I am 1 week and 1 day out from surgery. I didn't feel hungry for the first 4-5 days, then out of nowhere hunger struck! I made sure I ate atleast 3-4 times/day. Here's a tip-Greek yogurt. It is low calorie/fat and one thing of the greek yogurt has 16gms of protein. I use this for my smoothies. Also, boost shakes are just enough to fill me up and have 16gm protien a piece. Good luck.