中出 麻紀子

Few young Japanese adults regularly consume a well-balanced diet composed of staples, main courses, and sides. We hypothesised that adopting the recommended planetary health diet with regular breakfast consumption would promote well-balanced diets among young Japanese male undergraduates. This study aimed to examine the structural association between the planetary health diet with regular breakfast consumption and a well-balanced diet intake. This cross-sectional study included 142 male engineering undergraduates who completed a 2022 online questionnaire via Google Forms at a public university in Hyogo Prefecture. The planetary health diet comprises the consumption of the recommended eight items. A covariance structure analysis was performed in a hypothetical model with factors (regular breakfast consumption and eight items) potentially associated with the intake of a well-balanced diet at least twice daily. After excluding chicken dishes and nuts from the eight recommended items of the planetary health diet, goodness-of-fit became acceptable. Frequent consumption of the remaining six recommended items (fish, eggs, soybeans/soybean products, dairy foods, vegetables, and fruits) was significantly positively correlated with regular breakfast consumption and a significant positive path to a well-balanced diet. Among male university students, regular breakfast consumption and the planetary health diet may lead to a well-balanced diet.

Abstract This scoping review aimed to identify questionnaire-based dietary assessment methods for use in the National Health and Nutrition Survey (NHNS) in Japan. The search was conducted in three databases (PubMed, Web of Science, and Ichushi) to identify questionnaire such as food frequency questionnaire and dietary history questionnaire validated against dietary recalls or food records for the intakes of both food groups and nutrients among Japanese adults. Study quality was assessed based on previously developed criteria. We extracted the questionnaire characteristics and the design and results of the validation studies. We identified 11 questionnaires, with the number of food items ranging from 40 to 196, from 32 articles of good quality. In the validation studies, participants were aged 30–76 years and 90% of the articles used ≥3 d dietary records as reference. The number of nutrients and food groups with a group-level intake difference within 20% against the reference method ranged from 1 to 30 and 1 to 11, respectively. The range of mean correlation coefficients between questionnaire and reference methods were 0.35–0.57 for nutrients and 0.28–0.52 for food groups. When selecting a survey instrument in the NHNS from the 11 existing questionnaires identified in this study, it is important to select one with high group-level comparison and correlation coefficient values on the intended assessment items after scrutinizing the design and results of the validation study. This review may serve as a reference for future studies that explore dietary assessment tools used for assessing dietary intake in specific representative populations.

This study comprehensively examined the associations between shokuiku (food and nutrition education) during school years, current well-balanced diets, and current eating and lifestyle behaviours of Japanese female university students. A hypothetical model was developed using factors potentially associated with well-balanced diets. A simultaneous multipopulational analysis was performed according to the living arrangements of 148 female Japanese students (48.6% living alone) from a registered dietitian course. The analysis showed acceptable goodness of fit and a significant positive path from shokuiku during school years (living alone: standardised estimate 0.29, p = 0.004; with family: 0.32, p = 0.006) and a negative path from eating out frequency (-0.19, p = 0.039; -0.24, p = 0.017) towards a well-balanced diet. A significant negative path was identified from late bedtimes (-0.45, p < 0.001) and home meal replacement use frequency (-0.24, p = 0.010) in those living alone and from late-night snacking frequency (-0.27, p = 0.007) in those living with family. Well-balanced diets in female university students may be positively associated with shokuiku during school years and limited by a late bedtime, eating out, and home meal replacement use in those living alone, and by late-night snacking and eating out in those living with family.