TAMPA — There was nothing in the fridge. No pastrami, no eggs. Nothing to pack for lunch, nothing to eat that day. Nathalie Mompremier, a senior at the University of South Florida, zipped up her backpack and went to her job as a pharmacy technician. Her bag was full with the things she had spent her loan money on: textbooks, course lists, the lease to her apartment. She tried not to think about how empty her stomach felt.

Free lunch programs have long been a staple of K-12 education, with a wide-sweeping, head-nodding consensus that students can't focus on school when they haven't had enough to eat. Some schools, particularly those drawing from low-income areas, provide students with three meals a day.

But when these students get to Florida's universities — many of them taking on exorbitant costs and experiencing financial independence for the first time — all the free meals go away. And the students are still hungry.

Thousands of students across the Florida university system are experiencing "food insecurity," defined by the federal Department of Agriculture as eating not enough food or only non-nutritious food because one can't afford three meals each day.

According to data provided to the Tampa Bay Times, students struggling with food insecurity logged more than 16,000 visits in 2015 to special centers at USF, the University of Florida, Florida State University and the University of Central Florida.

USF opened its "Feed-A-Bull Food Pantry" last fall after staff counseling students on other issues realized how often they were making concerning comments about food.

"Students were reporting that a lot of times they don't have money that week for food, or they'd only be eating one meal a day because they didn't have enough to make it to the end of the semester because their loans had run out, or they didn't get their next paycheck," said Nicole Morgan, senior case manager for student outreach and support at USF.

More than 200 students visited USF's food pantry 510 times over fall and spring semester — more than staff say they expected, given the pantry was open only 32 days in the fall and 26 days in the spring. Staffed by volunteers, mainly from the campus chapter of Feeding America, the pantry allows students in need to pick up groceries. Think tuna fish, peanut butter, pasta, soup.

The pantry distributed nearly 6,000 pounds of food last school year. Almost 80 percent of visitors were undergraduate students.

"Groceries were more expensive than I thought they would be," says 22-year-old Mompremier, a first-generation college student who pays for school herself through grants, loans and minimum-wage jobs. "I was spending all my paychecks on food, and I still couldn't keep up."

Sara Goldrick-Rab, a professor of higher education policy and sociology at Temple University, said stereotypes about eating Ramen in college have masked a real hunger problem on campus and created a policy blind spot.

"Colleges do all these things to help kids at-risk for dropping out," she said. "They look at grades and missed classes, but they never ask them if they have enough food to eat or a place to sleep at night."

For some students, eating Ramen may be a choice. But for others, it's all there is, Goldrick-Rab said. And while many so-called "typical" college students have always struggled to budget for food along with textbooks, living expenses and tuition costs, a "new normal" college student is adding urgency to the issue of food insecurity on campus.

They aren't 18-year-olds whose credit card bills go to their parents, but first-generation students, working students and single parents returning to the classroom.

"In the past, these are students who would not have gone to college. But they have nowhere else to go now. There aren't jobs," said Goldrick-Rab, who has focused part of her work in South Florida. "I've watched students in community college in Miami get off the sidewalk they were sleeping on and go into class. People are going to all kinds of extremes to afford to go to school."

Goldrick-Rab is working on a proposal to expand the federal free-lunch program from K-12 to college. She estimates it would cost $1.4 billion, calling that a "drop in the bucket" compared with the overall federal higher education budget.

In the meantime, more and more universities across Florida are creating programs to feed students who would otherwise go without. The University of Florida opened its pantry last summer. Anna Prizzia, director of the UF campus food program "Field and Fork," said the school did a needs assessment and found about 10 percent of its student body experienced food insecurity during their time on campus.

"We thought it was important to take the choice between getting a good education and eating a healthy meal out of the equation for our students," she said.

In 2015, about 300 of the 4,000 colleges and universities across the United States had programs like the USF pantry to help feed students. When the University of Central Florida opened its "Knights Pantry" in 2009, it appeared to be one of the first five in the country, said student union director Rick Falco.

The pantry came about as a project in Falco's leadership class. When they first set up shop, with little more than 100 cans in a pantry, some students were skeptical that their classmates had trouble affording food.

"But when you get the first one or two students who come in and tell you their story about living out of their car, and they have to choose between buying their books and going hungry, and they want to buy their books because they want to do well in college — after that, everyone understood," Falco said.

UCF's pantry is now a freestanding facility that mimics a small store, although everything is free. Jessica Roberts, a 19-year-old junior, is the pantry's student manager. But she has also had to be a customer.

"I personally have used the pantry because I have no food. I have lots of financial responsibilities also," said Roberts, who is studying psychology. "Financial aid doesn't always disburse until the third or fourth week of school, but you've already had to pay for your classes, your books, your living expenses."

Students logged about 12,000 visits to the pantry in 2015, taking with them 27,579 pounds of food. All of the pantries, including one at Florida State University, rely on food drivers, donations and partnerships with community food banks.

One of the challenges they face is providing fresh produce and other perishable items to students. USF is in need of a working fridge. Student volunteers go to a local food bank and pick up fruit, vegetables and bread, typically from farms or left over from grocery stores and soon to expire.

Expanding access to fresh produce is number one on USF's wish list for next year, said Katie Jones, a registered dietician in the wellness education department, and one of the pantry's founders. Jones also wants to put together recipe cards to help students make the most out of what they get from the pantry. And both she and Morgan, the student outreach manager, acknowledge that spreading the word on campus needs to be a bigger piece next school year.

"I don't think as many students who need it are taking advantage of it, but it's our first year," Jones said.

The biggest hurdle they've faced? Just providing education on what food insecurity actually is, Morgan said.

"It's not normal to only eat one meal a day. It's not normal to only consume a couple crackers or an apple," she said. "And I think a lot of students don't want to use the service because 'Oh, there are people who are worse than me that need it more than I do,' and they don't actually realize that they are in that need. It's them."

Contact Lisa Gartner at lgartner@tampabay.com. Follow @lisagartner.