Key Active Projects

Project 1: Dynamics of Childhood Obesity in Pennsylvania from Community to Epigenetics

This study will extend existing data and ongoing research to understand the dynamics of childhood obesity in a large population of children living in 400 communities that vary environmental risk regulators. Using a comprehensive electronic health record based at a large primary care health system, we will obtain up to 10 repeated BMI measures on 50,000 children in order to model changes in body weight as a function of child-level factors and key features of the community. We will use both multilevel regression and system dynamics models to better understand the complex and dynamic interplay between multilevel processes. We will also conduct a nested substudy of 1100 children from a subset of 80 communities to reflect places that are both high (N=40) and low (N=40) in environmental obesogenicity. We will gather new data on diet and physical activity along with buccal swabs from which we will assess epigenetic factors in order to study how environments and behaviors lead to modulations of gene expression. This will be among the first and largest studies of how context impacts DNA methylation in loci that have been found to play a role in the appetite regulation system. We will also employ systems-dynamic models, motivated by real data, to simulate the epidemiologic consequences of policy interventions to up- or down-regulate system components identified as determinants of obesity from earlier models. This study combines novel methods with strong epidemiologic study design and a basic science component to study the complex, multilevel determinants of childhood obesity in rural areas and small towns, areas that have received insufficient attention from in research on obesity.

Project 2: Systems-Based Intervention Trial: Multi-level Obesity Prevention Study (Be More Healthy, Community for Kids)

MOPS is an intervention trial which will operate at multiple levels of the Baltimore City food system. The study aims to increase affordability, availability and consumption of healthy foods within low-income, predominantly African-American neighborhoods. We will conduct formative research at the policy, wholesaler, retailer, adult caregiver, and individual child levels, and then develop, implement, and assess a 16-month multi-level systems-based child obesity prevention strategy for African-American children.

Thirty low-income, predominantly African-American geographic zones will be identified (“healthy eating zones”). Half of these zones will be randomized to intervention, while the other half will be control. Within each intervention zone we will work with at least 5 small food stores and prepared food sources to increase access to healthy foods through wholesaler discounts and display point of purchase promotional materials. We will also provide nutrition and food preparation education targeting youth and caregivers. We will work with local policymakers to institutionalize and sustain these changes.

We will evaluate impact on psychosocial factors, stocking, prices and unit sales of promoted foods at the retailer and wholesaler levels. A sample of adult caregiver-child dyads (n=24 dyads per zone, total=720) will be surveyed to assess impact on psychosocial factors, food purchasing, food preparation methods used, dietary indicators (e.g., energy and fat intake), and obesity.

Project 3: Multilevel Systems-oriented Childhood Obesity Study in China

The study's goal is to use a systems-oriented conceptual framework, unique rich longitudinal data collected in China from large cohorts, and novel systems analysis to study the interplay, impact, and feedback loops of the built, social, economic, environmental and policy factors and their changes on individual children and their families' decisions, eating, physical activity, and adiposity outcomes. We will also study why some individuals and families may respond differently to the environments and how they may affect their environments (i.e., feedback loops).

China offers an unprecedented opportunity for systems-oriented pediatric obesity research for several reasons, including its: large population size, large geographic area, distinct regional contextual variation, rapid economic growth, and many social- environmental transformations over the past three decades, including dramatic changes in its food systems and the steep growth of the fast food industry. Some of the datasets to be used include millions of children and a large number of families; and some also contain rich measures of the local communities.

The large variance and change in macro-level contextual variables and in health outcomes, including obesity and many other non-communicable diseases, can help advance understanding of the etiology and disparities in these health outcomes in the U.S. through comparative studies. This will broaden the range of potential environmental and policy intervention options to be tested. Findings will have many important policy implications for the U.S. and other countries, e.g., in reexamining national food policies and programs and in assessing potential options to fight the obesity and chronic disease epidemic. In addition, the insight gained regarding the complex causal loops and systems models will help guide future research in the field. The project will benefit from the research team's other ongoing NIH-funded projects that focus on the U.S.

Project 4: A US National Study: Causes and Interventions for Childhood Obesity: Innovative Systems Analysis

Obesity has become a public health crisis in the United States as approximately 1/3 of US children and 2/3 US adults are overweight or obese. Obesity is believed as the result of a complex interplay between biological, behavioral, cultural, social, environmental and economic dynamics operating at multiple levels. Studying such complex dynamics is a challenge using traditional analytical approaches. This project aims to meet several urgent needs in the field, including both empirical results and methodological issues. The central hypothesis is that the determinants of individuals' energy balance related behaviors (EBRB) and body weight outcomes involve complex, dynamic processes including various feedback loops across multi-level factors.

The project has four specific aims: Aim 1: Using innovative, integrated conceptual framework and multilevel statistical analysis approaches, to examine the influences and interactions between individual, family and environmental factors on childhood obesity; Aim 2: Using agent-based models (ABM) to test simple rules (e.g., how children may interact with their social and built environments) that help explain individuals' EBRB and obesity risk and the changes in population level rates of these outcomes; Aim 3: To determine the key contextual drivers of the childhood obesity epidemic at the population level (i.e., time trends); and Aim 4: To identify and characterize promising intervention/policy strategies.

The systematic analysis will be conducted using a set of innovative, sophisticated methods including multilevel models and systems analysis models for analyses of empirical and simulation data. Data from national surveys including cohort studies linked with contextual measures from other data sources will be used. Our methodological products will benefit future studies, and our empirical findings will help clarify several controversies surrounding the causes of childhood obesity epidemic and help guide future interventions.

  

Other Selected Related Key Active Projects (not funded directly by the NIH U54 Center grant)

1. “Understanding Disparities in Obesity and Its Comorbidities in the U.S.”  Funding NIH/NIDDK (R01DK81335-01A1, PI Youfa Wang)

Goal: The study is a systematic investigation to understand the individual-, family-, and community-level causes of ethnic/SES disparities in obesity and its comorbidities, including type 2 diabetes and hypertension in the US using an interdisciplinary approach.

2. "Evaluation of Childhood Obesity Prevention and Management Programs" Funding: Agency for Healthcare Research and Quality (AHRQ, PI Youfa Wang)

Goal: To conduct a systematic review and meta-analysis to assess the effects of interventions directed at children and/or their families (including school-based and non-school based programs, as well as those related to policies and the built environment) on childhood obesity and related conditions. The study will also look at the interventions effects on children's related knowledge, beliefs and attitudes. The project may help guide future interventions and policies in the US, and other countries fighting this growing global epidemic.

3. "Multilevel communications and access strategies to improve the food environment” Funding: NIH / NHLBI (1R21HL102812-01A1, PI Joel Gittelsohn)

Goal:  To conduct formative research and pilot pricing and social marketing intervention to change availability of healthy foods and promote them at the wholesaler, retailer and consumer levels.