Do Expiration Dates Actually Matter? A Dietitian Breaks It Down

If you've ever thrown out a box of cereal because the date on the bag passed, you may have tossed perfectly good food. But if you've held onto leftover chicken a few days past its use-by date, that's a different story.

Registered dietitian Julia Zumpano with the Cleveland Clinic says there are three types of expiration labels, and knowing the difference matters. "Sell by" tells stores how long to display a product. "Best by," or "best if used by," signals when something will taste and perform at its best. "Use by" marks the last day a product is expected to be at peak quality. "It's ideal to know when that food is going to be best utilized by," Zumpano said. "Now, that's where it gets a little tricky. So that's just an estimate."

The rule of thumb, she says, is that pantry staples are generally forgiving. Dried goods like rice, pasta, and cereal, along with canned fruits, vegetables, and beans, are usually safe to eat past their listed dates. Perishables in the fridge are a different matter. Meat and dairy are where bacteria and mold are more likely to grow, so those dates deserve closer attention.

When in doubt, Zumpano says to trust your senses. If food looks slimy, discolored, or has visible mold, throw it out. Same goes for anything that smells sour or off, or doesn't taste right. "If it's past that date, using those senses, or if you feel better just tossing it, you can," she said. "But the goal here is to reduce food waste."