Child abuse as a predictor of gendered sexual orientation disparities in body mass index trajectories among U.S. youth from the Growing Up Today Study.

PURPOSE: This research aimed to explain sexual orientation disparities in body mass index (BMI) by examining child abuse history, weight-related behaviors, and sociodemographics.

METHODS: We used data from 7,960 females and 5,992 males from the prospective Growing Up Today Study over nine waves between 1996 (ages 12-14 years) and 2007 (ages 20-25 years). Using repeated measures of BMI (kg/m(2)) as a continuous outcome, gender-stratified latent quadratic growth models adjusted for child abuse history, weight-related behaviors, and sociodemographics. BMI at age 17 years (intercept) and 1-year change in BMI (slope) are reported.

RESULTS: Bisexual females had higher BMI at age 17 years (β = 1.59, 95% CI = 1.00-2.18) and displayed greater one-year increases in BMI (β = .09, 95% CI = .03-.14), compared with completely heterosexual females. Gay males displayed smaller 1-year increases in BMI (β = -.19, 95% CI = -.25 to -.12), compared with completely heterosexual males. No sexual orientation differences in BMI at age 17 years were observed for males, but gay males' BMI at age 25 was less than completely heterosexual males' BMI by 2 units. Among females, sexual orientation differences remained but were slightly attenuated after controlling for child abuse history, weight-related behaviors, and sociodemographics. Among males, the addition of child abuse and weight-related behaviors did not change the estimated difference in 1-year BMI increases.

CONCLUSIONS: Sexual orientation differences in BMI were partly explained by child abuse and weight-related behaviors in females. More research is needed to explore additional drivers of these disparities among both females and males.