Canned fish is a ready-to-eat canned product made from fresh or frozen fish through processing, canning, adding seasonings, sealing, sterilizing and other processing. Canned fish is somewhat nutritious. The general canning process does not cause loss of calcium and protein. Canned food is sterilized at high temperatures and pressures, which will cause the loss of some of the vitamins in the fish, but the calcium and proteins in the canned fish will not be lost too much due to high temperature and heating, so eating canned fish is somewhat nutritious. Although there is no harm in consuming canned food, it is still more advisable to eat fresh food. If you do pick canned food, pay attention to whether it is within its shelf life, and whether there are any leaking or bloated cans.