Associations of community, family and early individual factors with body mass index trajectories among children aged 1-18：a longitudinal study in China

Recently born children are increasing in height and weight, but no studies have analyzed changes in BMI trajectories and the heterogeneity in China. We aimed to examine the developmental trajectories of BMI among Chinese children and the potential determinants including early individual factors, family and community factors. Data came from the China Family Panel Studies (CFPS 2010, 2012, 2014, 2016, and 2018), and group-based trajectory modeling (GBTM) was employed to identify BMI trajectories from 1 to 18 years. Multivariate logistic regression was conducted to determine the association between early individual, family, community factors and child BMI trajectory. We identified three distinct BMI trajectories among boys and girls: low-increasing, medium-increasing, and high-increasing, and found that early individual factors, family and community factors were associated with different trajectories of BMI. There were heterogeneous BMI trajectories from children to adolescents in the recent Chinese birth cohort. Targeted interventions at early individual, family, community levels are essential.