Specifically, they thought the fact that the apples were being served whole, rather than sliced, was doing the fruits no favor. And they were on to something.
A pilot study conducted at eight schools found that fruit consumption jumped by more than 60 percent when apples were served sliced. And a follow-up study, conducted at six other schools, not only confirmed the finding, but further strengthened it: Both overall apple consumption and the percentage of students who ate more than half of the apple that was served to them were more than 70 percent higher at schools that served sliced apples.
"It sounds simplistic, but even the simplest forms of inconvenience affect consumption," said David Just, a professor of behavioral economics at Cornell who studies consumer food choices, and one of the study's author. "Sliced apples just make a lot more sense for kids."
The hardest part is getting kids to start eating fruit, to take the first bite, and that's precisely what slicing an apple makes more appealing. A child holding a whole apple has to break the skin, eat around the core, and deal with the hassle of holding a large fruit. That barrier might seem silly or superficial, but Just says it's significant when you're missing teeth or have braces, as so many kids do.
"It's one of those circumstances where what seems like a really small inconvenience actually makes a huge difference," he said.
That realization, however new it might have been for the cafeterias where students were suddenly eating more fruit, is something that hasn't been lost on the apple industry. Amid decades of stagnant growth, apple distributors have started pushing packaged, pre-sliced apples out into the market. And it has proven to be a pretty successful strategy.
Americans ate just over 500 million fresh sliced apples in 2014, more than three times as many as they did 10 years before. The rise has been fairly consistent, as the chart below shows.
But it has also been fairly significant. The jump in fresh sliced apple consumption just so happens to coincide with an uptick in overall apple consumption, which has grown by 13 percent since 2010.
In 2013, Americans ate just under 17.5 pounds per capita, the most in almost a decade.
There is little revolutionary about serving cut-up apples. Parents, after all, have been slicing fruits and giving them to their children for forever. But there is a subtle genius in serving them commercially, packaged and ready-to-eat.
"The apple industry is a very mature industry," said Mark Seetin, who is the director of regulatory and industry affairs for the U.S. Apple Association, a non-profit that represents thousands of growers around the country. "The only way to grow is through innovation, but innovation hasn't been easy."
"This [pre-sliced apples] has offered a new pathway the industry is obviously really excited about it," he added. "Right now, pre-sliced apples make up about one out of every twenty apples sold in the country."
Why sliced apples? And why now?
The rise of sliced apples owes a great deal to a certain fast food behemoth, which began selling them a little over a decade ago.
In 2004, before any other fast food company was offering apple slices, McDonald's was adding them to its menu. At the time, the company was looking to introduce healthier options that would be attractive to children, and pre-sliced apples seemed like a good place to start.
"Sliced apples are often easier for children, especially young children, to eat," said Christina Tyler, a company spokesperson. "We simply wanted to make enjoying fruit easier and more fun for our youngest customers."
For years, the apples were offered as an optional side. But in 2012, the company began automatically serving them as part of Happy Meals. And the impact has been enormous.
While McDonald's wouldn't disclose how many apples it sold in the early years, it confirmed that it has served more than 2 billion packages since they were first offered. In 2015 alone, the company served almost 250 million packages of sliced apples, which amounts to just over 60 million apples, or more than 10 percent of all fresh sliced apples sold in the United States.
"Apples are one of the most popular side options we serve," said Tyler.
In some respects, this is a testament to the power of McDonald's, which sells so much food it has the ability to significantly alter the fate of certain foodstuff. Eggs, for instance, have benefited greatly from the company's breakfast menu. McDonald's uses more than two billion eggs per year in the United States alone, or almost 5 percent of all eggs produced in the country
"When a company as big as McDonald's helps promote something, it not only boosts sales, but also really raises public awareness," said Seetin, the industry representative.
But while McDonald's might have helped popularize the packaged apples, schools are now contributing to their sustained rise, according to Seetin. School lunches, he says, have also been "a very significant contributor to the growth."
The U.S. Department of Agriculture (USDA), which oversees the NSLP, couldn't say how many schools are serving sliced apples instead of whole ones. That decision is made by local school food authorities, not the federal government. The USDA does, however, make recommendations, among which is that fruit be served in "age-appropriate pieces."
Less food waste, more plastic waste
Despite the promise of apple slices, both for the apple industry and for child nutrition advocates, there is concern it speaks to the implacable, and sometimes harmful, desire for convenience. In this case, some fear, the demand for a more convenient fruit serving comes at the expense of the environment. Serving apples slices might decrease food waste, but when they're served in a plastic wrap, as all of the commercially available ones are, it also means a good deal more plastic waste.
McDonald's, for its part, says that it's aware of the problem, and currently working to make sure the apple packaging it uses is as sustainable as possible. "That's why our apple slice packing is recyclable," Tyler, the company spokesperson, said.
But recyclable packaging, promising as it might sound, is not the same as recycled packaging. Just because consumers can recycle a plastic wrap doesn't mean they will. And while there is no way to estimate the percentage of the packing that ends up being recycled, there's reason to believe it's probably fairly low.
Coffee pods, another product of our collective demand for convenience, after all, have become a contentious subject among environmental groups. Nespresso, which dominates the market in Europe, boasts that the vast majority of its pods are recyclable, but many still end up in the trash. The problem is so pronounced that a German city even decided to ban them earlier this year.
The future of apples slices
In some ways, the potential of sliced apples recalls the success of baby carrots, which essentially saved the carrot industry, allowing it to make use of "ugly" carrots that were unfit for sale. But then again, that set a pretty tough benchmark: Today, thirty years after they were first introduced, baby carrots account for some 70 percent of all carrot sales, and have significantly reduced waste associated with carrot production.
For sliced apples, the ceiling is probably a lot lower. Still, there is plenty of room to grow. At the moment, sliced apples only account for about 5 percent of all apple sales, a percentage that will likely only trend upwards going forward. In fact, it's a bit surprising it hasn't already.
"If anything, it's strange to me that the convenience sliced apples offer hasn't made them even more popular already, that they haven't become more of a thing," said Just, the researcher at Cornell. "If I had to guess why, I'd say it's because people are somewhat weirded out by apples that don't brown after they're sliced."
"But I'd also say that people will probably get over that soon," he added.