At the turn of the new year, the Lee County, Fla., public schools were losing about $2,000 a week on school lunches. Then came the cheese sandwiches.

When classes resumed Jan. 3 after the winter break, the district – the 40th-largest in the United States, with about 80,000 pupils – had a problem. Up to 1,100 pupils weren’t paying for their meals, school officials say.

Because the National School Lunch Program, or NSLP, requires participating schools to provide nourishing meals for all pupils, what do school administrators do if a pupil shows up in the lunchroom with no cash and with no money left in his or her electronic meal account?

Most raise their prices for kids who can pay, according to research by the nonprofit School Nutrition Association, which found that nearly 60 percent of public school districts raised lunch prices in 2009, the last full year for which national figures were available.

The Agriculture Department – which administers the NSLP – says roughly two-thirds of the 5 billion meals served under the program each year are free or are sold at a reduced price. That means you can’t keep raising meal prices indefinitely, because the burden is disproportionally borne by the pupils […]