You know, this is probably a tongue in cheek thread, but my daughters are by NO MEANS even chubby, however, they've got fairly dense muscles, due to extreme activity levels (tree climbing, chasing the dog, etc., I'm not one of those crazy sports moms) and they get a LOT of crap because they do not have the common"toothpick legs" of their peers, making "skinny jeans" an impossibility.
Now, I would say that in the wild, they'd have a better chance of 1. outrunning a predator (at east compared to the or 2. kicking the toothpick legged kids' butts (lol) but in the social jungle this causes them much grief. And since skinny jeans are pretty much "the norm" it is hard to find pants that don't assume all kids are built like Jack Skellington.
(or, conversely, the Buddha... we are certainly becoming a nation of extremes, in more ways than one....)