JMIR Publications

ABSTRACT

Background:

Chronotype (morningness-eveningness) and irregular sleeping habits or social jetlag (SJL) are related to eating behavior and health. Previous studies have only analyzed the association of sleep behavior with meal skipping, mealtime, mealtime regularity, and daily total energy/nutrient intake, while none have discussed the contents of each meal (breakfast, lunch, and dinner).

Objective:

Detailed eating habits among each chronotype and individual basic characteristics were investigated.

Methods:

Meal pattern datasets of participants (men, n=1,352; women, n=3,605; age 20–64 years) were obtained as averages over a 1-month period using the data stored in the food-log app. The relationships between food logs, chronotype/SJL measured by the Munich ChronoType Questionnaire, other basic characteristics, and health parameters were examined.

Results:

Evening chronotype and larger SJL were related to higher body weight, lower breakfast and higher dinner intake, lower breakfast and higher night snack frequencies, later food time, irregular mealtimes, and lower physical activity. Although there were many significant changes in time-dependent daily nutrient intake with chronotype/SJL, multiple regression analyses revealed specific nutrients. Morning chronotype and smaller SJL correlated with higher fiber intake and lower lipid intake when the daily total amount of each nutrient was analyzed. Morning chronotype was also correlated with higher breakfast carbohydrate and lunch fiber, as well as lower dinner carbohydrate and dinner protein levels. Smaller SJL was associated with higher breakfast carbohydrate and lunch fiber intake and lower daily total energy intake.

Conclusions:

The current study revealed that people who were morning chronotype or had small SJL showed healthy dietary conditions (higher fiber and lower lipid intake with bigger breakfast and lower dinner amount) with healthy body composition.