Researchers said those students reporting few nights of adequate sleep had a mean grade point average of 3.08 compared to 3.27 for those who reported no sleep deficiencies.
"The more days students get adequate sleep, the better GPAs they attain," study leader Dr. Ed Ehlinger of the University of Michigan's Boynton Health Service said in a statement. "There is a direct link between the two."
Other factors tied to lower GPAs were excessive television or computer screen time, gambling, use of alcohol and tobacco and stress.
In the study, 69.9 percent of college students reported they were stressed and of those, 32.9 percent said stress hurt them academically. The mean GPA for stressed students was 3.12 compared to 3.23 for students who did not see themselves as stressed.
"Our study shows that there is a direct link between college students' health and their academic achievement," Ehlinger said. "This is the first time that anything like this has been published where grade point average is linked to all these behaviors."
The study was based on a 2007 survey of 9,931 randomly selected two- and four-year college students.