Objective: Despite the fact that the total energy intake of Japanese people has decreased, the percentage of obese people has increased. This suggests that the timing of meals is related to obesity. The purpose of the study was to investigate the relationship between the timing of meals and obesity, based on analyses of physical measurements, serum biochemical markers, nutrient intake, and lifestyle factors in the context of Chrononutrition.
Participants and methods: We analyzed data derived from 766 residents of Toon City (286 males and 480 females) aged 30 to 79 years who underwent detailed medical examinations between 2011 and 2013. These medical examinations included. (1) physical measurements (waist circumference, blood pressure, etc.); (2) serum biochemical markers (total cholesterol, etc.); (3) a detailed questionnaire concerning lifestyle factors such as family structure and daily habits (22 issues), exercise and eating habits (28 issues), alcohol intake and smoking habits; (4) a food frequency questionnaire based on food groups (FFQg); and (5) a questionnaire concerning the times at which meals and snacks are consumed.
Results: The values for body mass index (BMI) and waist circumference were higher for participants who ate dinner less than three hours before bedtime (<3-h group) than those who ate more than three hours before bedtime (>3-h group). The Chi-square test showed that there was a significant difference in eating habits, e.g., eating snacks, eating snacks at night, having dinner after 8 p.m., and having dinner after 9 p.m., between the <3-h group and the >3-h group. Multiple linear regression analysis showed that skipping breakfast significantly influenced both waist circumference (β = 5.271) and BMI (β = 1.440) and that eating dinner <3-h before going to bed only influenced BMI (β = 0.581).
Conclusion: Skipping breakfast had a greater influence on both waist circumference and BMI than eating dinner <3-h before going to bed.
Keywords: chrononutrition; obesity; skipping breakfast.