What do you pack?

Mixed nuts and dried fruit.

For the plane ride, just a bag of cashews that I buy at the airport. Besides that I do usually purchase food & drinks on the plane.

Is this question about packing for the rest of a vacation, or just for the plane trip?

I took it to mean the latter: emergency food for the plane in case you are stuck in a situation where there is nothing available.

Mixed nuts and dried fruit doesn't leak or weigh much, takes up a small amount of room in a bag or purse, but packs a wallop in calories and energy.

For those reasons I still use various nut-based mixtures for wilderness backcountry trips, as well as for in-transit emergencies. It's an important item on our travel checklist.

A bag of Trader Joe's trail mix that's resealable, and/or Twizzlers, and/or a thick European chocolate bar, like a Ritter Sport or Toblerone. Not usually all three.

I have a horror of being stuck for hours without food, as Nelson says. For real sustenance, we usually eat a proper sandwich at the airport before the flight, as we tend to be there earlier than strictly necessary.

Maroilles.

whathello, does that endear you to your seatmates?! Kind of like carrying a bag of durians into an elevator / lift.

Newbe, I should have mentioned we always carry a dark chocolate bar or two, as well as the nuts & fruit. After all, chocolate is the bottom of the food pyramid.

<After all, chocolate is the bottom of the food pyramid.>
Ha! Great minds think alike

And isn't emotional well being--virtually guaranteed as long as dark chocolate is around--as important as the physical??

I can't survive without chocolate.

We now have nuts (including suze's cashews, one of my favorites), dried fruit, cheese, and dark chocolate (for mental and physical health).

I could survive a week in the Wind River Range with those!

Hopefully the OP is getting the ideas that he was looking for.

Granola bars are my go to
Though the rules are weird, I once had a salad with me and the dressing in the packet was not allowed because it was a liquid and this was when the allowed amount must have been less than it is now. But it was ok for me to bring it through security when it was spread over the salad just not by itself in the container lol. You just never know