It’s national school breakfast week, and federal officials say that the number of K-12 students who are eating the first meal of the day at school is on the rise.

Between 2009 and 2013, the number of students served free breakfast in the nation’s public schools jumped by about 2 million, with the District of Columbia leading the country in terms of having the biggest percentage increase in participation compared to all 50 states.

Nationally, the number of K-12 students eating free breakfast at school grew by an average of 18.9 percent in the past five years, from 11.1 million in 2009 to 13.2 million in 2013.

But in the District, the rate ballooned by 72 percent over those same years, from 20,431 participating students to 35,038.

The District also leads the country in the percentage of hungry children. In 2011, New Mexico and the District had the highest rates of children in households without a consistent food supply — about 30 percent, according to Feeding America, a national nonprofit. That same year, 20 percent or more of the child population in 36 other states lived in households where they did not get enough to eat, the group said.

Maryland also outpaced the national rate, feeding 154,317 students in 2009 to 211,651 students in 2013, or a 37.2 percent increase. Virginia growth rate was below the national average at 16.3 percent; it fed 234,396 students in 2009 and 272,501 in 2013.

“The champions of school breakfast are not just the school nutrition directors,” said Kevin Concannon, USDA’s undersecretary for food, nutrition and consumer services. “It’s principals and superintendents. They see the results. They see kids who aren’t falling asleep, who are doing better in classes.”

Several factors have propelled the jump in the number of students eating free breakfast at school, Concannon said.

Program officials saw a spike in the years following the 2008 recession, he said. School meals started featuring more fresh fruits and vegetables as a result of the 2010 Healthy Hunger-Free Kids Act. And an increasing number of schools began serving breakfast in the classroom instead of the cafeteria, a simple shift that drove up participation, Concannon said.

In the rush before the first bell of the school day, it’s difficult to get students to make a detour and go to a cafeteria for breakfast, he said. Bringing breakfast into the classroom makes it much more convenient, especially for young children. “It doesn’t send the children trundling down the hall to a central location,” he said. “It brings breakfast to them.”

On a recent visit to an Anne Arundel County school, Concannon saw first-hand why educators are serving breakfast in the classroom. “The students came in, were handed a Ziplock bag and they could take the foods they wanted and sat at their desks,” he said. “It was all done quietly with no great fuss.”