(Reuters Health) – Transgender and non-transgender lesbian, gay and bisexual college students seem to be at the highest risk for eating disorders, according to a new study.

As reported April 28 in the Journal of Adolescent Health, the study involved students at 223 U.S. universities - including more than 200,000 heterosexuals, 5,000 who are “unsure,” 15,000 who are gay, lesbian or bisexual and 479 who are transgender.

This study is the first to include enough transgender people to make meaningful comparisons to other gender identities, said Alexis E. Duncan, the study’s senior author from George Warren Brown School of Social Work at Washington University in St. Louis.

“We found that broadly speaking, cisgender" - that is, not transgender - "heterosexual men had the lowest rates, followed by cisgender sexual minority women, cisgender heterosexual women, cisgender unsure and sexual minority men and women, and that trans people had the highest rates,” she said in an email to Reuters Health.

The students self-reported their mental health, substance use, sexual behavior, and nutrition history on questionnaires distributed between 2008 and 2011.

They reported whether or not they had been diagnosed or treated by a professional for anorexia or bulimia within the previous year, and if they had vomited, taken laxatives or diet pills over the past month.

The researchers compared various gender identity and sexual orientation groups with cisgender heterosexual women, who are usually the focus of eating disorder literature.

About 1.5% of the students said they were diagnosed with an eating disorder during the previous year. Almost 3% had vomited or used laxatives and more than 3% had used diet pills during the previous month.

These reports were all most common among transgender students and least common among cisgender heterosexual male students, the researchers found.

Compared to cisgender heterosexual women, cisgender lesbian or bisexual women were less likely to report a past-year eating disorder. But cisgender unsure women and men and cisgender gay or bisexual men were more likely to report a diagnosis.

Transgender students were more than four times as likely to report an eating disorder diagnosis as cisgender heterosexual women.

Transgender students were also twice as likely to report using diet pills and more than twice as likely to report vomiting or using laxatives during the previous month.

The new study mirrors many of the findings from past research but includes more participants and compares transgender and cisgender people, said Monica Algars of Abo Akademi University in Turku, Finland.

In a previous study, Algars found that transgender people may strive for thinness as an attempt to suppress features of their birth gender, or accentuate features of their self-identified gender, she told Reuters Health by email.

“Other potential explanations include minority stress due to stigma and discrimination,” said Algars, who wasn’t part of the new study.

She cautioned that eating disorders were evaluated in this study based on only a handful of questions. Also, it’s possible the increased diagnoses among transgender people result from more contact with mental health professionals.

It is important to recognize how eating disorders can be related to gender dysphoria and body dissatisfaction among transgender people, Algars said.

“On a more positive note, many transgender people report that gender reassignment treatment can alleviate body dissatisfaction and eating (disorders),” she said.

SOURCE: http://bit.ly/1bBapM9

J Adolesc Health 2015.

(By Kathryn Doyle)