Association of chronotype and sleep behaviors with mental well-being, eating behaviors, and adiposity traits: a cross-sectional study among a sample of urban Malaysian adults.

Background: We investigated the association of chronotype and sleep behaviors with mental well-being, eating behaviors, and adiposity traits among a sample of urban Malaysian adults at Sunway University and Sunway College, Selangor, Malaysia.

Methods: A total of 167 participants were recruited (male/female = 46/121; aged 22.0 ± 5.2). Chronotype was assessed via reduced Morningness-Eveningness Questionnaire (rMEQ). Participants tracked their sleep behaviors using an activity wristband (Xiaomi Mi Smart Band 5), and recorded their smartphone screen time usage. Psychometric measures - WHO-5 Well-being Index, Cognitive Distortion Questionnaire (CDQUEST), Three-Factor Eating Questionnaire-R18, Brief Self-Control Scale (BSCS), and Power of Food Scale. Blood pressures (BP), anthropometrics, and body composition like high waist circumference (WC), waist-hip ratio (WHR), waist-to-height ratio (WHtR), body mass index (BMI) and visceral fat level (VFL) were also measured.

Results: Men and women did not differ significantly in terms of chronotype and sleep behaviors, except Rapid Eye Movement (REM) sleep. Longer weekday total and deep sleeps significantly correlated with better WHO-5 well-being scores, while longer weekend time awake during sleep significantly correlated with greater cognitive distortion (higher CDQUEST scores). Longer average deep sleep significantly correlated with lower Cognitive Restraint (CR) but higher Food Available scores. Higher rMEQ scores (indicating morningness) significantly correlated with better WHO-5 well-being, BSCS Total and Restraint scores; and significantly correlated with decreased systolic and diastolic BP specifically among men. Evening-type participants had up to six-fold higher risk of becoming obese, and having high WC, WHR, and VFL; however, the significance was abolished after adjustment for socio-demographics. Indeed, WC, weight, WHtR, BMI, VFL, and resting metabolism were significantly higher among evening-types by analysis of covariance. BSCS Total and Impulsivity scores were significantly higher among neither-types. Lifestyle factors and smartphone screen time were not associated with chronotype or sleep behaviors.

Conclusions: Although chronotype and sleep behaviors did not differ between sexes, those with a morning chronotype had lower overall, central and visceral adiposity, better well-being and self-control. Those with good sleep behaviors also had better well-being, eating and appetitive behaviors. In conclusion, this study supports the continuous advocacy for a morning-chronotype and good sleep behaviors for better physical and mental health.