We all keep leftover meals in the fridge to reheat the next day or another day to avoid food waste.

Yet, did you know that this habit is one of the most common causes of food poisoning? These remains can become toxic! Here are 9 foods that should not be reheated.

Many foods, even reheated several times, present no danger to the body. Nevertheless, some of them, when reheated a second time, can be toxic and harmful because they lose their nutrients.

To avoid any complications, here are the 9 foods that should not be eaten again.

1/ spinach
Although spinach is considered a healthy food, it should not be reheated or it may become toxic. Spinach should be eaten immediately after cooking. The main reason: they contain nitrates which when heated (again) turn into nitrites, a carcinogenic and highly toxic substance for the body.

2/ celery
Usually, this food serves as the basis for the preparation of soups. Like spinach, celery contains nitrates which turn into nitrites when reheated. If you eat a soup made with celery, you should eat it immediately. A word of advice: it is better to avoid celery (and carrot) in the soup because we tend to keep it for several days in the fridge and therefore reheat it several times.

3/ beet
Like the foods mentioned above, beets also contain nitrates which can be very harmful to the body when reheated.

4/ eggs
If you reheat fried or cooked eggs (in the microwave for example), they can be very toxic to your body and digestive system.

5/ chicken

Chicken can be extremely dangerous to health when eaten one (or more) day(s) after being prepared. The action of reheating the meat changes the structure of the proteins and can cause digestive problems. And unlike other red meats, chicken has a lot more protein. This is also the reason why people have a habit of consuming it cold. If you decide to reheat it, be sure to heat your dish at a lower temperature, for a longer period of time.

6/ mushrooms
When reheated, these foods pose the highest toxic health risk. As soon as they are prepared, the mushrooms must be eaten immediately or eaten cold the next day. If you reheat the mushrooms, you expose your body to many risks: digestive disorders, heart problems, etc.

7/ vegetable oil
Foods cooked in vegetable oils increase the risk of cardiovascular disease and cancer. Therefore, heating polyunsaturated oils like sunflower, corn, canola oil releases 4-hydroxy-trans-2-nonenal (HNE) which is a fatty acid toxin, leads to health problems, including including Alzheimer’s disease, Huntington’s disease, heart disease, liver problems and certain types of cancers.

8/ Rice
According to the Food Standard Agency, raw rice has dangerous bacteria microorganisms that are resistant even to cooking. Rice should be eaten right after cooking.

Solution: It would be better to freeze leftover rice instead of storing it in the fridge. Better yet, cook only the amount needed to avoid waste.

9/ Potato
The potato is a very convenient food to eat and cook. Thanks to its high nutritional value, it has many health benefits. However, all its benefits can be lost if you do not consume them the day they are cooked. This food will be toxic to your health when reheated.

Advice and methods of prevention
According to the USDA (United States Department of Agriculture), it is best, after saving leftover meals, to refrigerate and freeze them quickly. Freezing reduces the risk of food poisoning by protecting food from bacteria that can spread quickly.