Associations between sex differences, eating disorder behaviors, physical and mental health, and self-harm among Chinese adolescents

BACKGROUND AND AIM: Eating Disorders (ED) result in impaired well-being, but there exist an insufficient number of studies that have focused on the influence of sex and sexual orientation disparities within ED behaviors. Thus, we aimed to investigate ED behaviors among male and female adolescents with different sexual orientations in a school sample to understand prevalence and correlates of different ED behaviors. METHOD: Data was analysed from 11,440 Chinese school adolescents with a mean age of 14.74 years (SD = 1.46). Reported data was gathered on sociodemographic information including sexual orientation, ED behaviors, health factors (reported health, cognitive function), mental health factors (depression, anxiety, suicidal ideation, non-suicidal self-injurious behavior), and social functioning (school bully victimization, and school bully perpetration). Logistic regression models were used to estimate the associations with ED behaviors, using the heterosexual orientation as the reference group as they are the majority. RESULTS: Compared to female adolescents, male adolescents reported lower anxiety symptoms (t = − 12.39, p < 0.001, Cohen’s d = − 0.233), were more likely to be the perpetrator of school bullying (χ(2) = 190.61, p < 0.001, φ = 0.129), and reported a lower likelihood of taking dietary restriction (χ(2) = 290.08, p < 0.001, φ = 0.160). Overall, the prevalence of dietary restriction presented sex disparities. Adolescents who reported no sexual attraction were less likely to engage in ED behaviors. Using heterosexual orientation as the reference group, the group who reported no sexual attraction was associated with lower risk in dietary restriction and purging in both male and female adolescents. Using the heterosexual orientation as the reference group, female sexual minority groups were at high risk of ED behaviors, with bisexual orientation and gay/lesbian orientation having a higher likelihood of engaging in objective binge eating. CONCLUSIONS: The results revealed significant sex and sexual orientation differences of ED behaviors. The study suggests that adolescents is a period of sexuality development and could be critical for understanding adolescents’ eating behaviors. It is important to guide adolescents to healthy eating during their development and considerations should be made by clinicians when creating interventions for ED behaviors among the different sex and sexual orientation groups. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40337-023-00754-7.