The Association between Age and Obesity Over Time

• In Event: 070 - Section on Children and Youth Paper Session. Social Contexts of Children’s Well-Being

Abstract

Background and Objectives: A decline in obesity prevalence among 2- to 5-year-old children in the United States was recently reported. This decline may be a product of changes in the population composition of children over time, or may be a consequence of changes in the strength of the association between individual- or family-level factors and childhood obesity. We used regression decomposition techniques to identify the sources of this decline.

Methods: We used data from the 2003/4 and 2011/12 National Health and Nutrition Examination Surveys restricted to 2- to 5-year-old children, and Blinder-Oaxaca regression decomposition techniques, to partition the early childhood obesity decline into changes resulting from (1) changes in the demographic, economic, and health characteristics of children over this period (i.e., changes in population composition), and (2) changes in the association between these demographic, economic, and health factors and obesity (i.e., changes in associations).

Results: The decline is attributed mainly to the weakening of the association between age and obesity between cohorts. The obesity rate declined because obesity rates for the oldest children in 2011/12 were similar to those for the youngest children in this age range, whereas in 2003/4, obesity rates for the oldest children were significantly higher than those for the youngest children.

Conclusions: If the weaker association between age and obesity we observed for this cohort of 2- to 5-year-old children in 2011/12 persists for subsequent cohorts of young children, the obesity rate for young children will remain at or near the lower rate observed in 2011/12.

Authors

• Ashley Wendell Kranjac, Rice University

• Robert L. Wagmiller, Temple University