Researchers at Ohio State University performed one of the first data-driven glimpses into the refrigerators of regular Americans. Their analysis shows that Americans throw away about half the food they expect to eat on a given week. One of the prime reasons is confusion around ambiguous labeling such as “use by” and “best by”.

Brian Roe and colleagues at Ohio State University surveyed hundreds of Americans about what drives them to throw away food from their refrigerators.

“We wanted to understand how people are using the refrigerator and if it is a destination where half-eaten food goes to die…That’s especially important because much of the advice that consumers hear regarding food waste is to refrigerate (and eat) leftovers, and to ‘shop’ the refrigerator first before ordering out or heading to the store,” Roe said in a statement.

The findings show that Americans discard much more food than they expect upon purchasing. For instance, the participants expected to eat 97% of the meat in their fridges but only finished half before dumping the rest in the bin.

Results were similar for other products. The participants said they’d eat 94% of the vegetables they’d purchased but consumed only 44%. They also thought they would eat 71% of the fruit and 84% of the dairy in the fridge, but consumed only 40% and 42%, respectively.

Unsurprisingly, the primary reason why people discarded their food was concerns over food safety. Odor, appearance, and dates on the label indicated whether a foodstuff was disposable or not. Regarding the latter, the researchers found a lot of confusion among the participants.

“No one knows what ‘use by’ and ‘best by’ labels mean and people think they are a safety indicator when they are generally a quality indicator,” Roe said.

As a rule of thumb, Roe says that “best if used by” translates into “follow your nose” — in other words, even though the date has passed, the food should be perfectly fine as long as it smells the same. “Use by” translates into “toss it” after the date passes.

The researchers also found that people who more frequently cleaned their refrigerators were also more likely to toss food. Younger households were less likely to use up most of their items in their refrigerators while homes occupied by people aged 65 and older were more likely to avoid waste.

According to the Food and Agriculture Organization in the United States, about one-third of the food we produce worldwide (1.3 billion tons annually) goes to waste. Imagine coming home with three bags of groceries, and then throwing one of them straight into the trash.

Financially speaking, this translates to a $680 billion burden in industrialized countries and $310 billion in developing countries.

What’s really tragic is that we have massive food waste while a significant fraction of the population lives with food deficiencies. Around 40 million Americans struggle with food, and 2.9 million households with children are food insecure at some time each year.

The Ohio State researchers say that food waste at home — as opposed to restaurants, grocery stores, and farms — is the most significant source, being responsible for 43% of all food waste. At the same time, homes also represent the most challenging environment to drive change.

“Our results suggest that strategies to reduce food waste in the U.S. should include limiting and standardizing the number of phrases used on date labels, and education campaigns to help consumers better understand the physical signs of food safety and quality,” said Megan Davenport, who led the study as a graduate student.

There are some things that each of us can do to reduce our food waste footprint. Some simple tips include:

• Organize your fridge. “First in first out” is a good rule of thumb, because foods often get forgotten at the back of the fridge.
• Use the freezer. Almost all leftovers, both from cooked food or other ingredients (bread, fruits, etc) can be frozen and reheated at a later time. This not only prevents food waste, but can give you a free meal later.
• Get creative when cooking. Maybe you bought some yogurt for a cake, and there’s a bit left over. You can either freeze that or use it in another recipe, like a salad or another cake.
• Don’t over-buy. Sometimes (especially when we’re hungry) we tend to buy out at the supermarket, and oftentimes, we buy more than we need. Keep a mental note of what’s left in the fridge and buy foods that complement those — use everything!

The USDA also has a really useful app, called FoodKeeper. The app can tell you how to store and cook over 400 foods and even sends alerts when food in your refrigerator is approaching the end of its recommended storage life.