Protocol - Food Swamp

Description

The presence of a food swamp is calculated using the traditional Retail Food Environment Index per county, which includes the number of fast food restaurants and convenience stores divided by the number of grocery stores and supermarkets. The number of grocery stores, fast food restaurants, and convenience stores is determined at a county level using data from the Food Environment Atlas.

Specific Instructions

If current address (see PhenX Demographics domain, Current Address measure) has been collected for a study respondent, then it is possible to use geocoding to link the address of a study participant to his or her local neighborhood (a geographic area), typically by a census-defined unit, such as a census block group or a census tract or by ZIP Code.

Availability

Available

Download PDF

Protocol

Traditional Retail Food Environment Index

Accessing Food Store Data at the County Level

All county-level food-store data is sourced from the Food Environment Atlas found at https://www.ers.usda.gov/data-products/food-environment-atlas/data-access-and-documentation-downloads/. An excel file can be downloaded to further extract data at a county level.

According to the U.S. Census Bureau, County Business Patterns, the following food environment variables are defined as:

Grocery Stores - The number of supermarkets and grocery stores in the county. Grocery stores include establishments generally known as supermarkets and smaller grocery stores primarily engaged in retailing a general line of food, such as canned and frozen foods; fresh fruits and vegetables; and fresh and prepared meats, fish, and poultry.

Fast Food Restaurants - The number of limited-service restaurants in the county. Limited-service restaurants include establishments primarily engaged in providing food services where patrons generally order or select items and pay before eating. Food and drink may be consumed on premises, taken out, or delivered to the customer’s location.

Convenience Stores/Food Marts - The number of convenience stores in the county. Establishments known as convenience stores or food marts are primarily engaged in retailing a limited line of goods that include soda, snack foods, etc.

Calculating the Traditional Retail Food Environment Index

After downloading the data for a given county, the traditional Retail Food Environment Index may then be calculated as follows:

Traditional Retail Food Environment Index (RFEI) =

(Fast Food / Limited Service Establishments + Convenience Stores) / (Grocery Stores / Super Markets)

Additional information may be found in the related publication at: https://dx.doi.org/10.3390%2Fijerph14111366

The RFEI can be categorized as following:

800 m buffer:

below 3.0

3.0 – 4.9

5.0 and above

1600 m buffer

below 6.0

6.0 – 9.9

10.0 and above

The number indicates the times greater of unhealthy food access (i.e. a RFEI of 3 indicates there are 3 times more unhealthy food retailers vs healthy food retailers in a given radius). A higher RFEI has been correlated with a higher obesity rate compared to a lower RFEI.

Personnel and Training Required

Knowledge of census data products and websites, such as the U.S. Census Bureau website (https://www.census.gov/programs-surveys/cbp.html) and the ability to use U.S. Department of Agriculture products and websites, such as the Food Environment Atlas (https://www.ers.usda.gov/data-products/food-environment-atlas/go-to-the-atlas)

The extracted data will need to be manipulated, and the traditional RFEI needs to be calculated.

Equipment Needs

Access to a desktop or laptop computer with Internet access to download data from the Food Environment Atlas (https://www.ers.usda.gov/data-products/food-environment-atlas/go-to-the-atlas). Optional statistical analysis can be executed using Stata/SE software.

Requirements

Requirement Category	Required
Major equipment	No
Specialized training	No
Specialized requirements for biospecimen collection	No
Average time of greater than 15 minutes in an unaffected individual	No

Mode of Administration

Secondary Data Analysis

Lifestage

Infant, Toddler, Child, Adolescent, Adult, Senior, Pregnancy

Participants

Not applicable; derived from publicly available secondary data

Selection Rationale

The traditional Retail Food Environment Index is an objective measure of food swamps that is easy to calculate and has been shown to be correlated with county-level obesity rates.

Language

English

Standards

Standard	Name	ID	Source
Logical Observation Identifiers Names and Codes (LOINC)	PhenX - food swamp protocol 290501	104563-2	LOINC

Derived Variables

None

Process and Review

Not applicable

Protocol Name from Source

Traditional Retail Food Environment Index (RFEI)

Source

Cooksey-Stowers, K., Schwartz, M. B., & Brownell, K. D. (2017). Food swamps predict obesity rates better than food deserts in the United States. International Journal of Environmental Research and Public Health, 14(11), 1366.

