Improving Diet Quality in U.S. Adults: A 30-Year Health and Economic Impact Microsimulation.

Introduction: Epidemiologic studies relating health outcomes to dietary patterns captured by diet quality indices have shown better quality scores associated with lower mortality and chronic disease incidence. However, changing chronic disease risk factors only alters population health over time, and initial diet quality systematically varies across the population by sociodemographic status. This study uses microsimulation to examine 30-year impacts of improved diet quality by sociodemographic group.

Methods: Diet quality across 12 sex-, race/ethnicity-, and education-defined subgroups was estimated from the 2011-2012 National Health and Nutrition Examination Survey. In 2021, the Future Adults (dynamic microsimulation) Model was used to simulate population health and economic outcomes over 30 years for these subgroups and all adults. The modeled pathway was through lowering risk for heart disease by following U.S. Dietary Guidelines.

Results: Diet quality varied across the sociodemographic subgroups, and half of U.S. adults had diet quality that would be classified as poor. Improving U.S. diet quality to that reported for the top 20% in 2 large health professionals' samples could reduce incidence of heart disease by 9.9% (7.6%-13.8% across the 12 sociodemographic groups) after 30 years. Year 30 would also have 37,000 fewer deaths, 694,000 more quality-adjusted life years, and healthcare cost savings of $59.6 billion (2019 U.S. dollars).

Conclusions: Dynamic microsimulation enables predictions of socially important outcomes of prevention efforts, most of which are many years in the future and beyond the scope of trials. This paper estimates the 30-year population health and economic impact of poor diet quality by sociodemographic group.