When it comes to health there's good news and not such good news for gay, lesbian and bisexual people compared to heterosexual people, a study by the Centers for Disease Control and Prevention indicates.

People who identify themselves as gay or bisexual tend to drink and smoke excessively and experience significant psychological stress compared to straight people, says the CDC report, the first to examine health issues in the United States population of gay or bisexual individuals on a nation-wide level.

The report, from the CDC's National Center for Health Statistics, is based on data gathered by the 2013 National Health Interview Survey of 34,557 adults.

The comprehensive health survey has been conducted annually for 57 years, but the new report is the first to "included a measure of sexual orientation, thereby enabling researchers and data users to examine how the prevalence of a wide variety of health-related behaviors," the CDC said.

Of those surveyed, 96.6 percent identified themselves as straight, 1.6 percent identified as lesbian or gay while 0.7 percent identified as bisexual.

The remaining 1.1 percent chose not to report their sexual orientation.

Although previous studies have looked at health differences based on race, ethnicity, gender and income levels, there has been less attention given to whether sexual orientation could be linked with health status, the report authors said.

Some early attempts to gather such data faced considerable resistance, says Julia Dilley, an epidemiologist in the Public Health Division of the Oregon Health Authority, who wasn't involved in the CDC survey.

"People were afraid of political backlash," she says. "They were also concerned that people wouldn't accurately report their sexual orientation."

Although the exact reasons for differences between gay and heterosexual people when it comes to health behaviors including drinking and smoking is unclear, societal stress and less access to various healthcare benefits may be among them, adds Kari Greene, another Oregon Health Authority researchers says.

"There's certainly a lot of social stress for people who are living in places where they are being treated unequally based on their sexual orientation," Greene says. "We also definitely have unequal access to healthcare benefits, for people who are living in places where healthcare benefits are not translated to same-sex spouses."

Dilley agrees, noting evidence that sexual minorities face greater health risks not related to any other characteristics such as economic status or race.

"It does seems like sexual orientation has an independent influence on disparities, and adds on top of any disparity that the person is experiencing," she says.