If you run a search on stretch marks, it will show on every site (at least the ones that i've been to) that they can be caused by weight gain or loss. I guess it has a lot to do with collagen etc. I know that when I had anorexia and got the marks, my skin was so dry that if I made a fist, the skin on my hands would crack and bleed, so it is no wonder that I got stretch marks! I am covered in them, so much so that when making the plunge, lol, to learn to swim recently, I saved up hundreds of pounds to buy one of those olympic all-body suits, that cover you from neck to foot and also down your arms!!!!! Can you imagine how insane I look in the thing?? I would get fewer glances were I to get in naked. A learner, in an olympian racing suit. But hey, it got me into the water after 15 years of staying away from it. all the best, Doods.