# Multilevel Analysis of the Food and Physical Activity Environment and Adult Obesity Across U.S. Counties and States

## TL;DR

This study explores how food access, physical activity environments, and socioeconomic factors at the county and state levels are linked to adult obesity in the U.S.

## Contribution

The study introduces a multilevel analysis linking county- and state-level environmental and socioeconomic factors to obesity rates across over 3000 U.S. counties.

## Key findings

- Food insecurity, poverty, and high fast-food store density are positively associated with adult obesity.
- Access to recreational facilities and higher median income are linked to lower obesity rates.
- Environmental and socioeconomic factors show varying impacts across counties and states.

## Abstract

Public health relevance—How does this work relate to a public health issue?
Adult obesity remains a major public health challenge in the United States, with substantial geographic and social disparities across counties and states.This study examines how food access, physical activity environments, and socioeconomic conditions are associated with adult obesity at the county and state level.

Adult obesity remains a major public health challenge in the United States, with substantial geographic and social disparities across counties and states.

This study examines how food access, physical activity environments, and socioeconomic conditions are associated with adult obesity at the county and state level.

Public health significance—Why is this work of significance to public health?
The analysis uses a national multilevel framework to distinguish between county-level and state-level contextual influences on obesity prevalence.The findings highlight that structural and environmental conditions are linked with obesity patterns, even after accounting for socioeconomic and demographic factors.

The analysis uses a national multilevel framework to distinguish between county-level and state-level contextual influences on obesity prevalence.

The findings highlight that structural and environmental conditions are linked with obesity patterns, even after accounting for socioeconomic and demographic factors.

Public health implications—What are the key implications or messages for practitioners, policy makers and/or researchers in public health?
Results suggest that efforts to address obesity may benefit from considering local food environments, economic conditions, and access to physical activity resources together rather than in isolation.The findings underscore the importance of place-based and context-sensitive approaches when designing obesity prevention strategies.

Results suggest that efforts to address obesity may benefit from considering local food environments, economic conditions, and access to physical activity resources together rather than in isolation.

The findings underscore the importance of place-based and context-sensitive approaches when designing obesity prevention strategies.

Adult obesity rates have risen steadily across the United States over the past decade, with more than 40% of adults affected. Persistent geographic and demographic disparities exist in obesity prevalence across the nation. While prior research has examined individual or environmental associated factors of obesity, limited studies have addressed both physical activity and food environments across the nation using multilevel approaches. This cross-sectional ecological study (2014–2024) used a two-level random intercept model to assess the association between county- and state-level factors and adult obesity prevalence across over 3000 U.S. counties nested within 51 states. County-level associated factors included food insecurity, poverty, unemployment, median household income, limited access to stores, and the density of various food outlets (grocery stores, convenience stores, supercenters, fast-food restaurants, Supplemental Nutrition Assistance Program (SNAP)-authorized retailers, and farmers’ markets), along with access to recreational facilities. State-level factors included SNAP benefits per capita and the presence of soda and chip taxes. Variables were group-mean- or grand-mean-centered to distinguish within- and between-state effects. Results showed that food insecurity, poverty, unemployment, limited access to stores, and a higher density of fast-food and convenience stores were positively associated with adult obesity prevalence. While higher recreational facility access, supercenter availability, median household income, SNAP benefits per capita were associated with lower adult obesity prevalence, these associations varied in strength across counties and states. These results emphasize the need for place-based strategies that address both the physical activity and food environment in shaping obesity disparities.