Exercise is great. Makes you health, your heart stronger, and improves your mood. As a tool for losing weight, it isn't all that useful. Exercise and the majority of people end up being hungry and eating a lot more than if they just sat around watching TV.
That said, I've never lost significant weight without exercise but then maybe it was the life style change in general that had more impact. That said, I may talk to my doctor about my options since I haven't been able to really exercise for the past couple of years.