Association between vegetable intake and dietary quality in Japanese adults: a secondary analysis from the National Health and Nutrition Survey, 2003.

OBJECTIVE To investigate dietary quality among Japanese adults with a high vegetable diet, to consider dietary recommendation for vegetable intake. DESIGN AND SETTING In the cross-sectional study of the National Health and Nutrition Survey 2003, we conducted the secondary analyses. The food-weighing method in one-day assessed the dietary intake. From 11,630 subjects, 2,305 men and 2,312 non-pregnant/lactating women, aged 20-69 y, and with an energy intake between 1,500 and 3,712 kcal were selected. Associations between vegetable, nutrient-density, and food intake were analyzed according to tertile cutoff: low vegetable diet (LVD), medium vegetable diet (MVD), or high vegetable diet (HVD). Differences across subgroups were tested after age adjustment. RESULTS Mean vegetable intakes were 309 g for men and 318 g for women. Only 35% of Japanese met the vegetable intake (VI) recommendation of > or =350 g/d. VI had a positive association with age. Men 20-29 y-old and women 30-39 y-old were the subjects with the lowest VI. HVD subjects had higher intake for most food groups, whereas wheat in men; and wheat, sweets, and alcohol in women were negatively associated with VI. Main sources of energy for men and women with HVD were rice, wheat, and meat. HVD also had higher micronutrient-density. CONCLUSION These analyses demonstrated the beneficial effects of HVD on dietary quality in the population studied. We concluded recommendations for adequate vegetable intake are expected to improve diet quality among Japanese adults, especially for the group aged 20-39.