I like Walmart, and I've noticed this phenomenon.... though much of my experience may just be noting geographic differences in obesity, as the Walmarts I visit tend to be in the less-urban areas of California, Nevada, or central Texas.

I'd love to see guerrilla-installation of some sort of weight-strain gauge under the entrances/exits of major eatery chains, so as to collect and publish data on the average weight of their customers.

I don't live near a Walmart, but this kind of physique is no stranger in NYC. Just yesterday at a supermarket I saw a pre-teen child about 4-ft high, who was bursting just like that.