I believe in the Swiss model. Serve a proper meal for free in C and make it available at a price in Y. People order a meal at booking in Y so you can manage wastage.

The C (or I guess J) proposition is then:

Flexibility (abandon the fully flexible Y ticket and just put these people in J)
Better ground service
Free food

Not going to work on the Shuttle I guess and may be there are lots of people out there who just do want a snack rather than a meal but the above would work for me.