My doctor's guidelines are the same as yours. I think it may have to do with what they've found in their own patients, that seems to work. I don't know that for sure..just my thoughts. I will say that in following that guideline this week (had my surgery on Wednesday), I'm finding that I can't eat a full 1/2 cup of food and I may go back to liquids/shakes for a couple of days just to make sure all the swelling is down.