Methods

What we do

The Global Food Research Program at UNC-Chapel Hill works toward its mission by developing in-depth longitudinal research in collaboration with partners around the globe and by providing technical assistance to universities, organizations, and governments on large-scale obesity prevention efforts.

A hallmark of our research collaborations has been understanding how changes in nutrition-related behaviors differentially impact various socioeconomic strata of society and how these complex behaviors perpetuate diet-related health disparities. Historically, we have focused on in-depth studies of trends in dietary and food purchasing patterns, race-ethnic- and income-related disparities, and evaluated the impact of an array of policies and programs on food purchases and diets. Our focus is increasingly on the design and evaluation of large-scale policy and regulatory options to improve diet quality across populations, with a focus on reducing consumption of ultra-processed foods and beverages.

In-Depth Longitudinal Studies

  • Our studies (US and global) have focused on policy, program, and project evaluation of voluntary industry efforts and well as government taxation of sugary beverages and junk food, mandatory front-of-package labeling, marketing restrictions, and other guidelines issued by various governmental bodies.
  • We also have decades of experience conducting longitudinal cohort studies — analyzing in-depth dietary, socio-economic, demographic, and contextual data — in countries including:

Analysis of Packaged Food Data

In the United States, we have explored the influence of industry on our food system (factory-to-fork) and its impact on the changing dynamics of food purchasing patterns and dietary intake:

  • We have used commercial data sources on packaged and processed food and beverage purchases, alongside public dietary intake data such as What We Eat in America, to monitor nutritional changes in Americans’ grocery purchases, both overall and among key sub-populations.
  • We have developed a deeper understanding of the nature of food purchased: processing, convenience, content of specific nutrients, and other health-related dimensions of the foods we purchase and consume.
  • We have monitored how ingredients such as sweeteners or added fibers have emerged and evolved in our packaged food supply over time, and how (or whether) they have been regulated.

Over the past decade, our unique skills and experience in working with food purchase data have expanded globally to evaluate population and subpopulation impacts of nutrition-related policy interventions, to study dynamic shifts in our food systems, and to attempt to identify ways to support healthier diets for all but especially among those historically more disadvantaged.

Technical Assistance to Policymakers

We use our extensive profile of research experience to provide technical assistance on large-scale regulatory activities to governmental entities in the United States and countries around the globe, as well as to multilateral agencies (e.g., the World Health Organization, World Bank) in these ways:

  • Create fact sheets summarizing research related to taxation, marketing bans, and other policy options
  • Provide scientific commentary and support on proposed nutrition policies
  • Assist government ministries in drafting evidence-based regulations, including:

How we do what we do

Quantitative methods

We have developed innovative methods and models to evaluate and inform the design of large-scale programs (e.g., food assistance, food feeding) and policies such as front-of-package labeling, food and drink taxes or subsidies, restrictions on junk food marketing, and other nutrition-related policies. These methods include:

  • Simulation modeling to estimate how various pricing policies such as taxes and subsidies may result in changes in food purchases and nutritional outcomes
  • Natural or quasi- experimental approaches to assess how policies are related to changes in demand or supply responses
  • Experimental grocery stores (in-person and online) to better understand the mechanisms behind behavior changes under more controlled but realistic environments

Mixed methods

We collaborate with qualitative researchers to provide opportunities for participants to share their experiences across the research process and facilitate avenues of exploration that enrich the evidence and enable questions to be answered more deeply. Whenever possible, we convene community advisory groups and local stakeholders to provide feedback and ensure instruments and messaging are appropriate and effective, and facilitate the interpretation of findings from our quantitative survey work.

Global Collaborations

Wherever we work, in the United States or globally, we always work hand-in-hand with local partners. We provide assistance on research design, survey design, and analytical methodologies based on our decades-long experiences working in food policy evaluation. We also provide infrastructure for data and project management support, relying on the knowledge and experiences of our local partners. All research outputs are collectively owned and reflect collective efforts in data analysis, collective presentation, and communication of findings.

Examples of our research partners include:

  • Brazil: Center for Epidemiological Studies in Health and Nutrition (NUPENS), School of Public Health, University of Sao Paulo
  • Chile: The Institute for Nutrition and Food Technology, University of Chile
  • China: The National Institute of Nutrition and Health, China CDC
  • Colombia: Faculty of Medicine, Pontifical Javeriana University
  • Jamaica and Barbados: Caribbean Institute for Health Research (CAIHR), University of the West Indies
  • Mexico: Center for Nutrition and Health Research, National Institute of Public Health
  • Peru: CRONICAS Centre of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia
  • Russia: Higher School of Economics and Institute of Sociology, Russian Academy of Sciences
  • South Africa: Priority Cost Effective Lessons for Systems Strengthening (Priceless), Wits School of Public Health; School of Public Health, University of the Western Cape (UWC)