The longitudinal relationship between sleep duration and body mass index in children: a growth mixture modeling approach.

OBJECTIVE A growing number of studies indicate that shorter sleep durations could contribute to obesity in children. The objective of this article was to further examine the longitudinal relationship between sleep duration and body mass index (BMI) in children by using a growth mixture modeling approach. METHOD This article used prospective data from the Longitudinal Study of Australian Children. Participants included 1079 children aged 4 to 5 years (2004) followed up until age 10 to 11 years (2010). Growth mixture modeling was performed to examine the longitudinal association between sleep duration and body mass index within distinct body mass index trajectories. RESULTS The results indicated 3 distinct body mass index trajectories: healthy weight, early onset obesity, and later onset obesity. Longitudinal inverse associations were evident between sleep duration and body mass index in the Early Onset Trajectory. There were some associations between sleep duration and body mass index in the other trajectories. CONCLUSIONS This article provides further insight into the longitudinal relationship between sleep duration and body mass index in children. In particular, the results indicate that shorter sleep durations are primarily associated with body mass index in children with early onset obesity.