I said "other" because I would have the sim cook a new meal. I would not immediately trash it though...throwing it away can wait until a real meal is prepared.
I actually would never have this happen in the first places; I never have an active sim with such a low cooking skill prepare a meal desperately needed by the whole household. Getting a cooking skill with a few points on a sim is nearly my top priority in any household I play, and I do it when the sims are NOT desperately hungry, so that once it is a hunger-need thing, they won't be burning things.
I also always prepare meals ahead of time and have left-overs in the refrigerator. And, in desperate situations where there are no leftovers its easy enough to eat an apple (or whatever other produce is lieing around) to tide them over until a real meal that is decent quality is ready...as @Igazor said, you have quite a long time once the hunger sets in before it's actually damaging.
I don't think I've had a sim burn a meal needed to feed hungry sims since the original the Sims 1. . .