say what?

Some of my co-workers and I eat in the lunch room around the same time. One particular co-worker greets me almost every other time with “You look tired.”

I am a morning person, so I try to cram as many meetings and assignments in before lunch every day. I am usually exhausted when I get to lunch, but do I have to be reminded of that every week?!

Is it cultural? This co-worker came to the US in the past year and perhaps has never heard of political correctness. I suppose it’s his way of making conversation, but what does one say to something like that?