Hi, Karen
I've no personal experience, but some weight loss salons here provide their clients with progressively smaller foundation garments that cover the entire torso, upper arms and thighs.
According to a friend who did go to a salon the idea is to help keep the skin tight around the body and/or shrink it as excess fat is shed. I do know that she had no wrinkles or excess skin when she reached her target weight, but I don't know whether she just was lucky or whether the method really works—nor, if it does work, whether it works for everyone.