I think CX (Long haul) Y meals are pretty minimal with the extra waste they create. Just a few points.

1) The utensil packet contains the same items regardless of the meal type. Quite often the spoon isn't needed. I know this means having to stock different sets for different meal types, but someone could do the math to see if it was better or not. If there was a way for them not to come in the plastic wrap, even better.
2) Quite often there is a dish that is empty or just storing an item that could be placed on the tray. Apart from the weight and fuel burn, there is the needless need to wash these again.
3) Are the plastic tops to the salad and dessert dishes recycled? And the aluminium foil from the main dish? And the water bottles? Hope so. But I have a feeling most countries require airline food waste to be incinerated to prevent diseases etc.

I use an expandable water bottle on long haul flights. I fill it up at the airport and as I drink it collapses in size giving me more space back.