Absolutely not. I worked in a theatre for a summer and I thought I had a pretty good work ethic. As long as you weren't rolling in with a pizza box clearly displayed, I'm not going to ask you for shit besides tickets. Do you have insulin in your backpack or an entire KFC dinner for 6? We will never know.
First off I wasn't going to until you said something, second off I'm probably still not going to because honestly unless you're blatantly eating a Big Mac in the middle of the lobby, no one gets paid enough to care. I'm a regular in my theater and I know that everyone knows.