For the record, I haven't started my pre-op diet yet, so take the following for what it's worth. But I did read a post in another thread that the lady was drinking or eating (Jello, popsicles, etc.) every hour and a half. Whether that was large consumption of Water or jello or Protein shake etc.. That seemed to help her get through the day because she knew that every hour and a half she was going to have something and she planned it out and put her phone alarm to it. This sounded like a good idea, but again, I'm not in it yet so I'm sure it sounds great now!
Good luck to you!