BMI Growth Profiles Among Black Children from Immigrant and US-Born Families

A large body of research has documented racial/ethnic disparities in childhood obesity in the United States (US) but less work has sought to understand differences within racial groups. Longitudinal studies are needed to describe BMI trajectories across development, particularly for Black children from immigrant families who have been underrepresented in childhood obesity research. The current study utilizes BMI data collected longitudinally from ages 5 to 8 years and growth mixture modeling to (1) identify and visualize growth patterns among Black children from primarily Caribbean immigrant families, and (2) to compare these patterns to growth trajectories among Black children from US-born families. First, we identified four classes or trajectories of growth for Black children from immigrant families. The largest trajectory (70% of the sample) maintained non-overweight throughout the study period. A second trajectory developed overweight by age 8 (25%). Two small trajectory groups demonstrated high rates of moderate and severe obesity–i.e., specifically, a trajectory of accelerated weight gain ending in moderate/severe obesity (3%), and a trajectory of early severe obesity with BMI decreasing slightly with age (2%). We identified a very similar four class/trajectory model among Black children from US-born families, and compared the model to the one for children from immigrant families using multi-group growth mixture modeling. We found that the patterns of growth did not differ significantly between the populations, with two notable exceptions. Among Black children from immigrant families, ∼ 5% were classified into the two heavier BMI trajectories, compared to ∼ 11% of children from US-born families. Additionally, among children with an accelerated weight gain trajectory, children from immigrant families had lower BMIs on average at each time point than children from US-born families. These findings describe the multiple trajectories of weight gain among Black children from immigrant families and demonstrate that although these trajectories are largely similar to those of Black children from US-born families, the differences provide some evidence for lower obesity risk among Black children from immigrant families compared to Black children from US-born families. As this study is the first to describe BMI trajectories for Black children from immigrant families across early and middle childhood, future work is needed to replicate these results and to explore differences in heavier weight trajectories between children from immigrant and US-born families.