£14 billion worth of food was thrown out in 2010, unecessarily. One of the major reasons is the confusion between 'best before' and 'use by' dates.
'Use by' is a genuine health warning and once food has gone beyond that it should be thrown away. Yet with the exception of eggs, that is not true with 'best-befores'. They are simply the manufacturers' guidance of when it believes food is at its optimum quality. Beyond the 'best before' date, food is often perfectly edible for weeks, months or with some tinned food, possibly years.
In fact, 'best befores' are still allowed to be sold for consumption after that date and many people can buy perfectly healthy food at heavy discounts this way. There are local specialists and even an online store, Approved Food, which specialise in out-of-date stock.