THE EFFECTS OF VARIETY IN FOOD CHOICES ON DIETARY QUALITY (DIVERSITY, CONSUMPTION, UNITED STATES)

The purpose of this study was to examine the effects of overall dietary variety, variety among major food groups, and variety within major food groups on dietary quality--specifically, nutritional adequacy and macronutrient balance. A study sample was selected from USDA's Nationwide Food Consumption Survey, excluding pregnant and lactating females and children under one year of age. Multiple correlation-regression analyses were performed to examine the relationships between each type of variety and each diet quality measure, controlling on age, sex, the number of foods, and all of their two-way interactions with variety. Nutritional adequacy was measured by a Mean Adequacy Ratio (MAR), an index of the percent of recommended intake for 11 nutrients. Macronutrient balance was measured as the percent of calories from fat.;For most of the models used to study variety in relation to MAR, all of the interactions were significant. When interactions were present, the same trends were seen regardless of the type of variety. Increases in variety were associated with greater increases in MARs for females than for males, for 11- to 69-year-olds than for children and older adults, and for persons with lower versus higher numbers of foods.;Though relationships were observed between each type of variety and MAR, none of the variety measures accounted for a sizeable proportion of the variation in fat intakes. For this reason, the interactions were not probed further. The implications of these findings, their limitations, and suggestions for further research are discussed.;The variety terms added a significant increment to the variation in MAR which was explained by each of the models. In the models which examined overall variety, variety among five major food groups, or variety within the five groups, the variety terms added about ten percentage points to the percent of variation accounted for by the control variables alone. In models which examined variety within single food groups, the variety terms did not contribute as much. Variety among the five major food groups explained as much of the variation in MAR as did variety within those groups.