At a School Nutrition Association conference in Denver this past July, Halls demonstrated some healthy recipes for curious cafeteria managers, joining White House Chef Sam Kass to prepare a veggie wrap using a whole-wheat tortilla.

Halls’ main mission, though, was not pushing new recipes, but teaching cafeteria managers the marketing strategies used to great success by private-sector restaurants and food producers.

The first step, cafeteria workers were told, is to stop thinking of lunchtime as a break from academics, but as a crucial part of a child’s school day.

“Your job is not to serve kids food. Your job is to motivate kids to be adventurous and healthy eaters,” said Barb Mechura, head of nutrition services at schools in Hopkins, Minn. Her school district recruited parent volunteers to be elementary school “food coaches,” touring cafeterias and handing out samples of fruits and vegetables. The food coaches also would demonstrate eating them.

Food coaching might seem silly, but kids who have eaten chicken only as nuggets or patties might not know how to eat bone-in chicken—and need to see how a grown-up eats it before trying it themselves.

As the kids graduate to middle and high schools, and grown-ups in the cafeteria aren’t as welcome, schools can tap student ambassadors to be food coaches, perhaps asking the baseball team or a popular student athlete to dish out veggies. Or, high school seniors might give underclassmen samples of a new vegetable coming to the cafeteria.

School cafeterias also are using cutting-edge market research. They’re filming what kids eat, test-marketing new products before they go on the line, and doing menu surveys to find out exactly what students think about a dish’s taste, appearance, and temperature.

A Colorado State University professor studied the dining habits of kids in Loveland, Colo., with an eye toward measuring ways to get them to choose healthier foods. Leslie Cunningham-Sabo, who photographed “before” and “after” pictures of kids’ lunch trays, found that kids eat more fruits and vegetables if they have lunch after recess, instead of before recess. She found that corn consumption went up when generic “corn” labels were replaced with colorful cards describing the vegetable as “mellow yellow corn.”

Another trick—just like supermarkets place impulse buys, such as candy and chewing gum, by the checkout—is for lunch lines to place easy-to-grab fruits and veggies by their cash registers. Cunningham-Sabo’s study saw cafeterias double their sales of fresh fruit when they were placed in colorful bowls in a convenient place.

The marketing doesn’t stop at the cafeteria doors. Lassen View Elementary School in Redding, Calif., got children to eat more fruits and vegetables when cafeteria manager Kathie Sardeson started a recess snack cart bringing the foods straight to the playground for kids to munch on.

Her school also bought an iPad 2 to raffle away to students who entered by choosing a healthy breakfast yogurt parfait and turning in tickets attached to the bottom. She tempted kids to try unusual flavors by giving out “Fear Factor Smoothies,” including unexpected ingredients such as spinach. Sardeson said schools can be persuaded to invest more in nutrition promotions, because the payoff is better students.