Haha. I know it is far-fetched from possible reality, but listening to their only popular song (in my opinion) "What makes you beautiful", there is a secret message as to the self-image helping of naturism. Sure, that probably isn't what they were going for, but it's an entertaining thought when you see the opening lyrics:
You're insecure
Don't know what for
You're turning heads when you walk through the door
Don't need make up
To cover up
Being the way that you are is enough
Everyone else in the room can see it
Everyone else but you.......
I don't know why
You're being shy
And turn away when I look into your eyes
Maybe I'm just bored or delusional, but it sounds like a pro-naturism concept, I picture a person trying naturism for the first time and being shy.......