I was steering my cart through Costco the other day, wondering whether to waddle to the aisle where they sell cashews by the quarter-ton or to the one with thousand-piece packs of chicken thighs, when an epiphany pierced the fog of my gluttony.

Actually, two epiphanies. The first? I needed to have kids, four or five or better yet a baker’s dozen. Only then could I take full advantage of the savings around me.

The second? Costco as much as anything else is why the land of the free and the home of the brave is also the trough of the tub o’ lard, our exceptionalism measurable by not only our G.D.P. but also our B.M.I. That’s body mass index, and our bodies are indeed massive.

I don’t blame Costco per se. I blame what it represents: an American obsession with size, with quantity, that manifests itself as surely in supermarkets and restaurants as it does on our highways. We drive minivans and sport utility vehicles; we rip into veritable feed bags of potato chips and wedge our steroidal Thanksgiving turkeys into refrigerators more capacious than some European cars. This doesn’t redound to our benefit.