CHICAGO — Soy protein tortillas. Chipotle-lime sunflower seeds. Garbanzo bean dip.

These healthful foods were among the options for public school menus presented last week at the national School Nutrition Association Conference at McCormick Place.

With schools emerging as a front line against childhood obesity, more than 7,500 food service directors, cafeteria managers and so-called "lunch ladies" attended the conference, taste-testing recipes that could end up in cafeterias by the fall.

Hawai'i plans to implement new lunch menus in a few years, according to director Glenna Owens of the state School Food Services Branch. The branch wants to focus on school lunch price changes for the fall before "bombarding schools with a new thing," she said.

Honolulu district supervisor Kelli Chun represented Hawai'i at the national conference. Chun, who oversees more than 40 schools, also presented creative ways to encourage children to eat healthfully.

"I did a little food magic lesson and made milk cartons levitate," said Chun, who works as a clown on weekends. "Cafe workers can do this while kids are standing in lunch lines and get them excited."

About five schools, including Lunalilo Elementary and Noelani Elementary, are interested in implementing the new lunch menus, Chun said.

An exact start date for the statewide change could not be determined, as the certification process with the U.S. Department of Agriculture may take years, Owens said.

The annual conference, held in Chicago, offered a behind-the-scenes glimpse at how school menus are shaped and how hundreds of vendors compete for lucrative school food contracts.

Though they haven't received the same negative attention as fast-food chains like McDonald's, schools across the nation serve nearly as many meals as the hamburger giant, experts say. And schools often struggle to figure out how to get kids to eat healthier.

Last year, school districts implemented new "wellness policies" mandated by the federal government to help promote nutrition and physical activity for students.

Though they follow USDA guidelines, which call for eating a variety of fruits, vegetables and whole grains, most schools determine what they'll serve in the cafeteria. In some cases, states set additional nutritional standards.

As school officials prepare for a new school year, a national report requested by Congress recommends even stricter standards to cut calories, fat and sugar in snacks and drinks sold in school vending machines, at fundraisers and in cafeterias.

"We have to target elementary schools because children cultivate eating habits at a young age and not in high school," Chun said.

"High school students would laugh if we told them to drink their milk."

Instead of soda, the report by the Institute of Medicine, part of the National Academy of Sciences, recommends water, skim or 1 percent milk, soy beverages and 100-percent fruit or vegetable juice.

For snacks? A 200-calorie portion of multigrain tortilla chips, fruit, carrot sticks and whole-grain cereals are winners.

But the Center for Consumer Freedom has said that the report could lead to a government No Child With A Fat Behind program, a riff on the No Child Left Behind education law. The growing rate of obesity is caused by lack of physical activity, not overeating, according to the group, a nonprofit coalition of restaurants, food companies and individuals.