Gaining

Honestly it mostly depends on your skin. I'm very very prone to stretch marks and had them even before I got fat just from my body growing. Some people are more prone than others, some get them lighter/heavier.

I've hear Bio-oil helps, as do other creams but those usually take daily applications (at least) over a while to see results. Doable but can get expensive depending on what you're buying-even if the thing works for you or not.

The best thing to do would be to learn to love them. It's hard to do, I still struggle with mine, but it's doable.

I have put on nearly twenty pound in the last five years, since I retired from the military reserves. I do not have any stretch marks. I think, as pointed out in this thread, you are prone to them or not. I have very smooth skin with little or no hair on my body. I did not use any oils or creams either.