Association between the frequency of combined staple, main, and side dishes and nutritional adequacy among young Japanese women: A cross-sectional study.

BACKGROUND AND OBJECTIVES: Traditional Japanese diet comprises staple food, main dish, and side dish (SMS). Studies reporting the association between the frequency of SMS meals consumption and nutritional adequacy remain limited. We aimed to examine the association between the frequency of SMS meals consumption and nutritional adequacy in young Japanese women. METHODS AND STUDY DESIGN: In this cross-sectional study, data from 329 female nutrition students aged 18-25 years were analysed. The frequency of SMS meals consumption more than twice a day was assessed using a self-administered questionnaire, and dietary intake was evaluated using a validated food frequency questionnaire. We examined the association between SMS meals consumption and likelihood of not meeting the Dietary Goal (DG) or the Estimated Average Requirement (EAR) as defined in the Japanese Dietary Reference Intakes for Japanese. Trend analyses were performed to evaluate the relationship between SMS meal frequency and the number of nutrients not meeting the DG or EAR, while adjusting for potential confounders. RESULTS: Participants with high frequency of SMS meals consumption (5-7 days/week) had the lowest number of nutrients not meeting the EAR and DG, with significant linear trends observed across categories (p for trend <0.001 for DG; 0.001 for EAR). CONCLUSIONS: Frequency of SMS meals consumption is positively associated with improved nutrient intake among young Japanese women. However, given that the participants were dietetic students with relatively high nutrition literacy, caution is needed when generalising these findings to the wider population of young Japanese women.