Hamburger buns from last summer's picnic? Milk past its sell-by date?

Carrots that lost their crunch?

Countries around the world waste huge amounts of food every year, and the United States is one of the worst offenders.

37% of US food waste comes from individual households.

And roughly 20% of those food items are tossed because consumers aren't sure how to interpret the dates they're labeled with.

But most of those groceries are still perfectly safe to eat.

So if the dates on our food don't tell us that something's gone bad, what do they tell us?

Before the 20th century, the path between where food was produced and where it was eaten was much more direct,

and most people knew how to assess freshness using sight, smell, and touch.

But when supermarkets began stocking processed foods, product ages became harder to gauge.

In the US, grocers used packaging codes to track how long food had been on the shelves,

and in the 1970s, consumers demanded in on that info.

Many supermarkets adopted a system still in place today called open dating,

where food manufacturers or retailers labeled products with dates indicating optimum freshness.

This vague metric had nothing to do with expiration dates or food safety.

In fact, it's rarely decided with any scientific backing, and there are usually no rules around what dates to use.

So most manufacturers and retailers are motivated to set these dates early,

ensuring customers will taste their food at its best and come back for more.

This means many foods are safe to eat far beyond their labeled dates.

Old cookies, pasta, and other shelf-stable groceries might taste stale, but they aren't a health risk.

Canned foods can stay safe for years, so long as they don't show signs of bulging or rusting.

Low freezer temperatures keep bacteria that cause food poisoning in check, preserving properly stored frozen dinners indefinitely.

Refrigerated eggs are good for up to five weeks, and if they spoil, your nose will let you know.

And you can always spot spoiled produce by off odors, slimy surfaces, and mold.

Of course, there are some cases where you're better safe than sorry.

The USDA recommends eating or freezing meat within days of purchase.

Beyond their printed dates, ready-to-eat salads, deli meats, and unpasteurized cheeses are more likely to carry pathogenic bacteria that can slip past a smell or taste test.

And the dates on infant formula are regulated to indicate safety.

But while some of these labels work as intended, the vast majority don't.

In a 2019 survey of over 1,000 Americans, more than 70% said they use date labels to decide if food is still edible, and nearly 60% said they'd toss any food past those dates.

Restaurants and grocers often do the same.

To avoid all this waste, many experts advocate for laws to require that date labels use one of two standardized phrases:

"Best if used by," to indicate freshness, or "Use by" to indicate safety.

This solution isn't perfect, but some US researchers estimate that setting these standards at a federal level could prevent roughly 398,000 tons of food waste annually.

Grocers could also try removing date labels on produce,

as several UK supermarket chains have done to encourage consumers to use their own judgement.

Many experts also advocate for policies incentivizing grocers and restaurants to donate unsold food.

Currently, confusion around dates has led at least 20 US states to restrict donating food past its labeled date,

even though the federal government actually protects such donations.

Countries like France go even further, requiring that many supermarkets donate unsold food.

Regardless of what your government decides, the best way to prevent food waste is to eat what you buy!

And don't forget that your eyes, nose, and tongue are usually all you need to decide if food is fit for consumption or the compost bin.