"That's so gay" has been part of teenage slang for some time, but a new study has found that the phrase can have lasting effects on students who consider themselves as bisexual, gay, lesbian or transgender (LGBT).

Researchers say that the phrase, often used by young people to describe something as stupid or undesirable, while subtle, is hostile and can be harmful to sexual minorities.

Lead author Michael Woodford, an assistant professor of social work at the University of Michigan, examined the impact of hearing "That's so gay" among 114 gay, lesbian and bisexual students between the ages of 18 and 25.

The findings show that LGBT students who heard the phrase frequently were more likely to feel isolated and experience headaches, poor appetite or eating problems compared to those who didn't hear the phrase.

Researchers found that only 14 students, or 13 percent, of all participants hadn't heard "that's so gay" in the last 12 months.

"Given the nature of gay-lesbian-bisexual stigma, sexual minority students could already perceive themselves to be excluded on campus and hearing 'that's so gay' may elevate such perceptions," Woodford said in a statement. "'That's so gay' conveys that there is something wrong with being gay."

Researchers say that the stress reaction that occurs when students hear the phrase is likely to be associated with increased risk for physical health problems.

"'That's so gay' conveys that there is something wrong with being gay," Woodford said. "And, hearing such messages about one's self can cause stress, which can manifest in headaches and other health concerns."

"There is a lot of attention being given to addressing LGBT bullying on college campuses," Woodford said.

"Policies and educational programs are needed to help students, staff and faculty to understand that such language can be harmful to gay students," he added.

The study was published in the Journal of American College Health.