Harms of eating expired food:
Food poisoning is generally divided into "biological" and "chemical" categories. Food poisoning caused by consuming expired food belongs to the "biological type" of poisoning. If people eat food contaminated by bacteria, viruses, parasites, etc., it will cause acute food poisoning, and even lead to acute infectious diseases.
In fact, the expiration time is not long food can also be eaten. For example, milk, whether it is refrigerated or not is more important than focusing on the shelf life. As for those who can not eat a meal of bagged food, despite a little bacterial contamination, eat just a little worse taste, the risk of injury to health is not high.