General References

California Center for Public Health Advocacy, PolicyLink, & the UCLA Center for Health Policy Research. (2008, April). Designed for disease: The link between local food environments and obesity and diabetes. Retrieved from https://escholarship.org/uc/item/9zc7p54b

Economic Research Service (ERS), U.S. Department of Agriculture (USDA). (2019). Data access and documentation downloads. Retrieved from

https://www.ers.usda.gov/data-products/food-environment-atlas/data-access-and-documentation-downloads/

Economic Research Service (ERS), U.S. Department of Agriculture (USDA). (2019). Food Environment Atlas. Retrieved from https://www.ers.usda.gov/data-products/food-environment-atlas/go-to-the-atlas/

McGuirt, J. T., Jilcott Pitts, S. B., & Gustafson, A. (2018). Association between spatial access to food outlets, frequency of grocery shopping, and objectively-assessed and self-reported fruit and vegetable consumption. Nutrients, 10(12), 1974.

Murphy, M., Badland, H., Jordan, H., Koohsari, M. J., & Giles-Corti, B. (2018). Local food environments, suburban development, and BMI: A mixed methods study. International Journal of Environmental Research and Public Health, 15(7), 1392.

Lucan, S. C., Maroko, A. R., Seitchik, J. L., Yoon, D. H., Sperry, L. E. & Schechter, C. B. (2018). Unexpected neighborhood sources of food and drink: Implications for research and community health. American Journal of Preventive Medicine, 55(2), e29–e38.

Spence, J. C., Cutumisu, N., Edwards, J., Raine, K. D., & Smoyer-Tomic, K. (2009). Relation between local food environments and obesity among adults. BMC Public Health, 9, 192. doi: 10.1186/1471-2458-9-192

Protocol ID

290501

Variables

Export Variables

Variable Name	Variable ID	Variable Description	dbGaP Mapping
PX290501_Food_Swamp_Environment_Convenient_Store
	PX290501030000	The number of convenience stores in the more county. Establishments known as convenience stores or food marts are primarily engaged in retailing a limited line of goods that include soda, snack foods, etc.` show less	N/A
PX290501_Food_Swamp_Environment_Fast_Food_Restaurants
	PX290501020000	The number of limited-service restaurants in more the county. Limited-service restaurants include establishments primarily engaged in providing food services where patrons generally order or select items and pay before eating. Food and drink may be consum show less	N/A
PX290501_Food_Swamp_Environment_Grocery_Store
	PX290501010000	The number of supermarkets and grocery more stores in the county. Grocery stores include establishments generally known as supermarkets and smaller grocery stores primarily engaged in retailing a general line of food, such as canned and frozen foods; fres show less	N/A

Structural Social Determinants of Health

Measure Name

Food Swamp

Release Date

May 11, 2020

Definition

“Food swamp” describes areas with a high density of establishments selling high-calorie fast food and junk food relative to healthier food options.

Purpose

Food swamps have a statistically significant effect on increased adult obesity.

Keywords

Retail Food Environment Index, RFEI, Social Determinants of Health, fast food restaurants, grocery stores

Measure Protocols

Protocol ID	Protocol Name
290501	Food Swamp

Publications

Burnett-Bowie, S. A. M., et al. (2024) The American Society for Bone and Mineral Research Task Force on clinical algorithms for fracture risk report. Journal of Bone and Mineral Research. 2024 May; 39(5): 517-530. doi: 10.1093/jbmr/zjae048

Bartholomew, T. S., et al. (2024) Project CHARIOT: study protocol for a hybrid type 1 effectiveness-implementation study of comprehensive tele-harm reduction for engagement of people who inject drugs in HIV prevention services Addiction Science & Clinical Practice. 2024 March; 19(1). doi: 10.1186/s13722-024-00447-9

Davidson, J., et al. (2022) From Genes to Geography, from Cells to Community, from Biomolecules to Behaviors: The Importance of Social Determinants of Health. Biomolecules. 2022 December; 12(10): 7. doi: 10.3390/biom12101449