Inevitably, there will be some leftover meals, tea, in order to avoid waste, many people will continue to eat after the overnight, but with the improvement of living conditions, more and more people pay attention to health, many people worry that overnight water, overnight tea, overnight vegetables, overnight meat eaten after the adverse effects on the body, and even the overnight food will cause cancer, but in fact, not all overnight food can not be eaten, which 1. Overnight water: can continue to drink Generally speaking, whether overnight water can be consumed depends on the time and environment of placement, and has little to do with the overnight itself, and the nitrite content in the water is low and not carcinogenic. Overnight water is mainly affected by the environment, temperature, health conditions and other objective factors, such as high ambient temperature in summer, the rapid reproduction of bacteria, placed more than 8 hours of water, susceptible to airborne bacterial contamination, easy to cause gastrointestinal inflammation after drinking. Therefore, if the original water quality is clean, in line with health standards, after boiling, either overnight water or water placed for a long time during the day if it is well preserved, not contaminated by dust, bacteria, etc., are safe to drink. 2, overnight tea: not recommended to drink overnight tea first, overnight tea exposed to the air for too long, and not low-temperature preservation, the organic ingredients in the tea, sugar, etc. are easily oxidized by the air, reducing the nutritional value The tea will be less polyphenols and vitamin C content, as in the tea that has been steeped for too long, while providing nutrients for microbial reproduction and susceptible to bacterial contamination leading to rancidity and deterioration of the tea. If you continue to drink, the taste is not good, may also cause gastroenteritis, resulting in abdominal pain, diarrhea and other symptoms, not good for the body, so it is not recommended to drink overnight tea, tea can now drink. 3, overnight vegetables: can eat, but try to eat less overnight vegetables in the preservation period, if the high ambient temperature, susceptible to bacterial contamination, can be reduced to nitrite in the vegetable nitrate, especially green leafy vegetables, nitrite into the The body will generate nitrosamines, which is a carcinogenic substance, there is a risk of cancer, but a small amount of life to eat or not often eat overnight vegetables, this risk of cancer is low, and the body contains the ability to decompose nitrite, so overnight vegetables can eat mainly depends on whether health, safety, if the overnight vegetables are well preserved, and thoroughly heated can eat a small amount of some. However, it should be noted that whether placed for a long time or reheated overnight vegetables, will destroy vitamins, resulting in nutrient loss, and poor taste. In addition, overnight vegetables if improperly preserved, may breed bacteria, bacteria multiply, easy to affect the gastrointestinal tract after consumption, diarrhea, vomiting and other symptoms, especially cold dishes that can not be heated, more unable to kill the bacteria in them, prone to food poisoning. Therefore, it is not recommended to often eat overnight vegetables. Daily also pay attention to the use of better sealing performance of the preservation box to hold the leftovers, and then put into the refrigerator to preserve, can delay the growth of bacteria to a certain extent, to extend the consumption time. 4, overnight meat: fully heated can eat meat contains high-quality protein, fat, vitamins, minerals and trace elements and other nutrients. Unfinished meat placed in the refrigerator to preserve, short-term loss of nutrients is not serious, fully heated cooked, cooked through the overnight meat is edible. But also pay attention to the sealing performance of a good preservation box, and then put in the refrigerator to avoid contamination bacteria, resulting in meat food spoilage, food poisoning. Although, overnight water, overnight vegetables, overnight meat can be eaten, but also be careful not to leave it too long to avoid breeding a large number of bacteria and viruses, but also to avoid repeated heating, resulting in the loss of nutrients, etc.