Got OLD Milk?

"I like to make sure it hasn't been here too long," says Nelda Carder. She checks the expiration dates, especially for foods like meat. "I'm too afraid of food poisoning," says Carder.

The expiration date is your quality assurance for peak freshness and nutritional value. But there are two kinds, the "sell by" and the "best if used by" date. The sell by date is found on foods like milk, eggs and meat. You need to abide by those dates pretty closely. "If you use the sell by date on perishable foods you need to watch it.  If not you get into food poisoning, bacteria problems and you can get sick," says dietician Kay Litwicki.

But for non-perishable foods like cereal, you'll find 'a best if used by.' There's no need to throw these out after the date. This is more a freshness guarantee than a safe to eat guarantee. "If you use it beyond that date it's fine. There's just no peak of freshness guarantee," says Litwicki.

How you grocery shop also affects your expiration date. For perishable foods like proteins, and dairy products, keeping them out of the cold for more than 20 minutes means they may go bad even before the expiration date. "Things like eggs and cheese and milk-- pick those up last when shopping and put them in the refrigerator first," says Litwicki.

Unfortunately expiration labels are not uniformly regulated so food producers end up using all different labels with different meanings. So the best test of when to toss may just be your own common sense.