If you find yourself routinely throwing away groceries and leftovers the night before you check out of an Airbnb, you’re not alone: A new study values the food wasted by U.S. vacation renters at about $2 billion each year.

Based on survey results, researchers estimated that groceries, takeout and restaurant leftovers averaging $12 in value per night of short-term lodging remains uneaten. Though the analysis didn’t pinpoint how much remaining food landed in the trash, that was the most common outcome reported, along with taking food home or leaving it behind.

On average, the value of wasted food per trip amounted to about 5.1% of the nightly rental fee.

“The 5% figure is probably similar to tax rates on lodging in particular localities,” said lead author Brian Roe, professor in the Department of Agricultural, Environmental and Development Economics at The Ohio State University. “So people are basically paying an additional lodging tax through the money they spend on food that they never eat while they’re in the Airbnb.”

The findings suggested travelers would be open to information from rental hosts about composting options or places to donate uneaten food.

“There’s some interest among travelers to try to reduce their footprints, and this would be a way to do that,” Roe said.

The study was published recently in the journal Waste Management.

Data came from an online survey of 502 U.S. adults who had traveled in the past year reporting on their most recent trip using an Airbnb, VRBO or other short-term rental. Nearly all of the respondents were traveling for vacation – only 3% had been on a business trip.

Researchers made projections based on statistical analyses combined with relevant national data to calculate the annual estimate of up to $2.3 billion that short-term renters spend on food that they don’t consume before the vacation ends.

“That amount is an eye-opener,” Roe said. “And if people just realize uneaten food amounts to a 5% surcharge, either they can make sure they’re ready to transport food home if they’re in a car or can get it into the right hands for donation or composting at their rental location.”

Additional findings included:

• Travelers paid an average of $231 per night for lodging.
• Each child along for the trip was associated with a greater amount of uneaten food by the end of the stay.
• About 80% of travel groups eat at least one meal per day in a short-term rental, and 6.3% eat in for every meal.
• The $12 in wasted food per night consists of $7 in groceries and $5 in food prepared elsewhere.
• Produce and pantry staples top the list of vacation groceries most commonly unused.
• Almost half of respondents said they waste more food when they travel than they do at home, while almost 21% said their food waste at home exceeded travel food waste.

Spending on groceries alone at short-term rentals added up to an average of $34 per day – a tourism statistic not previously known, Roe said.

“There are lots of estimates of how much tourists impact local economies, but this, to my knowledge, is one of the first documentations of how much people spend per day in groceries while they’re in an Airbnb,” he said.

Results indicated 46% of hosts provided an opportunity for renters to recycle and over 20% provided instructions on what to do with uneaten food. About three-fourths of respondents said they would consider it somewhat or very helpful for hosts to offer information on how to donate unused food or compost leftover food.

“Given what we saw from consumers, there seemed to be interest in understanding if food could be donated or composted, and if so, how and where,” Roe said.

“One can imagine this as a simple addition to a host’s information booklet – probably a very doable implementation. And if that knocked that $2 billion number down to $1.5 billion, that’s half a billion dollars less each year of wasted food.”