Identification of Children's BMI Trajectories and Prediction from Weight Gain in Infancy.

OBJECTIVE: The goal of this study was to identify patterns of BMI changes across childhood (ages 24 months to 13 years) and to assess whether demographic characteristics, birth weight, and percent infant weight gain from birth to 15 months predicted BMI patterns.
METHODS: Eleven waves of data from the Study of Early Child Care and Youth Development were used. Trained technicians assessed children's weight at birth and 10 times from 15 months to eighth grade (N = 1364). Latent growth modeling was used to estimate BMI change trajectories, and logistic regression was used to predict membership in trajectory classes.
RESULTS: Children in the high-rising and low-to-high BMI patterns had the highest BMI of all trajectory groups during middle childhood. Birth weight and infant weight gain were stronger predictors of trajectory membership than gender or race/ethnicity. Infant weight gain predicted high-rising membership over and above the effect of birth weight. African American children had lower birth weight, faster infant weight increase, and higher odds of being in one of the rising trajectories. Risk algorithms are provided.
CONCLUSIONS: Clinicians should monitor weight gain during infancy independent of birth weight. Researchers should continue investigating the lasting physiological effects of early rapid weight gain in infancy.