Why should you eat food before it best before date?

Answer 1

Best before date is given to make consumer aware about the freshness of the food. A food eaten after best before it might be good to eat but it might get spoiled and one can be sick. This is the last date before which we can consume the best quality.

Answer 2

Because it might get all mouldy and you can get sick, sometimes its still eatable before its out of date but its your choice to take the risk to eat it or not it depend what it is and how it looks :)