I think a lot of us have done convoluted routings and lengthier trips for one reason or another (extra miles, extra Tier Points, different a/c, different routing, fun of flying, etc) so the routing you describe is relatively 'understandable' but I am with others here, I wouldn't change my F flight with BA just so that I got an extra slightly bigger meal - you won't be left hungry either way.

now, if you were toying with a LAX / SFO routing anyway, fill yer boots of course. But as much as I love flying, I'd not take a detour for a BA meal (unless there were other reasons for doing so as well).