Up to half of consumers may decide to pour perfectly good milk down the drain based solely on their glance at the date label on the carton, a new study suggests.
Researchers using eye-tracking technology found that 50% of study participants declared their intent to throw away milk based on the date stamped on the container – without ever even looking at the label phrasing in front of the date.
Each participant saw one of three phrasing options: “Sell by,” “Best if used by” or “Use by” a given date, as well as containers with no label at all.
“We asked them if they intended to discard it, and if they said yes, it didn’t matter which phrase was there,” said senior study author Brian Roe, 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 or not. 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.”
Policymakers and industry leaders are working toward settling on a universal two-phrase system – one when quality, but not safety, is the concern, and a second phrase for items where safety may be a concern, Roe said. To date, they haven’t landed on what those phrases would be.
“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,” he said. “The date signifies a point after which you can expect 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.”
The study was published recently in the journal Waste Management.
Food is wasted throughout the production process, but most of it happens at the consumer level: In the United States, consumer waste accounts for more than 48% of surplus food, according to the nonprofit ReFED.
Researchers chose milk for the study because it is widely consumed and represents about 12% of all food wasted by U.S. consumers.
Each of the 68 study participants viewed two flights of milk samples. The first featured images of eight half-empty milk containers with the same phrasing preceding a variety of dates that ranged from six days after to a week before the study day, presented alongside two physical samples each of fresh milk or poor-quality milk that the research team had allowed to go slightly sour. The second featured unlabeled milk containers alongside physical samples of good- or poor-quality milk.
In each presentation, numbering labels implied that the physical samples had been poured from corresponding containers that appeared in the images.
Data from eye-tracking technology showed that overall, participants spent more time fixing their eyes on the date compared to the phrase, looked at the date more frequently and laid their eyes on the date 44% faster than on the phrase.
When participants did glance at the phrase, the type of phrase had no significant effect on how long they fixed their eyes on the words.
Though the quality of the milk affected participants’ intent to throw it away – with 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 really fundamentally change the fact that people really focus on the date,” Roe said.
The finding aligned with previous studies led by Roe in which the intention to throw away food was driven by the label date and not the phrase.
“But we were a bit surprised that over half of the viewing sessions featured no attention on the phrase whatsoever,” he said. “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.”
This work was supported by the Van Buren Program, the Robert E. Jacobson Research and Service Fund in Agricultural Economics, the USDA National Institute of Food and Agriculture, and the Ohio State Department of Food Science and Technology FoodSURE program.
Co-authors, all from Ohio State, were Aishwarya Badiger, Talia Katz and Christopher Simons.
