ABSTRACT
Background:
Coffee is one of the most widely consumed beverages worldwide, with ongoing debate regarding its potential benefits and drawbacks for human health, particularly sleep quality. Simultaneously, dietary composition-especially a predominantly plant-based diet-has been linked to better health outcomes. This study aimed to investigate how coffee intake and dominant dietary components relate to sleep quality in physically active individuals, with consideration of additional lifestyle factors such as stress and emotional well-being.
Methods:
A cross-sectional survey was administered online and via QR codes displayed in sports facilities. Physically active adults (N = 392) completed a standardized questionnaire assessing sleep quality, stress, physical activity, and demographic data. Factor analysis identified underlying dimensions of interest, which were then used in K-Means clustering to group participants with similar response patterns. Statistical analyses, including the Kruskal-Wallis test and Dunn's post-hoc comparisons, determined differences in dietary and coffee consumption habits across factors and clusters.
Results:
Four factors emerged from the analysis: Stress, Health, Relaxation, and Emotional Well-being. Higher stress levels strongly correlated with poor sleep quality, while coffee consumption alone was not statistically linked to stress or sleep problems. Respondents who consumed more than two cups of coffee daily often clustered into groups reporting higher health and emotional well-being. A predominantly plant-based diet was significantly associated with better overall health scores and lower stress. Clustering analysis revealed that participants with the healthiest behaviors (Cluster 2) tended to follow plant-rich diets and reported lower stress levels and better sleep outcomes.
Conclusion:
In a physically active population, stress appears to be a more robust predictor of poor sleep quality than coffee consumption. Moderate coffee intake may even coincide with higher health and emotional well-being scores. The findings emphasize that coffee consumption does not adversely affect sleep quality, and in fact has a positive effect on emotional wellbeing and health.
