Whats amazing to me is that who ever you talk to has a different pre op diet based on who their doctor is. My doctor didnt put me on a pre op diet, but once I went in for my initial appointment she did tell me that part of the process was to lose 20 lbs, which was to help shrink your liver and , the less you weigh ideally the fewer complications you might face in surgery. The only prop instruction I have is a liquid diet the day before the surgery and NPO after midnight. I started this journey on July 14 and My surgery date is in 5 days, November 19. To date I have lost 34 lbs, by drinking only water (oh, with the exception of my daily non fat sugar free vanilla upside down carmel machhiatto from starbucks) and really limiting my carbs and fried foods (not cutting out completely). I started with one small change at a time and made changes that I could stick with. Plus uping my previously non exsistant workout schedule to 3-5 days a week on the treadmill for 45 minutes. Is it easy? Absofrickinloutley not! But you can do it. Small changes on at a time towards a healthier life style, because face it thats what we have to do. We have to make changes to what and how we eat. You can do it, but I would start small and make changes that you can stick with the kind that you are going to have follow after surgery. Good Luck!