Leftovers when reheated can get spoiled when not cooked or stored right. Don’t reheat rice older than 1 day. Refrigerate cooked potatoes quickly and heat them thoroughly to avoid botulism. Refrigerate chicken and eggs within 2 hrs of cooking and reheat at 165°F. Boil spinach for 1 min to avoid cancer risk from its nitrites. Don’t use reheated oil at all; it can raise the risk of heart disease. Here are the 6 common foods you should not reheat in a microwave.

1)Eggs: There’s good reason most people eat their eggs freshly made. Besides tasting heaps better, it is also safer to avoid reheating eggs – unless you know how to do it right. Bacteria can thrive at temperatures between 40 °F and 140 °F and spoil the food or make you ill. Which is why leaving cooked eggs out at room temperature for a length of time and then reheating for use later is never a good idea.

2)Spinach: Spinach is a healthy food choice that can give you loads of vitamins and minerals. However, it is also a high nitrate vegetable. And while that’s fine in itself, these nitrates are converted to nitrites due to bacterial action – and this is not good if you’re already consuming a lot of nitrites and nitrates in your diet. All this can happen if you don’t store and refrigerate spinach properly. If the spinach has been pureed, the conversion is accelerated further.

3)Mushroom: Reheating Mushrooms will actually change the composition of the protein which can lead to severe digestive problems on consumption.

4)Potatoes: Potatoes come with a caveat on this list. Not all potato-based foods are problematic when reheated. It all depends on how well you store the potatoes after cooking them. Unfortunately, potatoes are the ideal growing environment for botulism-causing bacteria Clostridium botulinum. If you leave them out to cool at room temperature and don’t put them away to chill in the refrigerator quickly, you run the risk of allowing the bacteria to thrive. If you seal up the potato, it locks out oxygen, making it even better for these bacteria. This is also why storing cooked potatoes in foil has been linked to some cases of botulism.

5)Chicken: Chicken is another favored breeding ground for bacteria ranging from Escherichia coli to Salmonella that can cause you to fall sick with diarrhea or food poisoning.6 If the chicken you plan to reheat hasn’t been cooked and stored right, you run the risk of these problems.

6)Rice: Rice, like potatoes, can pose a risk when reheated or reused. This again is because of bacteria that can multiply if the cooked rice isn’t stored right or is stored for too long. Rice has naturally occurring bacterial spores that can sometimes survive the cooking process. Under the right conditions, like being left at room temperature, these spores multiply. Reheating them will unfortunately not be enough to rid the rice of the spores or the potentially poisonous substances produced by them. And that could bring on a bout of food poisoning.