Age at Onset of Obesity among U.S. Adolescents: Findings from the National Longitudinal Study of Adolescent Health

Aiko Hattori, University of North Carolina at Chapel Hill
Chirayath Suchindran, University of North Carolina at Chapel Hill

Adolescence obesity is a growing public health concern in the United States. We use the National Longitudinal Study of Adolescent Health (Add Health) data to examine differentials in age at onset of obesity. Use of Add Health poses methodological challenges. Obesity status was assessed only at four discrete time points; data gathering involves informative sampling and clustered sampling. We also postulate that an unknown proportion of the population may be long-term survivors of obesity or not at risk for obesity. We use non-parametric maximum likelihood procedures to estimate the proportion obese by age. We also use accelerated failure time models to estimate the distribution of time to obesity in the presence of long-term survivors. Non-Whites and males are more likely to become obese earlier than non-Hispanic Whites and females, respectively, when at risk for obesity. However, non-Hispanic Whites and males have lower risk for obesity than non-Whites and females, respectively.