We identified dish-based dietary patterns for breakfast, lunch, and dinner and assessed the diet quality of each pattern. Dietary data were obtained from 392 Japanese adults aged 20-69 years in 2013, using a 4 d dietary record. K-means cluster analysis was conducted based on the amount of each dish group, separately for breakfasts (n = 1462), lunches (n = 1504), and dinners (n = 1500). The diet quality of each dietary pattern was assessed using the Healthy Eating Index 2015 (HEI-2015) and Nutrient-Rich Food Index 9.3 (NRF9.3). The extracted dietary patterns were as follows: 'bread-based' and 'rice-based' for breakfast; 'bread', 'rice-based', 'ramen', 'udon/soba', and 'sushi/rice bowl dishes' for lunch; and 'miscellaneous', 'meat dish and beer', and 'hot pot dishes' for dinner. For breakfast, the HEI-2015 and NRF9.3 total scores were higher in the 'rice-based' pattern than the 'bread-based' pattern. For lunch, the HEI-2015 and NRF9.3 total scores were relatively high in the 'rice-based' pattern and low in the 'ramen' pattern. For dinner, the HEI-2015 total score was the highest in the 'meat dish and beer' pattern, and the NRF9.3 total score was higher in the 'hot pot dishes' than the 'miscellaneous' pattern. These results suggested that breakfast, lunch, and dinner have distinctive dietary patterns with different diet qualities.
Keywords: HEI-2015; Japan; NRF9.3; diet quality; dietary pattern; meal; mixed dish.