Citing widespread evidence of hunger on college campuses, a federal report released Wednesday urged officials to work with states and colleges to help more students get access to government food assistance.

The Government Accountability Office, an investigative agency that works for Congress, found nearly 2 million students from low-income backgrounds who were potentially eligible for the federal Supplemental Nutrition Assistance Program in 2016 but did not receive the benefits.

Confusion over eligibility often hinders access, the GAO found. At nine of 14 colleges the GAO contacted, some officials and students said they were unfamiliar with the program or didn’t fully understand its rules. The report recommended the Agriculture Department’s Food and Nutrition Service clarify on its website who is eligible and share more information on state efforts to promote the program among college students.

Federal law bars many full-time college students from participating in the nutrition program but allows exceptions. Among them, according to the report, are parents with young children, participants in federal work-study programs, recipients of Temporary Assistance for Needy Families and students who work at least 20 hours a week.

The GAO reviewed more than two dozen studies of student access to food and found food insecurity rates ranged from 9 percent to more than 50 percent. The data suggested the problem was more prevalent among community college students than those at four-year colleges, the report said.

Federal student aid — which is separate from the nutrition program — often fails to cover college expenses. The maximum Pell Grant this year is $6,095, but that is far less than the typical bill from a four-year college. The average charge for tuition, fees, room and board at a public four-year college is $21,370, according to the College Board.

As a result, many students must obtain grants from colleges, take out loans and find jobs to pay their bills. Even so, many worry about where their next meal will come from.

Hundreds of colleges have set up campus food pantries and taken other steps to combat hunger. George Washington University in 2016 established a distribution point for students to obtain free food, seven days a week, no questions asked.

The GAO found more than 650 colleges nationwide had pantries as of September or were developing them.

“Demand for the food pantry has increased tenfold in the last two years,” one college official told the GAO. “We have far more demand than supply. We’re trying to get additional delivery days for produce because as soon as produce is stocked it’s gone the same day. The same is true for protein, especially frozen chicken.”

The GAO spoke with officials at 14 schools, from Cuyahoga Community College in Ohio to the University of California at Berkeley. On several of those campuses, students shared their worries about food.

“I don’t tell my family that I’m struggling with food because everyone I know is struggling with money — I don’t want to stress them out,” one student said.

Another said: “I did not have much money when I started school, and immediately had to choose whether to buy food or a $200 book for class. I chose to buy the book.”

One expert on campus hunger hailed the report.

“This is an important moment for those of us who have been hearing about hunger on campus from students, administrators and faculty for a very long time,” said Sara Goldrick-Rab, a professor of higher education policy and sociology at Temple University. “This is the first federal report to acknowledge that campus food insecurity is a serious challenge, and it’s important that this message is being heard at the federal level.”

The Agriculture Department’s press office did not immediately respond to an emailed request for comment. The report said Food and Nutrition Service officials told GAO in December that they “partially concur” with the recommendations and plan to review the agency’s guidance on the issue “to determine if any improvements are warranted.”