My T sometimes eats at the beginning of sessions, if she hasn't had lunch yet. I'm fine with it as it usually takes 10 minutes max and as I only see her monthly now we use this time to catch up and start really working when she's done.
I think one of the reasons I don't mind is because she's really lax on session length and will see me as long as I need it and will go over time if needed. So basically I feel like we're chit chatting while she eats instead of her eating alone and me being in the waiting room. It's not really using up session time.