"How should I respond when svelte friends pat their (small or nonexistent) bellies and announce they’re dieting to get rid of their 'belly pooch'?"

Question for an advice columnist.

Come on. This one is easy. Hijack the conversation into the topic of the word "pooch" to refer to their belly. That's such a goofball, infantile way to talk — way more annoying than the fact that they are aggressively pursuing their ideal body image. The subject of language has a little substance to it. The life of the mind! That's the thing. Let them take care of their bodies on their own time. Time spent with you should tinge toward the intellectual.

The Oxford English Dictionary defines "Pooch" — the noun — as "A dog, esp. a mongrel," as in "All you do is sink your teeth in my shoulder and make noises like a basket full of hungry pooches." (1924 B. Hecht Cutie vi. 46.). And then there's a football meaning — "Ever hear of a ‘pooch’ kick?" (1978 Gettysburg (Pa.) Times 15 Nov. 14/8.)

The verb "pooch" must be turning into a noun. "Pooch," as regional English, meaning "To pout or purse (the lips)," is pretty old...

1837   in J. F. Palmer Dialogue Devonshire Dial. iii. 18   Hog pooched out es moth, and look't glum, an didn't know what to zay.

... and more recently it's come to mean — with "out" — "To bulge or swell; to stick out"...

a1903   E. H. Goddard in Eng. Dial. Dict. (1903) IV. 577/1   [Wiltshire] Look at his pocket how 'tis pooching out.