This question really depends on the type of food. Some foods are added with preservatives so they can last longer, probably about 2 years at most. But I think this question is pertaining to easily perishable goods like bread and other dairy products. Usually they can last from 4 to 7 days. Beyond that, it is not safe to eat. Food spoilage is due to the action of bacteria eating up the nutrients. Generally, the more moist in the food there is, the ,ore short live is its expiration dates. This is because bacteria thrive more in moist places. It is a favorable condition for their survival.
