It's a pity to dump it. How can leftovers not be wasted?

Loss of nutrients, leftovers left for a period of time, and then heated and stir-fried, food will lose more nutrients, it is difficult to achieve good nutritional effects. It will breed bacteria. When hot food is exposed to the air and gradually cools down, some harmful bacteria will be produced. These harmful bacteria attach to leftovers and start to multiply, producing some substances harmful to human health. Regarding the generation of nitrite, there is a saying on the Internet that after the leftovers are left for a period of time, they will produce a substance harmful to the human body-nitrite. If you eat it once in a while, there won't be a lot of nitrite in it, and it won't cause harm to the human body.

Actually, this is not right. The possibility of nitrite produced by repeated heating of meals is very low, so the nitrite content in leftovers can be ignored, mainly because the number of bacteria in food increases with the extension of storage time, which may make people sick.