As you know, the 2 weeks pre-op diet is to shrink the liver prior to surgery. If the liver is too large there is a chance that they may have to post-pone the surgery. I was on Opti-Fast during my 2 weeks. I was able to have 5 optifast shakes per day, unlimited sugar free popsicles, jello, crystal light, water, clear liquids. I had a cup of broth in the evening. It does take time to get used to this but you have to work with it. Remember, that the rewards in the long run are worth it. Plus, post-surgery you will continue to be on clear liquid diet for 1 week, then increasing to full liquids during week two.