Over one in three US university students say they don’t have enough money for food, with some even going entire days without eating because they cannot afford meals, according to a report.

The study, conducted by researchers at Temple University and the Wisconsin HOPE Lab, found 36 percent of college students said they had been food insecure over the past 30 days, meaning they were not eating healthy, nutritious food.

The report, titled Still Hungry and Homeless in College, also found that around one quarter of college students said they have skipped meals or cut the size of their portions because they couldn’t afford to eat properly.

“The bottom line is clear: Educational attainment in the United States is being hindered,” the report said. “Students’ basic needs must be secured if they are to learn at any level—elementary, secondary, or post-secondary.”

According the survey, just 48 percent of university students have not experienced food or housing insecurity or homelessness during the past year.

The study found that African-American and Native American students were much more likely than non-Hispanic white or Asian students to experience food or housing insecurity.

“It really undermines their ability to do well in school,” said Sara Goldrick-Rab, professor of higher-education policy at Temple University and the lead author of the report.

“Their grades suffer, their test scores appear to be lower, and overall, their chances of graduating are slimmer. They can barely escape their conditions of poverty long enough to complete their degrees,” she told National Public Radio (NPR).

Elsewhere in the report, nine percent of university students said they were homeless in the past year, with 3 percent of them saying they have slept in an abandoned building, vehicle or other place not meant for housing while studying their degree.

“The data show that basic needs insecurities disproportionately affect marginalized students and are associated with long work hours and higher risk of unemployment,” the report said.

“However, the level of academic effort—in and outside the classroom—is the same regardless of whether or not students are dealing with food and housing insecurity. It is therefore critically important to match their commitments with supports to ensure degree completion.”