Study: Photos in lunch trays can up kids' vegetable intake

Choosing fruit
Richfield STEM Elementary School students walk through the lunch line Wednesday, Feb. 2, 2012. The school encourages students to eat more fruits and vegetables by placing those items at the beginning of the line and the entree options at the end of the line. Also, students can go back for seconds of any of the fruits and vegetables. Richfield STEM students participated in a study that showed students will eat more fruits and vegetables if their trays have pictures of these things on them.
MPR Photo/Jennifer Simonson

Increasing the amount of vegetables children eat during lunchtime could be as simple as placing photos of vegetables in their lunch trays, according to a new study by University of Minnesota researchers.

In a study published today in the Journal of the American Medical Association, the five researchers describe a simple experiment they did at a Richfield elementary school: On a day when photos of carrots and green beans were placed in lunch trays, students took more and ate more vegetables.

The researchers — a psychologist, an economist, two nutritionists and a marketing expert — say the photos might have made students think they were supposed to take the vegetables.

"We think it just gave the kids this idea of, 'oh, that's where I put my vegetables, that must be what other people are doing," said psychology professor Traci Mann, one of the study's authors. "Somehow that suggested a norm."

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The researchers visited Richfield STEM School twice last year. A day in February was their control day, and their experiment took place during a second visit in May. The menu was identical on both days: a main dish plus a choice of green beans, carrots, orange slices and applesauce.

Cafeteria trays
Fourth-grader Piper Basso loads her lunch tray with carrots and fruit before selecting an entree Wednesday, Feb. 1, 2012 at Richfield STEM School.
MPR Photo/Jennifer Simonson

But on the second day the researchers placed photos of green beans and carrots on each cafeteria tray. The idea was to see if more students would take the vegetables on their way through the lunch line.

Not only did more students take vegetables that second day, but the total amount of vegetables consumed went up, too. Overall, students ate three times as many carrots and twice as many green beans.


But Mann said more research would be needed to support the results and to suggest ways to boost the amount of vegetables students eat. Even though students ate more carrots when photos were placed in their trays, the total vegetable intake fell short of nutrition goals set for children.

"We're not done," she said. "To me this seems like one part of a whole bunch of changes that cafeterias might want to make."

Mann said the results confirm other research on people's behaviors toward food, and points to why dropping visual hints is a favorite advertising trick. Some studies, for example, suggest that people eat more if they're given a bigger plate, or eat more vegetables if they're the first item in a buffet line. In this case, Mann said, the photo seemed to be the trigger.

The researchers said such simple changes are promising because they can make a difference without much extra cost to school districts. The photos placed in the trays were just color photocopies, which cost $3 per 100 trays. Cutting out the photos and placing them in the trays took 20 minutes per 100 trays, according to the study.

Eating lunch
Richfield STEM Elementary School students eat lunch Wednesday, Feb. 2, 2012 in the cafeteria.
MPR Photo/Jennifer Simonson

Deb LaBounty, the Richfield school district's nutrition services supervisor, said she had wanted to continue the photos in lunch trays strategy and even looked for companies that make school lunch trays that include pictures of vegetables. She didn't find any.

"I thought it was a great idea," LaBounty said.

Despite the promising results, LaBounty said placing photocopies on the trays isn't an option for the district at this point, she said.

"Not with our budget," she said. "I don't have anyone who could have that much time to be taping decals to lunch trays. We serve about 700 lunches a day at the STEM school so that would be quite an undertaking."

So instead of photocopies, LaBounty is shopping around to see if she can buy trays with pictures the next time the school district replaces its lunch trays.