Oliver Jane, 15, said that when she had meal debt at Shawnee Heights High School in Tecumseh, Kan., she was told to return her tray of hot food and was given a cold sandwich instead.

“If you didn’t eat the lunch, they were just going to throw it away,” she said. “It seems unfair to me to expect a bunch of kids to be responsible for putting money in their lunch accounts when they don’t even handle their own funds.”

Marty Stessman, superintendent of the Shawnee Heights Unified School District, said that younger children were allowed to take a limited number of meals despite debt, but that high school students were not.

“Notices are sent home automatically when they go below $5, so it shouldn’t be a surprise,” Dr. Stessman said. “They should know before they get to the cashier.”

The problem of meal debt is not new, but the issue has received more attention recently because the Department of Agriculture, which oversees school lunch programs, imposed a July 1 deadline for states to establish policies on how to treat children who cannot pay for food.

“It has been a longstanding issue in schools, one that’s gone on for decades,” said Kevin W. Concannon, who was the department’s under secretary for food, nutrition and consumer services in the Obama administration.

After a 2010 overhaul of school nutrition standards, the department heard from schools and advocacy groups about the burden of lunch debt and the shaming practices that often result. Last summer, the Agriculture Department concluded that meal debt should be managed locally, but required states to formalize their debt policies.