My wife had GB surgery about 6 years ago. She dropped close to 100 pounds in a few months after that.
It pays to be careful though - you have a new 'tool' - but it can be disregarded and overrun. I know a fellow at work that had GB 10 or 12 years ago. He is now probably 400 lbs! I actually think someone said he weighed less before the surgery, than he does now! What happens often [and I know you know all this] is that once the bypass regrows, many people can eat sugar again. Also you stretch the stomach out and can be right back where you started. This guy can eat a horse! He never passes food up. I am saddened by the whole thing.
But - cheers to you! You have a new lease on life. Keep us posted.
Just a little update: I am down around 12 pounds now - depending on the time of day I weigh myself. I am drinking a lot of water, as the doc told me that high protein content can create renal issues if one does not drink enough. No prob with that - it is part of my strategy anyway. I have backed the percentage of protein down somewhat also. Still no sugar, or very little.
I might blow it a little tonight. Two thirds of my grandmunchkins are away for the night - and we might go out to eat. Still I think I will eat salad mostly anyway.
Peace
Jeff