I've flown a lot the last few years (within the cont. US) and for flights <3hrs (or thereabouts) all the airlines I've been on have cut food service (Delta/Song, JetBlue, USAIR, American, etc).
Delta doesn't even have '1st class' anymore (for the routes I've been on). For a while they had the bigger seats up front w/ no other perks. Recently, they've changed that to be the same seats as the rest of the plane you just get to board/depart (Zone1) quicker.
Anyway, there's food at all the airports so you can eat before the flight. Most folks can make it 3+hrs without having to eat, and if you can't you can always bring your own food on board and annoy your fellow passengers with it's aromatic goodness.
/While I've flown a lot, I do not cover every route on every plane on every airline, so, the above is just my experience but seems to match the general trend. You can always call the airline to see if they have a food service on the flight you are taking. It's possible that if you are flying from , say, 10a-1p they might have a lunchbox or something still.