I never used to have this problem--

I know I could just go out on the 'Net and look this up--or at least check out a lot of what the blurp is--but I'm wondering out loud: what the fuck is "trans fat"? When did that one enter the lexicon? I like to think I know something about chemistry and nutrition, though I'm no expert. I know the difference between saturated and unsaturated fats (hydrogen concentration), between LDL and HDL (low-density lipids are bad for you, high-density lipids are good for you). Along comes "trans fat", and I'm seeing it everywhere. Or, rather, I'm not: I've only found one food product so far that actually contains any (it was a frozen pizza--which I ate anyway, goddamn it all).

The whole "trans fat" issue is, at least it seems to me, some kind of nutritional straw man argument: it's something that we can all agree is bad, however ill-defined, and unites us all in the knowledge that our current available diet doesn't contain any.