Association of 24-hour Movement Behaviour with Loneliness and Happiness in Japanese Adults: A Compositional Data Analysis with Isotemporal Substitution Model

Introduction: Loneliness and happiness levels are common regular emotions and can contribute to adults’ mental health. daily behaviours, such as sleep, sedentary behaviour (SB), moderate to vigorous-intensity physical activity (MVPA), and light-intensity physical activity (LPA), have been linked to various mental health outcomes. However, no prior study has employed compositional data analysis (CoDA) to examine these behaviours within 24 hours and their relationship to adults' loneliness and happiness. This study investigates how adults’ 24-hour movement behaviour patterns relate to these emotions. Methods: This cross-sectional study included 2,718 participants aged 20-59 from a Japanese online health survey conducted in 2023. Participants' 24-hour movement behaviours (sleep, SB, MVPA, LPA) were assessed using a questionnaire about their time use on a typical day. Loneliness was assessed using the UCLA 3-Item Loneliness Scale, and happiness was self-reported based on their current level of happiness. Compositional data analysis with logistic regression was performed to examine the associations between daily behaviour composition and the experiences of loneliness and happiness. Results: Among the 2,718 adults, 1,214 reported feeling lonely, and 739 feeling unhappy. More time spent in SB, relative to other behaviours, was associated with increased loneliness (OR=1.20, 95% CI: 1.06-1.37) and reduced happiness (OR=0.83, 95% CI: 0.72-0.95). Replacing SB time with sleep was linked to improved estimates of both loneliness and happiness. Substituting 5 to 30 minutes of SB with LPA was associated with lower odds of loneliness while substituting SB with MVPA was associated with higher odds of happiness. Conclusions: Greater time spent in SB was associated with increased loneliness and reduced happiness, suggesting that replacing SB with sleep and physical activity might be essential for improving adults' emotional well-being. These findings give adults insights into how their daily routines impact well-being.