From what I was told by my surgeon, protein is the most important food group post-op.For at least the first 6 months. It helps recovery, healing, preserves lean mass, keeps you fuller longer, and your body spends more energy trying to burn it. My doc told me post op no matter what you eat your going to lose weight,,But, if you don't get enough protein in, you will lose muscle as well as fat.. And the more you weigh, the more your going to lose initially.. So if somebodys weighs 400lbs, of course they will lose much more weight than somebody who is 260lbs..