As Transmster noted, it is possible to come home weighing more than when you went in. This is usually the case with an open surgery, or any type of RYGB where they fill your abdomen with fluid to make the organs move around more easily, so the surgeon can be more accurate with the incisions.
This is one reason why it's such a good idea to drink drink drink water, until you feel like you're gonna puke it all up. Don't try to get a balanced diet, don't worry about the type of fluid you drink, be it water, juice or vegetable. Your body is going through a huge traumatic change and the more you mess with it, the harder it will be on you. Just relax, watch movies or read, get up occasionally and walk around the house inside, then rest some more.
Rest contributes to healing.
I set that one thought out by itself because it is SO true. When you have an injury, you have to rest it. Moving it will only aggravate the process. And as to what you drink, this is a VERY important question for your nutritional team. You should have a team. If you don't, then just call the hospital and bug them with questions and soon you'll be getting calls from them in order to stop you from calling. I'm not suggesting that you be obnoxious, but that you get the attention you need.
We are here to support you and congratulate you. But to anyone who's reading this, your first line of inquiry has to be a medical professional.
As for the phases and recipes and types of foods, do a search of this group using the search feature. If you're thinking you'd love to eat a pomegranate, just enter the word into the search box and see what others have said about that.
The vast majority of people who've made this decision to allow surgery to help them because nothing else has, have succeeded and changed their lives. There is usually a small weight gain after surgery, but just stay focused on your personal goal and don't worry about it. Try to forget what bad eating habits you had before. This is NOT an overnight fix, but for most people, it is a permanent fix, and that's like hitting the lottery.
HAPPY NEW YEAR!