Psychological distress mediates the association between daytime sleepiness and consumption of sweetened products: cross-sectional findings in a Catholic Middle-Eastern Canadian community

OBJECTIVE: To examine the associations between consumption of sweetened products, daytime sleepiness (DS) and psychological distress (PD) in a Catholic Middle-Eastern Canadian community, and to test the hypothesis that the association between DS and consumption of sweetened products is mediated by PD. DESIGN: A cross-sectional study. SETTING: A Catholic Middle-Eastern Canadian community. PARTICIPANTS: 186 men and women aged between 18 and 60 years. PRIMARY AND SECONDARY OUTCOME MEASURES: Sweetened product consumption was measured using a food frequency questionnaire (total sugars/day). DS and PD were measured using standardised questionnaires. The generalised linear model was used to estimate associations between sweetened product consumption, age, sex, self-reported body mass index, DS and PD. Baron and Kenny's four-step approach in addition to the Sobel test were used to establish mediation. RESULTS: Average DS score was 8.2 (SD=4.5) with 19.5% having excessive scores (>12). Mean PD score was 20.8 (SD=6.2) with 11.8% having high distress scores. Average consumption of sweetened products was 15.5 g/day (SD=13.9). Baron and Kenny's three steps to establish partial mediation were confirmed. First, DS was associated with consumption of sweetened products (p<0.03). Second, DS and PD were correlated (r=0.197; p<0.04). Third, PD was associated with consumption of sweetened products (p<0.01) when both PD and DS were entered as predictors in a multivariate regression. However, Baron and Kenny's fourth step to establish complete mediation was not met. The effect of DS on consumption of sweetened products controlling for PD was reduced, but it was not zero. Finally, the Sobel test was significant (2.14; p<0.03). CONCLUSIONS: The association between DS and consumption of sweetened products in the Catholic Middle-Eastern Canadian community is partially mediated by psychological distress. Further work should test this mediation relationship in larger samples and verify the potential effects of other sleep variables in this relationship.