Are guys nervous to eat in front of women?

I've noticed that the guys I've been with always seem to have little to no appetite even if we've spent the whole day together haven't had anything. I feel weird bashing food when they aren't joining me but I'm a human who needs food!

Or they will eat but they like do something weird like sit behind me or slightly forward so that I'm behind them.

Is this a thing? Do guys get nervous to eat in front of me or am I being paranoid?