Direct and indirect effects of food and nutrition security on dietary choice and healthfulness of food choice: causal mediation analysis

Authors: Thomson, Jessica; LANDRY, ALICIA - University Of Central Arkansas; Walls, Tameka

Submitted to: Current Developments in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/11/2024
Publication Date: 2/2/2024
Citation: Thomson, J.L., Landry, A.S., Walls, T.I. 2024. Direct and indirect effects of food and nutrition security on dietary choice and healthfulness of food choice: causal mediation analysis. Current Developments in Nutrition. 8(2):102081. https://doi.org/10.1016/j.cdnut.2024.102081.
DOI: https://doi.org/10.1016/j.cdnut.2024.102081

Interpretive Summary: Food insecurity limits a household’s ability to get enough food due to lack of money and other resources and it affects over 10% of (13 million) households in the United States. Nutrition security, a relatively new concept, focuses on the ability to get food that supports health and well-being. Similarities and differences between the two concepts in terms of associations with food choice are lacking. Additionally, determining if environmental or household characteristics affect relationships between food and nutrition security and food choice is needed. Models were built using an existing observational dataset to determine how food insecurity and nutrition insecurity affect food choice by acting through limited availability of foods and barriers to making healthful meals. Food choice scores were lower for individuals with food/nutrition insecurity as compared to individuals with food/nutrition security. Effects of food/nutrition insecurity on food choice did not appear to act through limited availability of foods but effects did appear to act through barriers to making healthful meals. However, when availability of food was limited or meal preparation barriers were present, food choice scores were similar between individuals with nutrition insecurity and those with nutrition security. Thus, environmental and household barriers to purchasing and preparing healthful meals have negative effects on a household’s ability to decide what to consume regardless of their nutrition security status. Strategies and policies that remove households’ barriers to making healthful meals may help lessen burdens of both food and nutrition insecurity.

Technical Abstract: Background: Links between dietary intake and food security are well established but less is known about how food and nutrition security affect a household’s ability to decide what they eat. The purpose of the study was to quantify and compare causal pathways from (1) food and nutrition security to dietary choice and (2) food and nutrition security to healthfulness of food choice while also testing for potential mediation by perceived limited availability of foods and utilization barriers to healthful meals in the pathways. Methods: Secondary analysis of an existing dataset was conducted using methods designed for causal mediation analysis with observational data. Exposures included food insecurity and nutrition insecurity; mediators included perceived limited availability and utilization barriers; outcomes included dietary choice and healthfulness choice; and covariates included income and education. Results: Dietary choice was 0.9-1.1 points lower for participants with food/nutrition insecurity vs participants with food/nutrition security (direct effects). Neither mediation nor moderation effects by perceived limited availability were present. Mediation by utilization barriers was present indicating 17% and 11%, respectively, of the effects of food and nutrition security on dietary choice could be contributed to utilization barriers. Moderation by utilization barriers was only present for nutrition security (differences in dietary choice only present when barriers were low). Healthfulness choice was 0.6-0.7 points lower for participants with food/nutrition insecurity vs participants with food/nutrition security (direct effects). Mediation by perceived limited availability was not present although moderation was present for nutrition security (differences in healthfulness choice only present when perceived limited availability was low). Mediation by utilization barriers on healthfulness choice was not present although moderation was present for nutrition security (differences in dietary choice only present when barriers were low). Conclusions: Food and nutrition security affect food choices with utilization barriers acting as an intermediary step. When environmental and household utilization barriers to healthful food purchasing and preparation are high, the ability to decide what to consume does not differ between households with nutrition security and those with nutrition insecurity. Strategies and policies that remove household utilization barriers may help lessen burdens of both food and nutrition insecurity.