As students at Portland’s Longfellow Elementary School ate lunch, Levi Franck described his school meal in a way you might not expect from a fifth-grader.

“I like how every time I eat something there’s a vegetable to eat,” said the 10-year-old, finishing up the day’s meal of chicken, corn and beans with a choice of carrots, cucumbers, a banana or corn bread.

Asked to clarify that he does, in fact, enjoy eating his vegetables, Franck nodded, yes. “Green beans, corn,” he said, describing all the school food as “pretty good.”

Franck’s positive review would no doubt please federal officials who are overseeing the most significant nutritional changes to the National School Lunch Program in nearly two decades. New guidelines that took effect last fall under the 2010 Healthy, Hunger-Free Kids Act limit calories and salt, add more whole grains and require daily servings of fruits and vegetables.

As kids return to class this fall, they’ve had a year to adapt to the healthier meals.

“For the most part, it went well, considering the magnitude of the change,” said Kevin Concannon, the U.S. Department of Agriculture’s under secretary for food, nutrition and consumer services.

The new guidelines do away with the familiar food pyramid for healthy eating in favor of the USDA’s revamped “My Plate” model, which encourages Americans to load up at least half of their plates with fruits and vegetables.

Students mostly adjusted to the requirement to pick a fruit or vegetable in the lunch line, but some older kids balked at the smaller portion sizes for grains and proteins, said Ron Adams, director of food services for the Portland school district.

“For 30 years we’ve been filling them up on grains and protein and now all of a sudden we’re trying to fill them up on broccoli,” he said. “We got a little pushback on that one.”

In Portland middle and high schools, student participation in the lunch program dropped 10-15 percent after the changes. But systemwide in grades K-12, participation dropped just 2 percent and the numbers improved over the second half of the year, Adams said.

“You kind of see that curve, everybody reacts badly and drops out and then by the end of the year they’re back,” he said.

In December 2012, the USDA relaxed the new limit of two ounces per day of grains and meats, while sticking to the age-adjusted calorie limits. Those updates addressed most of the complaints schools voiced about the new requirements, said Concannon, who formerly headed several state agencies in Maine, including health and human services departments.

Nationally, a small number of schools dropped out of the federally subsidized program, which reimburses schools for meals and provides reduced-cost and free lunches to children. Some cafeterias lost money after students shied away from the healthier options in the lunch line.

Schools have the option to participate in the school lunch program, but miss out on the federal reimbursements and access to lower-priced foods if they go it alone.

Concannon said the overwhelming majority of schools have stuck with the program. Of the 100,000 schools nationally that participate, fewer than 250 dropped out as a result of the new guidelines, he said.

No Maine schools have dropped out of the program due to the new rules, according to the state education department.

Schools must not only meet the mandated nutritional requirements but also keep a lid on costs while providing fresher, healthier ingredients. Adams said he spends just $1.25 for each lunch tray.

He’s also incorporating more local foods into school meals, with a push from Portland Mayor Michael Brennan. Every Thursday, Portland schools feature local foods, such as corn on the cob from Jordan Farm in Cape Elizabeth, beef from Maine Grind in Guilford, and carrots processed at Northern Girl in Van Buren.

Last year, Portland schools purchased 64,000 pounds of local foods, more than twice that of the much larger Boston school district, said Adams, sitting in his office at the district’s new 20,000-square-foot central kitchen on Waldron Way.

With the new facility, school meals are made from scratch, portioned onto trays, topped with plastic, trucked to each school and reheated on site. During the prior three decades, school meals sat in warmers for hours at a time, Adams said.

“The kids have been really excited about having hot food, imagine that,” he said. “What a concept, they like hot food hot.”

Fifth-grader Levi Franck confirmed as much, noting that the cheese on the school pizza — now made with reduced-fat cheese and whole-grain dough — melts much better. Several other students concurred, included blond-haired fellow fifth-grader Clayton Meyer.

“It doesn’t taste like cardboard,” he said.