Association of meal component combinations with nutrient adequacy in Japanese adults

Consuming a diet that ensures adequate nutrient intake is essential to address all forms of malnutrition. In Japan, a meal combining staple food, main dish, and side dish is considered a balanced diet. This study was conducted to investigate the frequency of meals combining staple food, main dish, and side dish associated with nutrient adequacy.

This cross-sectional study included 6,264 adults. All data were obtained from the 2015 Health and Nutrition Survey in Shiga prefecture. Staple food, main dish, and side dish were each defined as a dish with primary ingredients of ≥50 g. Regarding the frequency, participants were divided into ≥2 and <2 times/d groups. The nutrient adequacy evaluated using the Dietary Reference Intakes for Japanese 2020 (DRIs-J) score is based on the reference values provided in the DRIs-J. The t-test was used to evaluate nutrient adequacy between the 2 groups.

Of the total participants, only 1,423 (22.7%) were classified into the ≥2 times/d group, and they had significantly higher DRIs-J scores than participants in the <2 times/d group (p < 0.001). The adequacy percentage of all nutrients except saturated fatty acid, particularly dietary fiber and most micronutrients, was > 1.5-fold higher in the ≥2 times/d group than in the <2 times/d group (p < 0.001).

This study provides important information that meals combining staple food, main dish, and side dish at least twice a day is effective in maintaining a diet with high nutrient adequacy.