This comes up quite a lot, and there is plenty of info here if you do a search.
The problem I can see is, as a T2, you will be producing some insulin. In order to put on weight, you'll need to increase your BG to alevel where your insulin can't cope any more, and so the extra BG will be stored as fat (extra weight).
The problem I can see is - how can you put on weight, AND keep BG down in the proper range?
It's a tough one.
I know that if I wanted to put on weight, I'd have to up my carb intake. From my own experience, I know that eating sandwiches, pasta, jacket potatoes, etc... would cause me to put on weight quickly.
But I'm already overweight, and my weight fluctuates regularly - so the mechanism is already there for me.
As a T2 without a weight problem, I can't see that the mechanism IS there in your body to put weight on. Confusing, isn't it?