Globally, chronic diseases that require ongoing medical attention, and limit daily living activities, are the leading cause of disability and mortality. The older population in the U.S. is rapidly growing, and the risk of chronic diseases is higher in this population, specifically older women. In 2018, 51.3% of women compared to 41.8% of men had two or more chronic conditions. Thus, the Women’s Health Initiative (WHI) study, Chapter 1, focused on preventing leading causes of death, disability, and frailty in older women. Phthalates are synthetic industrial compounds, Chapter 2, commonly added to daily used consumer goods, nutritional and dietary supplements, and plastic food packaging. Current literature suggests that phthalate exposure may be associated with an increased risk of chronic health outcomes, including excess adiposity via disruption of metabolic processes/adipocyte function and cardiovascular disease (CVD) via disruption of normal cardiac function. Thus, this dissertation aimed to evaluate these associations between dietary patterns, excess adiposity, CVD, and phthalate exposure in the prospective WHI study (n=161,808). In chapter 3, we evaluated how alignment to specific dietary patterns, dietary approach to stop hypertension (DASH), the alternative Mediterranean diet (aMed), and the dietary inflammation index (DII) are associated with urinary phthalate biomarker concentrations. Results of this study suggest that higher alignment with diets promoting consumption of whole fruits and vegetables, including the DASH and aMed, are associated with lower concentrations of phthalate biomarkers. In chapter 4, we evaluate the association between phthalate exposure and dual-energy x-ray absorptiometry (DXA) derived visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Our findings indicate that higher concentrations of phthalates are more strongly associated with increased VAT. In chapter 5, we evaluate the association between phthalate exposure and adjudicated incident cases of CVD. Our findings suggest that increased concentrations of phthalates may be associated with increased CVD risk among nonusers of hormone therapy. In conclusion, our findings suggest that phthalates are associated with increased VAT and may be associated with increased CVD risk. However, consumption of dietary patterns like the DASH and Mediterranean diets may be a non-invasive means of mitigating phthalate exposure and subsequent chronic disease risk.