Associations between Food Security Status and Dietary Inflammatory Potential within Lower-Income Adults from the United States National Health and Nutrition Examination Survey, Cycles 2007 to 2014

Background: Evidence suggests both that chronic inflammation mediates the association of food insecurity with adverse health outcomes and that diet may be a significant source of inflammation among food insecure individuals. Objective: To examine whether food security status is associated with dietary inflammatory potential. Design and participants: Cross-sectional data came from the National Health and Nutrition Examination Survey (NHANES), cycles 2007 to 2014 (n=10,630). The analysis sample is representative of noninstitutionalized US adults with an income-to-poverty ratio ≤3.00. Main outcome: Dietary Inflammatory Index (DII) score, calculated using the average of two 24-hour dietary recalls, was the main outcome measure. Statistical analysis: Type III F tests or χ² tests compared population characteristics by food security status, defined using the US Food Security Survey Module. Multivariable linear regression was used to estimate the association between food security status and the DII score and moderation by demographic factors. Survey weighting procedures accounted for the effects of stratification and clustering used in the NHANES study design. Results: When accounting for socioeconomic status, demographic factors, and health status, DII score was higher at greater levels of food insecurity (P=0.0033). Those with very low food security had a 0.31 (95% CI=0.12 to 0.49) higher DII score than those with high food security. Age moderated the association between food security status and DII score (interaction P=0.0103), where the magnitude of the association between DII score and severity of food insecurity was higher for those >65 years than for younger age groups. Conclusion: Food security status may be associated with dietary inflammatory potential, which is hypothesized to play a role in multiple chronic health conditions. Further research is needed to determine the causal nature of this relationship and evaluate how best to implement programs designed to address health disparities within food insecure populations.