Abstract Body: Latine and Hispanic Americans (LHA) experience poorer cardiometabolic outcomes than their non-Hispanic White (NHW) counterparts, potentially due to differential psychosocial stress exposure. Altered postprandial hemodynamic responses may reflect subclinical cardiometabolic risk and serve as an early link between psychosocial stress and poor cardiometabolic outcomes. Purpose: To determine if meal-induced changes in arterial dynamics are differentially related to daily psychosocial stress in healthy young LHA and NHW adults. We hypothesized that LHA participants would show blunted postprandial reductions in pulse pressure augmentation compared to NHW participants, which would be related to greater stressor exposure and stressor-related negative emotions. Methods: Twenty-three healthy young adults (12 LHA/11 NHW; 8M/15F; 23±3 y; 24±3 kg/m²) completed 7-day diaries capturing exposure to daily stressors and stressor-related negative emotions. Augmentation pressure (AP) and augmentation index (AIx) were then assessed via pulse wave analysis pre and post-ingestion of a liquid mixed meal (62% carbohydrate, 22% fat) providing energy equivalent 20% of basal metabolic rate (324±42 kcal). Repeated measures mixed-effects ANOVAs examined the effects of ethnicity and meal ingestion on AP and AIx. Mixed linear regression models tested whether ethnicity-dependent daily stress processes influenced meal-induced changes (Δ0-60 min postprandial) in AP and AIx. Where a significant interaction was observed, within-group partial correlation analyses were performed. Analyses were controlled for sex and the regression model including stressor-related negative emotion was also adjusted for total stressor exposure. Results: There were no group differences in stressor exposure or related negative emotions (p≥0.35). The meal induced a significant decrease in AIx (p=0.045), independent of ethnicity (p=0.11), but did not significantly affect AP (p=0.12). There was a significant interactive effect of ethnicity and stressor-related negative emotions on AIx (estimate=-1.28±0.53, p=0.030), but not AP (p=0.068). Stressor-related negative emotions were significantly associated with postprandial changes in AIx among LHA (r=0.72, p=0.046) and not NHW (r=-0.22, p=0.64). Conclusions: These data suggest that stress-related negative emotional responsiveness is associated with blunted postprandial hemodynamic adjustments in LHA adults, which may contribute to increased cardiometabolic risk.