WATCH: Decode confusing expiration dates and eliminate food waste

LOS ANGELES, CA - How closely should you really follow food expiration dates? Well it turns out that expiration dates are generally guidelines rather than hard-and-fast rules. Of course your milk won’t go bad the moment the clock strikes midnight on the date stamped on its side, but the dates on the label can be tricky.

So here are some guidelines for when good food goes bad.

-A “sell by” date indicates how long a store should keep a product on its shelves. Foods can still be safe and delicious for several days longer if stored properly.

-A “use by” date or “best if used by” is set by the manufacturer and refers to taste and texture, not the foods safety.

-An “expiration” date is the only date related to food safety. If this date has passed DO NOT EAT IT.

Unfortunately, nearly 40 percent of all harvested food in this country ends up wasted, much of it by consumers who either waited too long to eat it or tossed it because they thought it looked bad, according to a report by PLOS One.

Dr. Gravani, professor of food science at Cornell University says that the look of food isn’t a good way to check for spoilage because bacteria are largely invisible.

So use your common sense, if that food in the back of your fridge for the past few weeks is slimy or smells funky then get rid of it! When in doubt, throw it out!