PROJECT ABSTRACT Dementia is the 6th leading cause of death in the U.S. with marked disparities by socioeconomic status, gender, and race/ethnicity. Food insecurity is a common experience in U.S. children and adults, and it likely influences Alzheimer's Disease and Alzheimer's Related Dementias (AD/ADRD) via multiple mechanisms. Yet, there is almost no quantitative research evaluating food insecurity and AD/ADRD. The very limited prior work in this area is cross-sectional which introduces challenges: 1) the temporal ordering of food insecurity and cognitive performance is ambiguous; 2) researchers are unable to disentangle if acute vs. chronic food insecurity differentially impacts dementia risk; and 3) measuring cognitive assessments at a single time point precludes the possibility of evaluating cognitive decline. Through innovative uses of the U.S. Health and Retirement Study (HRS), and the National Longitudinal Survey of Youth, 1979 cohort (NLSY79), the proposed research fills this critical gap. Both data sources collect prospective information on food insecurity and dementia risk among older adults (HRS), and across the lifecourse (NLSY79). We will leverage the complementary strengths of these datasets to evaluate: [1] if food insecurity among older adults predicts dementia risk (Aim 1; HRS); [2] if lifecourse food insecurity (from ages 18 – 48) predicts dementia risk (Aim 2; NLY79); and [3] if Supplemental Nutritional Assistant Program (SNAP) benefit amount patterns (ages 18 – 48) predict dementia risk (Aim 3; NLY79; SNAP is a federal food insecurity alleviation program). This innovative work on lifecourse food insecurity is possible through our novel application of sequence analysis, which will be applied to markers of food insecurity collected over time in both nationally representative data sources. Our research questions focus on food insecurity, which is a modifiable target for AD/ADRD prevention that is biologically plausible, common, and potentially high impact through existing policy interventions, such as SNAP.