The Effect of Birth Weight on Childhood Obesity

Furrina F. Lee, University at Albany, State University of New York (SUNY)
Timothy B. Gage, University at Albany, State University of New York (SUNY)
Erin O'Neill, University at Albany, State University of New York (SUNY)
Xiaoyuan Tan, University at Albany, State University of New York (SUNY)
A DiRienzo, University at Albany, State University of New York (SUNY)

Conventional linear analyses indicate that higher birth weight predicts subsequent obesity (a risk factor for cardiovascular diseases). Paradoxically, a reduced risk of cardiovascular diseases is associated with higher birth weight. This study explores the association between birth weight and BMI (a measurement of obesity) at age seven by applying Covariate Density Defined mixture of linear regressions (CDDmlr) to the 1958 British birth cohort. Our analysis identifies two latent subpopulations (“normal” and “compromised” fetal development) and accounts for significant unmeasured heterogeneity in childhood BMI. Overall, 87-88% of the births are “normal” and their BMIs increase with birth weight. The remaining “compromised” births, though significantly smaller at birth, have higher BMIs and account for the majority of obese at age seven, compared to “normal” births. By demonstrating the association between faster postnatal growth rates with “compromised” births, our analysis offers a rational explanation for the birth weight and obesity paradox.