The uploaded dataset contains data for n = 59 participants, generated in the analyses presented in this manuscript “Psychological stress and (poly)phenol intake in free-living healthy adults: An Ecological Momentary Assessment study”. Specifically, the data includes participant characteristics (gender, age, BMI, ethnicity, nationality) and habitual stress (as measured by the perceived stress scale, PSS), as well as daily stress and psychological wellbeing and daily dietary intake for 7 days. Detailed methods for analyses are provided in the manuscript.