Seven-year tracking of dietary factors in young adults: the CARDIA study

Objectives: This report determines the extent to which young adults in the highest and lowest intake quintiles of 13 nutrients remain in the same or adjacent quintiles (i.e., “tracked”) relative to each other, over 7 years. Methods: Data from baseline and year 7 of the CARDIA study were divided into race/gender-specific quintiles for each nutrient and cross-tabulated. Results: For most nutrients, over 60% of those in the lowest absolute intake quintile at year 0 remained in the lowest or second-lowest quintile at year 7. A similar pattern was seen with highest absolute intake quintiles at years 0 and 7. Tracking was attenuated when nutrient density, rather than absolute intake, was examined. Conclusions: Ingrained dietary habits may cause high- or low-intake groups to retain relative ranking, even in the face of secular, age-, or lifestyle-related trends in dietary intake.