I usually take something to share. On my way down especially! I didn't care if anyone else ate what I brought or not--so long as I had something to eat once I go there.
I would take small bits--very small bits of the other food but the vast, vast majority of my plate was what I brought.
"Be who you are, say what you feel. Those who matter, don't mind. Those who mind, don't matter." --Dr. Seuss