I've been able to score several of those 100 cal snack packs on longer flights, and often peanuts as well.

However, the best bet for those leaving DAL for onboard food is still LaMadeliene's, Chik-fil-A, Whataburger or Campisi's. I do NOT like to eat on a crowded flight after everyone arrives, so will often wolf it down before my fellow pax join me onboard. I've noticed that even the exit row stays open a bit longer when onions are on the menu.

Most airports will have some type of acceptable food to last a 4 hour trip, or arrive a bit early. We plan for airport dining when our grandkids join us, and it certainly makes the flight easier.