We are in the same boat as I also started my pre-op liquid diet today. So far so good but I am drinking more water than usual to help with any hunger. I have my surgery on July 17 and am required to lose an additional 15 pounds by that date. Good luck.
HW 417 SW 360 CW 251 GW 250 Height 6' 5" Surgery on July 17, 2012