My surgeon said he didn't originally have the pre-op diet requirement, but changed his policy when a patient gained TWENTY-FIVE pounds in the two weeks before surgery by having a non-stop food funeral. The doc didn't have a weigh-in policy before surgery at that time, so he didn't find out what the patient had done until after the procedure had to be converted to an open surgery because the liver was too heavy to lift out of the way laproscopically. Now he doesn't require weight loss before two weeks out, but he will not do the surgery if you don't lose some weight during those final two weeks. He did say he includes vegetables on the pre-op diet, which I haven't heard anyone else mention.