The growing socioeconomic disparity in dietary quality: mind the gap.

Abstract

Disparity in dietary quality is a public health concern in the United States. Excess caloric intake induces obesity and diabetes mellitus, which in turn cause cardiovascular diseases. Similarly,poorerdietaryqualityhasbeenshowntoaffecthealth outcomes, whether directly or via intermediate chronic conditions such as hypertension and dyslipidemia. The link between lower socioeconomicstatus (SES)andunhealthfuldiet ismultifactorial.People of lower SES tend to have less access to healthful food; “food deserts”denote areaswhere residentsmayhavedifficulty getting nutritious food, mostly in poorer communities.1 Higher prices keep poorer people from buying more healthful food. Lower-SES individuals alsomayhave limitedknowledgeabout the effect of an unhealthful diet on their health. Federal and state governments have attempted to address the issueofdietarydisparitymostly through theSupplemental NutritionAssistance Program (SNAP, formerly known as theFoodStampProgram).2More than47million SNAPparticipants receivebenefits averaging$133perpersonpermonth (nearly $80 billion per year in total). Currently, there is neither any incentive tobuyhealthful foodnor restrictionof benefits for unhealthful food; households can use SNAP benefits tobuy“junk food”suchas softdrinks, candy, andpotatochips. This issue has provoked multiple debates in Congress and elsewhere.3-5 Several studies have investigated the effect of SNAPparticipationondietaryquality,but the resultshavebeen inconclusive. For example, the recently published study from theUSDepartmentofAgriculture (USDA)comparingSNAPparticipantsandnonparticipantsofequivalentSESusingdata from the National Health and Nutrition Examination Survey (NHANES) showed that SNAP participants had slightly lower overall Healthy Eating Index scores but also that SNAP participants consumed less saturated fat and sodium.6 Whereas these studies provided important information about individual-level associations of SNAP,wealsohaveneededbird’seye national-level evaluation ofwhether these governmental efforts have affected the nationwide temporal trend in dietary quality. In this context, the new study byWang et al7 successfully illustrates the trend from 1999 to 2010 in discrepancy of dietary quality by SES in the United States, using the Alternate Healthy Eating Index 2010 (AHEI-2010) to measure dietary quality by SES category, definedon thebasis of education and income level. Scoreson theAHEI-2010 improved for thepopulation as awhole, but the gap in scores (excluding the trans fat component, which was not measured in NHANES) between higher-SES and lower-SES groups widened during the observed period. The growing chasm indietary quality by SES confronts us with thepossibility that the governmental efforts tomind this gap have been insufficient. It is disappointing that the improvement seen in those of higher SES was not seen in the lower-SES group. How could we close the dietary quality gap? First, we could restrict benefits to more healthful foods, as has been done by the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), which restricts purchasable foods with the benefit. There have been proposals to adopt a pilot state-specific restriction on soft drinks. For example, New York state asked the federal government to waive SNAP rules to permit a pilot project excluding SNAP benefits for sugar-sweetened beverages in New York, New York, but the USDA denied this request for the reasons that “the scale and scope of the proposed demonstration is too large and complex”3 and that unresolved operational challenges could greatly affect the food retailers accepting SNAP benefits.3,4 Instead, the USDA conducted a large randomized controlled study, the Healthy Incentives Pilot (HIP), which provided financial incentives for more healthful foods (30 cents for every SNAP dollar spent on fruits or vegetables).8 Interim findings from the study suggest that HIP changed Related article page 1587 Trends in Dietary Quality Among US Adults Original Investigation Research