The first 3 moths or so are when you are likely to see the most extreme loss. Most continue losing at an excelerated rate for the first 6months or so.
But more important than that is you have to understand, this is not the "magic bullet" it is not gonna do his for you. It is a great tool, kinda like if Weight Watchers was a carpenters hammer, then the sleeve would be a wrecking ball. Though there is a huge difference between them there is 1 big thing they have in common. They're both useless without someone using them.
You are gonna end up finding that with all that restriction your gonna want to learn to nourish your body on your limited capacity. The way you view food is going to change completely. Embrace it, and try not to be too harsh on people around you that can still eat way too much. This is the hardest part for me.
As far as being able to eat too much, you'll be capable of that very early on. If you so chose. I could drink 5000 calories today if I chose to. But I just don't want that anymore.