Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)


Nutrition Science

Committee Chair

Heather A. Eicher-Miller

Committee Member 1

Regan L. Bailey

Committee Member 2

Bruce A. Craig

Committee Member 3

Richard D. Mattes


High prevalence of food insecurity and poor diet quality characterize the US low-income population qualifyingfor the Supplemental Nutrition Assistance Program (SNAP) when compared with higher income populations. The Supplemental Nutrition Assistance Program-Education (SNAP-Ed) is a federal nutrition education program available at no cost to the income-eligible population with the goal to improve diet qualitybypromoting adherence to the DietaryGuidelines for Americans (DGA) through nutrition education while also supporting the goal of SNAP to improve food security. Limited evidence suggests that SNAP-Ed improves diet-related outcomes such as food security, intake of fruits and vegetables, and other targeted positive health behaviors over short-term periods; however, the long-term impact of SNAP-Ed on these outcomes is unknown. The overarching aims of the research in this dissertation were to evaluate the effects of direct SNAP-Ed delivered through a series of nutrition education lessons at the individual level on the outcomes offood security and dietaryintake over along-term period using a randomized and controlled nutrition education intervention studydesign. An additional aim was to assess whether changes in food security or dietaryintake were influenced by specific program characteristics. The dissertation begins with a narrative review critically evaluating the small body of direct SNAP-Ed impact and outcome research literature on food security and dietary outcomes, concluding that inconsistent measurement tools and outcomes across studies along with weak studydesigns contribute to an inabilityto determine the effectiveness of SNAP-Ed to improve food security or dietarybehaviors. Due to the inconsistencies across studies, a meta-analysis or systematic review were not possible. The research studies presented in this dissertation fill agap in the literature and provide an example of the feasibilityof implementing rigorous research to investigate the impact of SNAP-Ed. Facilitation of 2 longitudinal randomized and controlled nutrition intervention studies with the 4 core SNAP-Ed lessons as the intervention provide the data for results presented in chapters 2-5. The evaluation of the impact of SNAP-Ed on food security outcomes among Indiana households with children found improved household food security score in the intervention group compared to the control group over the 1-year study period and provides strong support of the effectiveness of SNAP-Ed to assist SNAP in improving food security. The of improvement of 1.2±0.4 (P

status was negatively associated with overall diet quality and the dairy and whole grain diet quality components (P≤0.01) as measured bythe HealthyEating Index-2010. There was no difference between food secure and food insecure participants with regard to the large overall proportion of the studypopulation not meetingdaily serving recommendations in the DGA for fruits, vegetables, dairy, and whole grains, highlighting a strong need for nutrition intervention across this low-income population. An evaluation of the impact of aSNAP-Ed intervention on dietaryintake over a 1-year studyperiod determined the effect, if any, on mean usual nutrient intake, mean usual intake of food groups targeted bySNAP-Ed (fruits, vegetables, dairy, and whole grains), the proportion of the population at risk for inadequate nutrient intake, the proportion of the population not meeting the number of dailyfood group servings recommended in the DGA, diet quality, and diet quality components. The nutrients assessed were those considered to be under-consumed bythe US adult population and nutrients to increase according to the DGA (calcium, vitamins D, E, A, and C, magnesium, potassium, fiber, and folate). No long-term differences in mean usual nutrient intake, mean usual food group intake, the proportion of the population at risk for inadequate nutrient intake, the proportion of the population meetingintake of food group recommendations, or diet quality were found in the intervention group compared to the control group, except for a decrease in the sodium diet quality component score (p=0.02) among the intervention group. SNAP-Ed did not improve dietaryintake or quality amongSNAP-Ed-eligible Indiana adults. One explanation for the improvement in food securitybut not dietaryintake maybe that intervention group participants were successfully able to use the nutrition education they received to improve access to enough food to improve household food availability, but that stretching resources in order to have enough food was not able to also improve the nutrient quality of the food, thus participants did not improve dietaryintake. The possibilityfurther exists that other household members, such as children and especially young children, mayhave experienced improved diet qualitydue to SNAP-Ed because the adult SNAP-Ed participant is likelyto be responsible for food procuring, preparation, and distribution of food to other household members. Previous research supports that this individual usuallyprioritizes other household members’ quantity and quality of dietaryintake before their own. The results from the studies in this dissertation contribute strong evidence in support of the positive impact of SNAP-Ed on long-term food security and demonstrate that SNAP-Ed is a critical component to the multi-faceted solution to the pervasive public health problem of US food insecurity. These dietary outcome results point to a need for more research to understand whythe generallypositive findings in the emerging scientific evaluation literature regarding the impact of SNAP-Ed on diet-related outcomes do not translate to improvements in long-term habitual dietaryintake and quality.