TY  - JOUR
A1  - Kawasaki, Yui
A1  - Akamatsu, Rie
A1  - Fujiwara, Yoko
A1  - Omori, Mika
A1  - Sugawara, Masumi
A1  - Yamazaki, Yoko
A1  - Matsumoto, Satoko
A1  - Iwakabe, Shigeru
A1  - Kobayashi, Tetsuyuki
T1  - Later chronotype is associated with unhealthful plant-based diet quality in young Japanese women
JF  - Appetite : multidisciplinary research on eating and drinking
N2  - Background:
Having a late chronotype, that is, the tendency to go to sleep and wake up at later hours, influences an individual's physical and mental health. Despite a few studies noting the association of chronotype with healthy dietary patterns, this relationship remains unclear. 

Purpose:
This study aimed to describe the association of chronotype with healthful and unhealthful plant-based diet quality in female Japanese undergraduate students. 

Design:
Cross-sectional. 

Participants and setting:
A total of 218 female university students in Tokyo, Japan. 

Main outcome measures: 
Healthful and unhealthful plant-based dietary index-Japanese version (hPDI-J and uPDIJ), calculated using the validated brief-type self-administered diet history questionnaire. 

Statistical analyses performed:
A five-model stepwise multiple linear regression analysis was conducted. Independent variables were hPDI-J and uPDI-J scores, and dependent variables were various lifestyle habits related to the circadian rhythm and demographic characteristics.

Results:
Mean (standard deviation) sleep duration, midpoint of sleep, sleep latency time, and social jetlag were 411 (60) min, 03:56 (00:57), 21 (27) min, and 50 (39) min, respectively. Chronotype and several variables, such as residential status, energy and alcohol intake, and nutritional knowledge, were associated with healthful and unhealthful plant-based diet quality. Individuals who had higher hPDI-J scores were more likely to have an earlier chronotype (13 = -0.168, P = 0.019) and better nutritional knowledge (13 = 0.164, P = 0.022) than those with lower hPDI-J scores. Individuals were more likely to have higher uPDI-J scores if they were living alone (13 = -0.301, P < 0.001), had a later chronotype (13 = 0.181, P = 0.001), higher frequency of snacking (13 = 0.164, P = 0.019), lower total energy (13 = -0.445, P < 0.001), and worse nutritional knowledge (13 = -0.172, P = 0.001). 

Conclusion:
This study provided new evidence as to the relationship between sleep and dietary habits, the interaction of which may affect women's health.
KW  - Chronotype
KW  - Plant-based diet
KW  - Sustainability
KW  - University students
KW  - Female
Y1  - 2021
U6  - https://doi.org/10.1016/j.appet.2021.105468
SN  - 0195-6663
SN  - 1095-8304
VL  - 166
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  -