Is there any difference between BA 25 (departing 18.15) and BA 27 (departing 22.30) on F class to HKG?

What I'm really asking is the catering service - will it be the same?

I know that I can order whatever I want whenever I want on F class (as long as I do it nicely ) but will the food be different?

Say, a full dinner for the earlier flight (BA 25) and only a lighter supper/snack for the later flight (BA 27)?

Thanks !!