(PS7-A25) Understanding Obesity Among SGM-AFAB Adolescents and Young Adults: Developmental Trajectories and Risk Factors

Though obesity is prevalent across almost all demographic groups, it is particularly prevalent among sexual and gender minorities assigned female at birth (SGM-AFAB; Boehmer et al., 2007, Warren et al., 2016). It is important to understand the developmental trajectories of obesity among SGM-AFAB, to identify the appropriate ages to target with prevention efforts. We cannot assume that the same trajectories, including demographic differences, are present for SGM-AFAB as for cisgender heterosexual youth. The present study aimed to estimate the developmental trajectories of obesity among SGM-AFAB across late adolescence and young adulthood and assess for demographic differences in these developmental trajectories.

Data were drawn from FAB400, a longitudinal cohort study of SGM-AFAB youth (ages 16-20 at baseline; N= 400). Obesity was assessed in an age-appropriate manner every six months for seven waves of data for each participant in this dataset (Ng & Cunningham, 2021). Participants’ self-reported weight and height was used to calculate their Body Mass Index (BMI). Next, for data points at which participants were aged 20 or younger, according to best practices in the field of child obesity, participants’ BMI was adjusted for age and sex, using the Centers for Disease Control and Prevention BMI-for-age reference data to calculate Body Mass Index z-scores (BMIz). Demographic factors (sexual identity, gender identity, and race/ethnicity) were assessed at baseline.

To estimate the trajectories of obesity among SGM-AFAB across late adolescence and young adulthood, we used a multilevel modeling approach (MLM). The model with the best determined fit was the random intercept and random slope model, indicating that the likelihood of obesity increases linearly across ages 16-24 years and that both the intercept and slope differ across participants. Results indicated that, on average, the likelihood of being obese at age 16 was 0.01 (10% of participants) and increased by 4 percent (OR = 1.04) for every one unit (month) increase in age.

Compared to White participants, Black and Latinx participants were 25.51 and 11.61 times as likely to be obese at age 16, respectively. Regarding sexual identity, compared to gay/lesbian participants, bi + participants were 16.96 times as likely to be obese at age 16. There was no association between race or sexual identity and linear slope in obesity. There were no differences by gender identity (cisgender vs transgender vs gender non-binary) in odds of obesity at age 16. However, the linear increase in the likelihood of obesity was not as positive for transgender individuals compared to cisgender individuals (OR = 0.96).

             The results of this study aid in the understanding of the developmental trajectories of obesity. Consistent with the literature on the general population, we found a within-person association between age and likelihood of obesity, indicating that likelihood of obesity increases in a linear fashion across the ages of 16 to 24 years. In line with theorieswhich emphasize how individuals with minoritized social identities are at increased risk for physical health disorders (Eliason & Fogel, 2015), SM POC, bi + individuals are at higher risk than White and lesbian/gay individuals for obesity.