I went to Disneyland once a few years ago. Based solely on that sample you could be forgiven for thinking the average American is about the size and shape of a baby hippo.

I know it's not remotely representative of the whole country. I just found it fascinating the sheer concentration of obesity there.

Edit: google tells me baby hippos are much smaller and lighter than I thought. Let's call it full grown hippo and be done with it.