Exploring the association of food security with mental health, diet quality, and nutrient exposure among low income groups in the U.S.

Low-income individuals face challenges of food insecurity which may negatively impact dietary and mental health outcomes. This thesis explores the mediation of social isolation in the relationship of food security to depression, resource use, and the links between situations of limited access to healthy food, dietary quality and nutrient exposure among low income households, covered in three chapters. Following an introduction in Chapter 1 to overview this work, Chapter 2 investigates the mediation of social isolation in the relationship of food insecurity, depression, and resource use among a cross-sectional sample of rural veterans. The findings showed that social isolation completely mediates the relationship between food insecurity and depression. Chapter 3 explores the association between limited resources for food and the quality of dietary intake among adult (18) low income women with children from Indiana. This was done by evaluating the relationship of individual questions of the U.S. Household Food Security Survey Module (U.S. HFSSM) to an indicator of dietary quality using the Healthy Eating Index (HEI). The results of the study identified two food security (U.S. HFSSM) questions that were related to lower diet quality and specific dietary components. Chapter 4 is a similar investigation as in Chapter 2 except a nationally representative sample of U.S. adults from the National Health and Nutrition Examination Survey was used and an indicator of nutrient exposure was also evaluated in relationship to the U.S. HFSSM questions along with the HEI. The study's findings showed that one U.S. HFSSM question was associated with lower diet quality among both households with and without children and lower nutrient exposure among households without children only. Two other questions were associated with lower diet quality and lower nutrient exposure among households without children only. The findings presented in this thesis may inform the design of intervention and policies that incorporate social isolation in alleviating food insecurity and improve mental health outcomes and in consideration of the design of nutrition security measures and indicators among vulnerable population.