Is Desire. You have to want it. I watched a couple of episodes of Extreme Weightloss this weekend and Chris Powell said those words just before he, for the first time ever, walked away from a client. It was pretty moving.
I think for me, the difference is before, I would say something like, "I'd really like to be thin/healthier/whatever," but I never made a change. It really comes down to desire. You have to WANT to be healthier. You have to WANT to take care of yourself.
It really is a lifestyle change. You have to decide that your long term health and well being mean more to you than that cheeseburger or bag of chips.. or whatever it is that you put into your mouth that keeps you overweight.
The key to transformation is desire. You have to want it. Well, folks, I want it. I want it really bad. Several things in my life convinced me that have to make this change. What convinced you? Or are you even totally convinced yet? I'd love to hear what got you motivated.