Having done it as a size 8-10, 9 stone (dropping to 7 stone!) and as a 13.5 stone size 16-18, I can't say it has made much difference to the damage!
If it is gonna happen, there ain't nothing you can do to stop it!
I knew I was prone to stretch marks as I got them on my inner thighs when I was 9. Kids are cruel bastards, and I spent my pre-puberty, and puberty desperately hiding my legs! Now, they are nothing compared to my hips! Some of my stretch marks are over 1cm wide :(