Having been behind the scenes at a model photo shoot, I know how awesome they can make not-awesome people look. I always had perfect skin in all my photos, but I can tell you I had the worst skin as a teenager. Photo editing techniques are so freaking advanced these days it's not even funny. The point is, all the "skinny" models you see in magazines aren't actually that skinny. They're all just airbrushed to hell. So you should never feel bad about yourself wondering why those girls are so skinny and gorgeous in comparison to you, because likely they're not. And likely they have just as much cellulite as you.
See, they even do it to Jessica Alba:
http://shine.yahoo.com/channel/beauty/fashion-that-makes-us-sad-jessica-albas-perfect-body-airbrushed-to-something-skinnier-325704/ Just don't forget! Even though you know in intuitively, it's easy to get sucked into the fantasy lands that are fashion magazines.