Abstract

Background: Differences in the association of socioeconomic status (SES) with obesity may underlie the racial/ethnic disparities in obesity that increase dramatically across the transition to adulthood in the United States. The aim of this study was to examine racial/ethnic differences in the influence of life course SES on longitudinal obesity patterns from adolescence to adulthood.

Methods: Latent class analysis was used on a nationally representative, diverse sample of 12 940 adolescents followed into young adulthood (mean age = 21.7 years) to identify life course SES group profiles based on SES data in adolescence and young adulthood. Gender-stratified multinomial logistic regression models estimated the association of SES groups with obesity incidence and persistence versus staying non-obese.

Results: No significant interactions with race/ethnicity were observed, although racial/ethnic minorities had the highest obesity risk across SES groups. Racial/ethnic-pooled associations between disadvantaged SES exposure and higher obesity risk were strong but differed by gender. Males with a disadvantaged background who experienced early transitions into the labour force, marriage and residential independence had the highest risk of obesity incidence (relative risk ratio (RRR) = 1.64; 95% confidence interval (CI) 1.12 to 2.40), while females exposed to persistent adversity were at highest risk (RRR = 3.01, 95% CI 1.95 to 4.66). In general, SES group membership had a stronger relationship with obesity persistence than incidence.

Conclusions: The relationship between SES and obesity patterns is similar across race/ethnicity and differs by gender during the transition to adulthood. However, stronger associations with obesity persistence and enduring racial/ethnic disparities in obesity risk across SES groups suggest that these social factors play a larger role in disparities earlier in the life course.