Hi, Wanda!
I don't have much information of any links between weight loss and gum recession. I do know that periodontal disease (caused for the most part by plaque's presence around teeth and the body's sensitivity to it) can result in gum recession.
Periodontal disease is cyclical, it goes into remission and then in a spurt.
Another thing that contributes to recession is simply a thin jaw bone and slight movement of the teeth, which can cause the teeth to become exposed (the root, I mean it can only be seen in an x-ray) beyond the bone. In other words, pushed out slightly, the front teeth are no longer embedded in the jaw bone on the front (facial) side. Then, the gumline will follow the contour of the bone underneath, appearing to back away from the teeth and making the teeth look longer.
If the cheek has changed shape this can cause a propensity to bite the cheek sometimes.
Finding the bite "off" can often be just a normal thing that requires nothing to be done. It depends on how much and in what direction, also on whether there are spaces (missing teeth) anywhere.
I am getting long winded! E-mail me if you want more info.
-Connie