De La Paz said the city's price increase is an attempt to "be comparable to other districts" in Maryland, because "the families in Baltimore who can afford [the increase] very much look like the families from around the rest of the state."
One city parent called the increase "aggressive" for middle-class families.
"There are many families who qualify as middle income and are ineligible for free and reduced-price lunch whose weekly family finances will be impacted by this increased cost, especially if paying for daily lunches for multiple children," said Melanie Hood-Wilson, the parent of a city student who buys lunch a few times a month.
"As a city whose leadership continues to insist that it desires to increase its tax base by increasing its middle-income population, such an aggressive increase feels like one more way in which financial burdens are made quite heavy for middle-income families."
Advocates praised the city's efforts to serve more students at the same time there's a mandate to provide them with better meals.
Anne Sheridan, executive director of the Governor's Office for Children, called the city's plan to provide low-income children with free meals "a big leap of faith that districts are starting to take, and we embrace that leap."
"I see this as part of the school system looking very carefully at all the ways that their kids can have access to adequate nutrition," she said.
By eliminating the 40 cents for its reduced-price students, the system will lose about $160,000, which De La Paz said would be made up through federal reimbursements if the district can raise its participation rate among those students from 52 percent to 60 percent.
"It's a risk we're taking, because more than 300 more kids would eat in the cafeteria every day," he said. "And through the reimbursements, we should at least break even."
Last school year, 84 percent of the city's roughly 85,000 students were eligible for the free and reduced-price meal program, while 13,500 received no subsidy if they paid for lunch.
The city offers free breakfast to every student in the system.
Students become eligible for discounted lunches according to household income levels set by the federal government; for example, a family of four with an annual household income of $43,568 would qualify this year.
According to the most recent U.S. Census Bureau statistics, the median household income in Baltimore was $40,100 between 2007 and 2011.
Across the state, full-price lunches range from $2.50 for elementary school students in Montgomery County to $4 for some high school students in Howard County.
Unlike the city's new structure, most school districts put the costs for elementary, middle and high schools on tiers. For example, in Baltimore County, lunch costs $2.90 for elementary school students, and $3 for middle and high school students.
But a review of lunch prices for large, urban school districts shows that Baltimore's new $3 price is higher.
In New York City — which also eliminated its 25-cent reduced-price fee for students — lunch will cost $1.75 this year, an increase from $1.50. It was the first increase in 10 years.
In Washington, high school students pay $2.50. In Los Angeles, the most students pay is $2. Baltimore's new lunch price is also higher than those in Chicago, Miami, Boston and Denver.
In Maryland districts with a comparable student population, the city's lunch prices also exceed those of Prince George's County, where the highest price is $2.85.
De La Paz said he believes that the other districts' "lower prices exist because of lower quality and smaller portions."