Chronotype and social jet-lag in relation to body weight, apetite, sleep quality and fatigue

Recent studies have shown a significant association between increased body weight (especially obesity) and the circadian setting - chronotype - as well as with living in accordance with the internal clock. The aim of this study was to explore the association between chronotype, social jet-lag (SJL), obesity and subjectively perceived sleep quality. A total of 1 680 people were screened by the Morningness-Eveningness Questionnaire (MEQ), Munich Chronotype Questionnaire (MCTQ), Pittsburgh Sleep Quality Index (PSQI) and Fatigue Severity Scale (FSS). In addition, their body mass index (BMI) was calculated. A significant relationship (negative) between (SJL) and MEQ score was found (p < 0.001). There was a relationship between higher SJL and morning affect and morning appetite, and a positive association between these variables and MEQ score. Evening chronotype was associated with higher FSS score in men (p = 0.015) and with higher BMI in women (p = 0.033). A relationship between evening chronotype and higher fatigue score and higher BMI was also confirmed. This is in line with other studies that show that individual differences in circadian settings (chronotype and social jet-lag rate) are important factors to be considered from the perspective of pathogenesis and treatment of many diseases or promoting awareness and responsibility at work.