I know on this show the folks are super big and have stretched out skin. They also lose skin very quickly and that is one reason that the skin hasn't shrunk to keep up. I also know folks that weight train and add muscle have less issues as the muscle fills up the loose skin. Some folks have less problems as genetically their skin bounces back better. Luck of the draw on that. It's easier if you are younger. Again cells regenerate faster. I honestly don't know if there is any type of ratio as to how many pounds of skin a person looses through surgery. I do notice a lot of ladies at the gym who have lost weight consistently complain about their stomachs but from what I see they have horrible posture and have rounded shoulders and that makes their tummies stick out.
Congratulations on losing so much weight.