Gay youths are more likely to purge or take laxatives, use diet pills, or fast to lose weight than their straight peers, according to new research from the University of British Columbia which analyzed data from surveys of youths ages 12 to 18 that were administered every two years at public high schools in Massachusetts between 1999 and 2013. Students were asked about their sexual orientation, whether they used diet pills, refrained from eating for 24 hours or more, or vomited or took laxatives to lose or keep from gaining weight in the last month. 

Disordered eating behaviors are declining for straight teens, but for lesbian and bisexual girls, the gap appears to be widening. Disordered eating behaviors refer to unhealthy eating habits that have not been diagnosed by a physician as an eating disorder. 

"While it's promising to see improvements in the rate of disordered eating behaviors among heterosexual youth, we cannot say there has been any definite reduction of these behaviors for sexual minority youth," said Ryan Watson, the study's lead author and a postdoctoral research fellow in UBC's Stigma and Resilience Among Vulnerable Youth Centre in the School of Nursing. "For lesbian and bisexual girls, the rate of disordered eating behaviours is actually increasing, which is alarming."

The researchers found that, in 2013, lesbians were twice as likely to report purging and fasting for weight control than they were in 1999. For bisexual girls, the prevalence of purging (33 per cent) was higher than for lesbians (22 percent) in 1999, but it stayed nearly the same in 2013 (30 per cent), while it increased for lesbian girls (36 percent). In contrast, among heterosexual girls, eight percent reported purging in 1999, which declined to five percent by 2013. Heterosexual boys had the lowest rates of these behaviors, and they declined even further over the years.