BACKGROUND
An unhealthy diet ranks among the top contributors to the burden of noncommunicable chronic disease and death in the US, highlighting the importance of evaluating diet quality in population-based studies, such as the MIDUS (Midlife in the United States) cohort.
OBJECTIVE
1) To develop a simple tool (MIDUS healthy eating index (MIDUS-HEI)) to evaluate diet quality more broadly and consistently in subjects enrolled at different time points of the MIDUS study, and 2) To use this score in assessing the cross-sectional association of the overall dietary pattern with sociodemographic and health variables in MIDUS participants.
METHODS
We used extant food intake data collected from participants in two biomarker sub-studies of the MIDUS Core and Refresher national samples to design, test, and validate the dietary score tool through its cross-sectional association with available sociodemographic and health variables.
RESULTS
Our results indicated that better dietary quality was observed among older adults as well as white subjects and those with a higher educational status. According to the MIDUS-HEI score, dietary quality improved over time in MIDUS Refresher cohort compared to the MIDUS Core cohort. However, race-based disparities in dietary quality increased between the two survey times. Regarding health variables, MIDUS-HEI score was inversely associated with the prevalence of metabolic syndrome (MetS) and most of its diagnostic criteria.
CONCLUSIONS
The MIDUS-HEI score is a useful indicator of quality of diet intake, exhibiting an inverse cross-sectional association with unhealthy diet-related biomarkers and MetS. Also, sociodemographic-dependent variations of this index were consistent with similar dietary pattern scores evident in other epidemiological studies. Thus, MIDUS-HEI represents a valuable tool for further analysis and discovery using the wide multidisciplinary scope of MIDUS.