitudes of orders more water-conscious per calorie. (Pork uses 75% less, and is yet the most wasteful of water outside of cows/bovine)[1].

Beef is astoundingly wasteful of water. You could take an hour-long shower and it would use about the same amount of water needed for a pound of beef. [2] and [3].

[1] http://gracelinks.org/blog/1143/beef-the-king-of-the-big-wat...

[2] http://www.wsscwater.com/home/jsp/content/water-usagechart.f...

[3] http://blog.epa.gov/healthywaters/2012/03/virtual-water-real...