Is this normal in other parts of the county?
If your relationship with your partner is so shaky that having dinner with another female could potentially bring it down, something needs to be examined.
Everyone I have seen on my Facebook feed about it is talking about it positively. You don't have to make the exact same rule (re: eating, especially since there is a difference between getting a snack and having a four-course dinner), but the principle is very sound. I think it's a culture war thing that we never really thought about. It would feel like cheating to me to spend an entire day hanging out with a girl other than my girlfriend if I had one because some sort of light crush would inevitably form, and that's wrong, but unavoidable if you spend too much time together. That's not to say that you can't have friends of the opposite sex, as long as there are reasonable boundaries.
I have never taken you for a romantic before. Personally, I'm quite capable of "controlling" myself from developing romantic feelings, but maybe that's just me being picky.