And why does ATC always want to talk to me when I'm busily chewing aforesaid snack.
Biggles, You said it before I could!
Yep, muesli bars and drinks in bottles with sports caps work just fine...at least until you have to unexpectedly talk on the radio. And low blood sugar or dehydration and flying are not a good combination!
I'm talking f/w here, before anyone asks; if in a helicopter, unless it's a fancy expensive one with reliable friction/trim and autopilot/SAS, forget sustenance, or land in a field first. Unless you've learned how to grow a third hand.