Smiley-faced potatoes encourage children to eat their vegetables, a study has found.

The study published in the journal Nutrients found that potatoes played a significant role in school-aged children and their attitudes toward vegetables. Children between the ages of 3 and 18 should eat 2.5 to 3 cups of vegetables a day, according to the Dietary Guidelines for Americans—however, they usually only eat about 1 cup a day.

As vegetables tend to have a more bitter taste, children often prefer foods that are saltier and sweeter. Vegetables are a key part of a healthy diet, though, and hold nutrients needed to strengthen the immune system.

Their reluctance to eat vegetables can be a problem, especially in school-based settings, where it can also lead to food waste. For this reason, scientists initiated some mealtime observations to see how potatoes impacted what a child ate in a cafeteria at school.

They discovered that children ate more vegetables when they were served alongside potatoes that look like smiley faces, the study reported. This suggests that using fun shapes in food can encourage children to eat more vegetables.

“We wanted to learn more about how school meal offerings may influence kids’ eating behavior and possibly encourage greater vegetable consumption,” principal investigator Gene Ahlborn, an associate professor in the Department of Nutrition, Dietetics and Food Science at Brigham Young University said in a press release detailing the findings.

“Getting kids to eat their vegetables is always a challenge. Potatoes not only add nutrients, like potassium, directly to the plate, but they may also help encourage kids to explore other veggies that they’re served alongside and thereby help them get closer to their overall nutrition needs. [These findings] underscore the wide-reaching impacts of school menus. We want vegetables on school lunch trays to fuel kids’ bodies – not fill the trash can.”

In the study, scientists found that seasoned potatoes were less appealing to children aged between 7 to 13. They also found that when the smiley-face potatoes were served separately from vegetables, it did not encourage the children to eat them.

However, when served directly alongside the vegetables, the potato smiley faces did lead to fewer vegetables being wasted overall. The scientists believe these findings will not only help draw more children to vegetables but it could also help reduce food waste in cafeteria settings.

It has already been established in previous studies that young adults who eat potatoes are more likely to have a healthier diet and nutrient intake. The study adds to these findings and suggests that the form of potato can also have a profound impact on adolescents and younger children.