Dietary diversity score correlates with nutrient intake and monetary diet cost among Japanese adults

Dietary diversity is an indicator of diet quality. Dietary diversity has been suggested to result in good nutrient intake, but it can affect dietary cost. We examined whether dietary diversity correlates with nutrient intake and monetary diet cost.

We used data for 3985 individuals (age range: 20-64 years) from the 2014 Japan National Health and Nutrition Survey (NHNS). Dietary diversity was assessed using the food variety score (FVS; the number of foods) and dietary diversity score (DDS; the number of food groups, range: 1-14). Mean energy and nutrient intake from NHNS, and diet cost from the National Retail Price Survey were compared among FVS quartiles using the Kruskal-Wallis test, and between 2 groups with median DDS using the Mann-Whitney U test.

Mean (SD) FVS and DDS per day were 22.3 (7.2) and 9.8 (2.0), respectively. For most nutrients, intake per 4184 kJ was relatively high when FVS was high (p<0.001); however, carbohydrate intake was relatively high in the low-FVS group (p<0.001). For all nutrients with significant differences, intake was higher in the group with high DDS (≥10). Monetary diet cost was higher in the high-FVS and DDS groups compared with the low groups (p<0.001).

Intake of a variety of food and food groups resulted in higher intake of various nutrients as well as higher monetary diet cost. Additionally, care should be taken to avoid excessive intake of nutrients such as sodium and SFA that may result from diverse diets.