Association of Dietary Variety and Diversity With Body Mass Index in US Preschool Children

Abstract

BACKGROUND AND OBJECTIVES: Dietary variety and diversity are recommended in dietary guidelines, but their association with BMI in US preschool-aged children is unknown. This study examined predictors of dietary variety and diversity and their association with child BMI z score (BMIz). METHODS: Primary caregivers responded to a food frequency questionnaire. Child anthropometry was obtained concurrently (n = 340) and prospectively (n = 264). Dietary variety scores and dietary diversity scores were computed. Multivariable linear regression was used to model predictors of these scores and their association with BMIz concurrently and BMIz change per year prospectively. RESULTS: The sample was 49.4% boys; 69.4% of the primary caregivers were non-Hispanic white and 46.2% had a high school education or less. Girls and older children had greater Fruit and Vegetable Variety (gender: P = .03, age: P < .001), Healthy Foods Variety (P = .02, P < .001), and Dietary Diversity (P = .04, P = .03) scores. Older children also had greater scores for Overall Variety (P < .001) and Moderation Foods (eg, high-fat, high-sugar foods recommended to be consumed in moderation) (P < .001). Having a non-Hispanic white primary caregiver (versus not) was associated with lower Dietary Diversity (P = .01). Greater Healthy Variety, Overall Variety, and Dietary Diversity were associated with greater annual increases in BMIz prospectively (β[SE] = 0.009 [0.004], P = .04; β[SE] = 0.007 [0.003], P = .02; β[SE] = 0.003 [0.001], P = .02, respectively), adjusted for energy intake. CONCLUSIONS: Greater dietary variety and diversity were prospectively associated with higher BMIz. Targeting dietary variety and diversity as an obesity prevention strategy in children requires careful consideration.