I agree it is nigh on impossible to do two meal services on the short eastbound overnight flights. With a little bit of thought would it not be possible for passengers to pick up a bottle of water and snack upon boarding (for Y, and poss Y+), just have a quick round of drinks asap after take off and then have breakfast as the main meal served for those who want it (I usually sleep through it). If the timing was more appropriate it could be done the other way round, ie main meal after take off, with a breakfast box handed out immediately after the meal service (or even earlier). Arguably this would result in cost savings as you'd only be cooking one set of meals, and the boxed 'snack' needs only be light. Even in C or F I'm struggling to think of a time I've eaten both dinner and breakfast. Preflight dining and the Arrivals lounge usually help out there though.
Additionally, think of the extra productivity of Y pax upon their return as they gain more sleep, and potentially less jet lag.