So this a little O/T, but for trips where I'm not sure if I'm going to be fed (especially on MRs), I take a couple of Kashi Go Lean Oatmeal Raisin Cookie bars. They have them at Target for about $1 each (at least in Western WA) and they taste delicious (for a protein bar), have more protein and fiber than most of the other bars, and are pretty filling. Luna bars are also awesome (even though I'm not female, they're still great), but they're more expensive, not as substantial, and don't have as favorable a protein/fiber content.

As for the lack of meal service, this is pretty typical for the EWR-Florida market due to B6 and such. Although, for some reason, they seem to use a lot of 752's on the EWR/IAH-Florida routes, which is great if you happen to buy F or get an EUA.