Overview

• The peer-reviewed PLOS One paper, published August 27, analyzed a cross-sectional survey (N=1,032) from New Zealand, the U.K., and the U.S., plus two New Zealand daily-diary studies (13 days, N=818; 8 days with Fitbit, N=236).
• Across all datasets, better sleep quality showed the strongest association with psychological well-being, with fruit and vegetable intake the next most robust predictor.
• Within-person analyses indicated that higher fruit and vegetable intake buffered the negative effect of a poor night's sleep on same-day well-being.
• Physical activity related to better well-being mainly at the day-to-day level within individuals, and Fitbit-measured activity corroborated patterns seen in self-reports.
• The authors underscore that the findings are observational and geographically limited, noting modest yet practical implications and calling for more diverse, causal research.