While the BMI might be worthless I personally dont need any tests/polls/stats to tell me America is getting to be one fat lazy nation. Just open your eyes when your out and about.
http://www.letsgetreadytoramble.com/images/fatty.jpg
On the other hand there are some safetly benifits to being fat.
http://borderdogs.com/images/1/productimages/0508.jpg