Abstract
Breakfast, the first meal of the day, plays a critical role in energy balance and dietary regulation. Although normal weight-obesity (NW-O) is considered a body composition problem among female university students, whether breakfast skipping is associated with NW-O remains unknown. This study aimed to investigate the relationship between breakfast skipping and body composition, nutritional status, and chronotype in female university students with normal body mass index (BMI). Two hundred Japanese university students were divided into two groups: those who rarely ate breakfast (SKIP) and those who ate breakfast almost daily (TAKE). Body composition such as percentage of body fat (%BF), fat-free mass (FFM) and appendicular muscle mass (AMM), chronotype (Morningness-Eveningness Questionnaire; MEQ), dietary intake, and physical activity level (PAL) were compared between the two groups. Our results showed that PAL was not significantly different between the two groups. Although body weight and BMI were not significantly different between the two groups, %BF was significantly higher and FFM was significantly lower in the SKIP group than in the TAKE group. The SKIP group had a significantly higher proportion of body fat of >30 % (55.8 %) than the TAKE group (34.1 %). Although the total energy intake was not significantly different between the two groups, the percentage of fat intake was significantly higher in the SKIP group. The multiple regression analyses of all participants showed that %BF and AMM were negatively and positively associated with PAL and breakfast consumption frequency, respectively. The SKIP group had a significantly lower MEQ score and a significantly higher number of evening types (41.9 %) than the TAKE group (23.5 %). These results suggest that the habit of breakfast consumption and chronotype-specific lifestyle interventions are necessary to prevent NW-O. Keywords Breakfast " Normal weight obesity " Body fat " Muscle mass " Energy intake " Morningness-Eveningness Questionnaire.