It is a tradition in China to take a dish called longevity noodles o sau mein to ensure that in the years to come we will have a prosperous and healthy life. For this reason, cutting the noodles or biting them before putting them in our mouth is a sign of bad luck, since it is considered that by doing this we are "shortening" our life. You have all the information in: «Chinese traditions«.
You have all the information in: "Chinese traditions".