Introduction: Unhealthful diet is one of the top contributors to the chronic disease burden in the U.S. There are growing concerns that socioeconomic disparities exist in Americans’ diets and this disparity may have widened over time.
Aim: To characterize trends in dietary intake of key food groups and nutrients among low-income Americans who participated in the Supplemental Nutrition Assistance Program (SNAP), and assess whether disparities in U.S. diets have persisted, improved, or worsened over time.
Methods: Nationally representative sample of 6,162 adults aged 20 years or older who participated in SNAP, 6,692 income-eligible nonparticipants, and 25,842 higher-income nonparticipants from 8 National Health and Nutrition Examination Survey (NHANES) cycles (1999-2014). Exposures are calendar year and SNAP participation status. Survey-weighted, energy-adjusted mean scores and proportion meeting the American Heart Association (AHA) 2020 Strategic Impact Diet Goals (5 primary components: fruits/vegetables, whole grains, fish/shellfish, sugar-sweetened beverages (SSBs), sodium; 3 secondary components: nuts/seeds/legumes, processed meats, saturated fat). Intakes of individual food groups and nutrients were also assessed.
Results: From 2003-2004 to 2013-2014 among SNAP participants with data on two-day dietary recall, primary diet score (maximum of 50) modestly increased (15.6 to 16.6; P-trend =0.03) while the secondary diet score (maximum of 80 points) did not change (31.5 to 32.1; P-trend =0.11). The proportion of SNAP participants having a poor diet decreased from 74.3% to 68.6%, the proportion having an intermediate-quality diet increased from 25.5% to 31.2%, and the proportion of having an ideal diet remained unchanged (0.2%.). Among primary components, changes were strongest for SSBs (-0.43 servings/d, P-trend=0.001) and whole grains (+0.25 servings/d, P-trend<0.001). Compared to higher-income nonparticipants and income-eligible
nonparticipants, SNAP participants had weaker improvements in both primary and secondary diet scores. From 1999-2000 to 2013-2014, disparities persisted for most dietary components, worsened for nuts/seeds and added sugars, and weakened for sodium.
Conclusion: Despite some improvements in diet quality, SNAP participants still fall far short of meeting the AHA Goals for a healthful diet, and dietary disparities persisted or worsened for most dietary components.