Usually the fat ones in Bulgaria won't go dancing, because they are ashamed of their bodies or plain lazy. And why Amercan girs are fatter? I don't know, but I read this book recently that gave me some insight. I strongly recommend it.

http://www.amazon.com/Ultrametabolism-Simple-Plan-Automatic-Weight/dp/0743272560/ref=sr_1_1?ie=UTF8&amp;s=books&amp;qid=1256250395&amp;sr=8-1-spell