The influence of chronotype on the body mass index of U.S. college students

Abstract

Objectives The relationship between a college student’s chronotype and body mass index (BMI) is important to understand for university decision makers who want to build healthy and inclusive academic communities. This study aimed to evaluate how a student’s chronotype influences their BMI. Material and Methods Participants were college students from Oral Roberts University (n=384) with a mean age of 18.94 years, a mean BMI of 24.7kg/m 2 , and a mean morningness-eveningness questionnaire (MEQ) score of 47.65. Results BMI values were significantly correlated with both chronotype (r=-.11, β=-.09, p=.03) and age (r=.12, β=.53, p=.02). The rate at which BMI increased with age depended upon the student’s chronotype (β=.81-.005 / MEQ, p=.005). The later the chronotype, the higher the rate of increase. Race had no significant influence on MEQ or BMI values except in the case of students who identified as Black and female. These students were found, on average, to have significantly higher BMI values (p<.01). Conclusion For college students, BMI tends to increase over time and at a rate that is dependent upon chronotype. The later the chronotype, the faster the rate at which BMI increases. BMI values were found to be significantly higher for Black females. However, this result is potentially spurious, as BMI does not take into account differences in body composition between genders and race/ethnicity groups.

Associations of body composition with physical activity, nutritional intake status, and chronotype among female university students in Japan

“…Finally, as this was a cross-sectional study conducted at three universities with a limited number of participants, future research should examine changes in body composition in relation to changes in chronotypes and lifestyle behaviors. Although the sample size in this study was similar to that in recent studies on the association between chronotype and body composition in university students [ 7 , 9 , 11 ], further research is required to investigate this association at more universities with a larger number of participants.…”

“…Previous studies have suggested that the association between BMI and chronotype may vary based on factors such as location, age, and gender [ 9 ], as well as among different racial/ethnic groups [ 7 ]. However, our study with Japanese female students found that body composition was related to chronotype and physical activity, similar to a previous study with German students (which did not investigate nutrient intakes) [ 11 ].…”

“…Recent studies have also reported an association between chronotype and body physique in university students. For instance, a study of 384 students (150 males and 234 females) from the United States found a significant increase in body mass index (BMI) with age and lateness of chronotype and later chronotypes gaining weight faster than early chronotypes [ 7 ]. Another study with a larger sample size also concluded that university students with ET were more likely to be affected by overweight/obesity [ 8 ].…”

Gender peculiarities of blood pressure changes in patients with arterial hypertension and different biorhythms

“…The obtained results may be related to age, in particular, the leveling of the role of reproductive hormones, which are closely related to the evening type in young men and the morning type in pre-menopausal women [35; 36]. It was also found that BMI increases significantly with age and with index of composite scale of morningness, evening chronotypes gaining weight faster than morning chronotypes [37].…”

Exploring the role of sex in the association of late chronotype on cardiorespiratory fitness

“…However, these studies found conflicting results. Studies spanning adolescents to older adults found that evening chronotypes had greater body mass indexes (BMI; kg•m −2 ) (Arora & Taheri, 2015;Bloom et al, 2022;Teixeira et al, 2022), while other studies in similar age groups found no relationship between chronotype and BMI, waist circumference, or body fat (Kandeger et al, 2018(Kandeger et al, , 2019Lai & Say, 2013;Mota et al, 2016;Sato-Mito et al, 2011;Teixeira et al, 2018).…”