Is it really dangerous to eat a food after its 'best by date'?

Summer vacations are coming to an end, and surely many people, upon their return home, stood in front of the refrigerator and meticulously checked that the food they left behind when they went away for a few days is in perfect condition. To do this, one would think, there is nothing better than to look at the "best by date" on the product. If it is a day old, throw it away. If not, it can still be eaten.

What many do not know is that this is a mistake. The best by date is, as its name might lead you to believe, simply an indication.

According to the Department of Agriculture, this label only shows "when a product will have the best flavor or quality. It is not a purchase or safety date." That is, any dairy product (those that usually include this label) will be fit for consumption even a few weeks past that date.

The same happens with expiration dates, which, according to the Department of Agriculture, are also an indication that determines "the last recommended date for the use of the product while it has the maximum quality." It is not a date that indicates safe consumption, "except when used in infant formula."

Nor is it an indicative date the day a grocery store is recommended to remove the product from its shelves (known as the "sell by date"). This metric simply "tells the store how long to display the product for sale for inventory management."

Finally, the agency also implemented a "freeze by date" which, like the other three, also does not indicate when that food should be thrown away, but rather what it marks is "when a product should be frozen to maintain its maximum quality."

So what do the expiration labels indicate? As the Natural Resources Defense Council's program advocate, Nina Sevilla, explained to USA Today, is simply an indicator of "when food will be as its optimum freshness."

"Date labels usually indicate when food will be at its optimal freshness. If you have food a couple of days past that date, it likely means it’s still OK to consume."Nina Sevilla, program advocate for the Natural Resources Defense Council.

As explained by the expert, who also fights against food waste, the best way to know if a food can be consumed is to rely on one's senses. They, Nina Sevilla detailed, are the best guide to know if food is in good condition.

"In most cases, your body has a natural, foul reaction to the taste or smell of spoiled food. Our reaction to spoiled food is evolutionary. We’ve fine-tuned our senses to keep us safe from ingesting things that might hurt us," said the expert, who is trying to reduce the nearly 40% of food that goes to waste nationwide.