For most of us, a meal served at 9:38 in the morning is breakfast. For sixth-graders at Cole Middle School in Denver, it’s lunch. And, at 20 minutes long, it’s over by 10 a.m.

Cole’s mostly 11-year-old sixth-graders are about two hours into their seven-hour school day as they file into the lunchroom. Some of them had breakfast at home; others ate the school’s subsidized breakfast at 7:05.

Although most of the children chow down, some can’t summon an appetite. They pick at their food, most of which goes uneaten into the trash.

The children will have opportunities to snack during the school day and after school, but they won’t get another chance at a real meal until they’re home.

And they’re not alone. Cole’s lunch is early, but not by much compared with other middle schools in the Denver area, most of which start serving lunch between 10 a.m. and 11 a.m. because of scheduling pressures. Sixth-graders usually get the earliest slot.

But a growing number of nutritionists, educators and scholars are beginning to ask what children lose when lunch is scheduled so early, with minimal time to eat. They contend that lunch should be an opportunity for children to unwind and eat wholesome food in a leisurely fashion at an appropriate hour, rather than a scramble to scarf down a piece of pizza and get back to class.

Last year, Cole’s earliest lunch was at 9:58 a.m. Principal Nicole Veltze had to move it up, she says, when she decided to lengthen classes in math, science and literacy to 90 minutes in a push to improve test scores. At the same time, budget cuts reduced the teaching staff, leaving her with few scheduling options.

Karen Evans Stout attended and studied more than 2,000 school lunches as she researched school-lunch practices in the United States and abroad. The associate professor of education at Lehigh University in Bethlehem, Pa., says she has never encountered a lunch as early as Cole’s.

“It’s too early,” Stout says. “If school is over at 2:30, some kids are going 4 1/2 hours without food. They’re going to be very hungry at the end of the school day.

“What happens to a kid who goes home to an empty house? If dinner isn’t until 7, there’s lots of time to snack on empty calories and no adult to make sure they make good food choices.”

What’s likely to happen, says Marilyn Day, a dietitian at Children’s Hospital in Denver and director of the weight-loss and fitness program, is that the children will develop eating habits that may lead to a lifetime of obesity.

Cole is in one of Denver’s poorest neighborhoods, and has 100 or so sixth-graders. Ninety-seven percent of its children qualify for the USDA’s free or reduced-price lunch program.

“How Long Does It Take Students to Eat Lunch?” — a study published last year in the Journal of Child Nutrition & Management — concluded that students should have at least 20 minutes at the table to allow them time to eat and socialize.

Stout, who compares some school lunch programs to “feeding factories,” says children need longer unstructured breaks.

“I look at what has the strongest benefit for the kids,” Veltze says. “And the kids at Cole need to improve their academic focus more than anything else. But while we work on that, we also support their health and their emotional stability.”

The early-lunch issue tends to slip under the radar for parents of sixth-graders because the schedule was set while their children were still in elementary school. By the time most parents realize their children are eating so early, the school year is well under way and the schedule is unchangeable.