To add to all of the helpful advice posted above, just to mention that you should BTC in any event. Once on the plane, you can have a look at the menu selection and if you like one of those (and subject to availability - but probably not a problem in F), you don't have to eat your BTC.

In fact, you can even (as I learnt from CGK ) for SQ12 (I don't know about SQ11), ask them to keep your BTC to eat for brunch prior to landing at LAX and then have an item from the dinner menu after departing from NRT.