Label date “bias” leads to unnecessary food loss, study flags

04 Jul 2023 --- Up to half of US consumers could be throwing away perfectly good milk based on the best-before-date label alone, without paying attention to the words accompanying it, according to a new study. Milk represents 12% of all food waste by US consumers.

The researchers, from the Ohio State University, used eye-tracking technology to monitor how participants looked at different date labels on milk cartons, such as “sell by,” “best if used by,” or “use by.”

Finding that 50% of the participants decided to discard milk based on the date only, regardless of the label phrasing or the actual quality of the milk.

“We asked them if they intended to discard it and if they said yes, it didn’t matter which phrase was there,” says Brian Roe, senior study author and professor of agricultural, environment and development economics at the Ohio State University.

“As soon as we changed the printed date, that was a huge mover of whether or not they would discard. So we documented both where their eyes were and what they said was going to happen. And in both cases, it’s all about the date, and the phrase is second fiddle.”

Label learning
Roe highlights that consumers need more education and guidance on how to interpret date labels and reduce food waste.

“If you’re going to have an education campaign, it helps to have a set of phrases out there that people can cling to – but in the end, so few actually look at the phrase. They look at the date.” 

“The date signifies a point after which you can expect the quality to degrade. If you can get firms to push that date further out, then people are going to be willing to use the milk, or whatever it is, for a few more days and waste a lot less food.”

Milk represents 12% of all food waste by US consumers.Study methodology
Researchers of the study – published in Waste Management – gave 68 study participants two sets of milk samples. 

The first set had images of eight partly empty containers with dates and phrases, such as “sell by” or “best if used by” and two real samples of fresh or sour milk. The second set had images of eight containers without any labels and two real samples of good or bad milk.

Researchers used numbers to link the real samples to the images of the containers.

They tracked the participants’ eye movements and found that they focused more on the date than the label phrase. They looked at the date sooner, more often and longer than the phrase.

The phrase did not matter much to the participants. They did not look at it for long, no matter what it said, according to the researchers.

Though the milk quality affected participants’ intent to throw it away, according to the researchers – souring milk having about a third higher discard probability than fresher milk – the quality factor did not influence what participants spent the most time looking at on the label.

“The milk was intentionally made to smell a bit sour, and it didn’t fundamentally change the fact that people really focus on the date,” Roe notes.

Minimizing food waste
Although the findings align with previous studies, Roe highlights that the researchers “were a bit surprised that over half of the viewing sessions featured no attention on the phrase whatsoever.” 

“The date is more salient – you have to reference it against the calendar. It’s more actionable than the phrase is.”

“For policy reasons, it’s still important to narrow the phrases down to two choices. But that’s only the beginning – there needs to be a broader conversation about pushing those date horizons back to help minimize food waste,” he concludes.

The study’s publication comes as this week’s European Commission leaked plans to curb food waste appear to be less ambitious than initially thought and fail to reach UN goals. 

Leaked draft legislation signals the EU is considering setting a binding target to reduce food loss by 30% by the decade’s end, compared with the 50% expected by NGOs and UN Development Goals.

By Marc Cervera