For a combination of food safety and flavor reasons, it’s just not worth trying with these leftovers.

I know some people hate leftovers—for much of childhood I was such a snob about leftover pasta that I refused to eat it. I believe I once told my mother that it was a waste of a meal to eat reheated noodles. I have since apologized to her for this and many other hideous and/or exhausting things I did to make her life more difficult.

I have also since learned to love leftovers (yes, even pasta) and am an avid meal-prepper and food waste-reducer. That said, there are some things that you just shouldn’t reheat. Some are on the no-fly list because they’re just not…tasty. Others are against the rules because they have the possibility to make you sick. Here’s my list of leftovers that I will never reheat.

1. Mussels, Clams and Oysters

I feel like this is obvious, right? Shellfish just don’t hold up well, and they’re kind of finicky to begin with since they’re more likely than most other foods to make you sick. Undercooking can give you food poisoning, but reheat them in the microwave and they turn to rubber. Either way, it’s not good. Just skip it.

2. Fried Foods

The glory of fried foods lies in their texture! It’s all about the crispy, crunchy contrast with the creamy or soft. Without that, there’s very little point to the whole operation, and leftover fried things are almost always soggy. Sure, you can try reheating in them in the oven, but the result is nearly always a dry, flavorless piece of cardboard. If you love your fries, let them go.

3. Fish

This is another food that you just can’t reheat without ruining. The delicate flesh is prone to becoming overcooked in the first place, but a second round of microwave cooking will rob it of any pleasant texture. That, and you’ll also have to deal with your microwave smelling like fish.

4. Eggs

If you have leftovers from, say, brunch, and they include an egg, just scrap the old one and cook up a fresh one. It will refresh your meal and help you avoid the grossness of a rubbery, flavorless reheated scrambled egg.

5. Steak

Cold steak is delicious. And you’ve already put forth the effort to cook it to perfection—why ruin a great thing? Put your cold leftover steak on a sandwich or a salad and revel in its chilliness, instead of trying to reheat it and inevitably turning it into a sad, chewy lump.

6. Things that have been sitting out for a long time

When food sits at room temperature (like a casserole sitting out at a potluck, or a pasta salad at a picnic) it gives bacteria a chance to grow. Any temperature between 40° and 140° is what food professionals call the danger zone. If a dish has been sitting out in this temperature zone for more than 2 hours, it is significantly more likely to have grown some nasty bacteria. Refrigeration at this point is an option, but not a great one. Just let these dishes die.