Generating New Knowledge

At the Children’s Data Network, we use integrated administrative data to develop applied and actionable research projects, support cost-effective program evaluations, and attend to policy-relevant questions from partner agencies and other stakeholders. The project pages below provide an overview of some of our initial efforts which have focused on the health and safety of children in Los Angeles County and throughout California.

Project Title

Neighborhood Obesity Trends Among 2-5 Year Old Children Participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Los Angeles County, 2002-2011


  • May C. Wang, DrPH (Principal Investigator)
  • M. Pia Chaparro, PhD (Co-Investigator)
  • Shannon E. Whaley, PhD (Co-Investigator)


First 5 LA

Data and Research Partners

UCLA Fielding School of Public Health


Child obesity is a significant public health issue in the United States, with prevalence rates increasing with age, and averaging about 10% among the youngest (preschool‐aged, 2‐5 years) children. It is this preschool‐aged child population for which obesity prevention efforts may reap the greatest benefit. In this population, low‐income children are at especially high risk; obesity prevalence rates for low‐income preschool‐aged children increased from 13% in 1998 to 15% in 2010 in the United States, and from 15.5% in 1998 to 17.3% in 2008 in California, which is among the states reporting the highest child obesity prevalence rates.

In Los Angeles County, the most populous county in California, obesity prevalence rates among low-income preschool‐aged children may finally be leveling‐off. However, given the socioeconomic diversity of neighborhoods in Los Angeles County, it is unclear if this leveling‐off of obesity rates is experienced uniformly across neighborhoods. The aims of this study were to (1) examine neighborhood obesity trends among 2‐5 year old children who participated in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) in Los Angeles County between 2002 and 2011, and (2) determine if these trends differ between higher and lower income neighborhoods. The goal is to inform the development of effective interventions and policies for reducing child obesity.

Overview of Findings

Variable Obesity Trends. Of the 1,195 census tracts that had ≥30 children enrolled in WIC every year between 2002 and 2011, a decreasing trend in obesity prevalence was observed for 225 (19%) tracts, and an increasing trend for 356 (30%) tracts. The remaining 614 (51.4%) tracts showed a variable trend.

Connections to WIC. Comparisons of the distribution of census tracts experiencing a decreasing obesity trend since 2009 (after the introduction of the new WIC food package) were made with those that began to experience a decreasing trend before 2009, as well as those that experienced an increasing obesity trend. A total of 300 (25% of the total) census tracts showed a decrease in obesity prevalence since 2009. In comparison, 224 (19%) census tracts began to show a decrease before 2009.

Trend Variations by Sociodemographic Characteristics. When sociodemographic characteristics were examined as continuous variables, census tracts with increasing, decreasing, and variable obesity trends were observed to have similar median annual income. However, census tracts with increasing obesity trends were less educated and had a higher minority concentration when compared to census tracts showing decreasing obesity trends. When the sociodemographic variables were categorized as least disadvantaged, moderately disadvantaged, and most disadvantaged, findings indicated that residents of census tracts showing increasing obesity trends between 2002 and 2011 were less educated, poorer, and more likely to be ethnic minority.

Time Line

April 2013 August 2013


Final Report: Neighborhood Obesity Trends Among 2-5 Year Old Children Participating in WIC
The Impact of Natural Experiments on Child Obesity: A Systems Science Approach (NIH Funded Study)

Knowing is not enough; we must apply. Willing is not enough; we must do.

— Johann Wolfgang von Goethe