PROJECT SUMMARY Cardiovascular disease has declined dramatically in all US adults except young women, whose rates remain stagnant. Young women who are Black or low-income carry the highest burden. Professional groups agree that the period around pregnancy is an ideal target for primordial and primary prevention efforts. Diet is a cornerstone in cardiovascular disease prevention, but this research is based on older adults, and is unlikely to generalize to the childbearing years, when changes to lifestyle and physiology alter diet and nutrient needs, and social determinants of health pose additional barriers. There are major gaps in our understanding of the dietary patterns that optimize short- and long-term postpartum cardiovascular health. Further, we do not know whether postpartum dietary patterns can mitigate the excess risk related to having a prior adverse pregnancy outcome, and more broadly, the groups that most benefit from dietary modification. We will fill these knowledge gaps by establishing the role of longitudinal dietary patterns in the development of cardiovascular disease and risk factors from periconception to 10 years postpartum. We propose a cost- efficient secondary analysis of existing data from 4048 racially- and socioeconomically-diverse participants in the nuMoM2b-Heart Health Study who had in-person study visits at 6‒13 weeks’ gestation as well as 3 and 10 years postpartum. First, we will estimate the effect of longitudinal dietary patterns on 3- and 10-year postpartum risk of incident hypertension, incident metabolic syndrome, and their risk factors, and explore how social determinants of health interact with dietary patterns to influence these risks. Then, we will estimate the extent to which postpartum dietary patterns can reduce the excess 3- and 10-year postpartum cardiovascular risks among individuals with an adverse pregnancy outcome (gestational hypertension, gestational diabetes, and preterm birth). Finally, we will identify optimal dietary patterns for groups of childbearing individuals based on factors such as race/ethnicity, socioeconomic status, community deprivation, adverse pregnancy outcomes, preexisting conditions, BMI, early-pregnancy and postpartum cardiometabolic markers, and postpartum weight. This work will deliver timely, high-quality evidence to providers and policymakers on the ideal dietary patterns for primordial and primary prevention of postpartum cardiovascular disease for vulnerable populations. Our work will improve medical practice and public health by identifying a specific, clinically actionable set of dietary guidelines that will target limited resources in critical time periods to individuals who will have the greatest benefit. Our innovative and significant project will inform strategies to alter dietary patterns for improving future cardiovascular morbidity and mortality and reduce its long-standing disparities.

PROJECT NARRATIVE The cardiovascular health of young women, especially women of color and low-income women, is poor during and after pregnancy, but we know little about the reasons for this and what to do about it. Although it is well accepted that a healthy diet is one of the most important behaviors people can target to prevent cardiovascular disease, research is needed on diet among young pregnant and postpartum women. Our work will guide the design of programs to alter diet to improve young women's cardiometabolic health and reduce its inequalities.