SNAP Participant Diet Quality Still Poor

A new Food-PRICE study finds persistent nutritional disparities within the food choices of those receiving assistance under the Supplemental Nutrition Assistance Program (SNAP) compared with those not receiving SNAP assistance. The study is published in JAMA Network Open.

Led by researchers from the Friedman School of Nutrition Science and Policy at Tufts, the study examined the dietary patterns of SNAP recipients with two comparison groups, those whose income qualifies them for SNAP but choose not to participate, and those whose income is higher than the SNAP guidelines.

The study represents the characteristics of 25.5 million adult SNAP participants, 26.9 million income-eligible nonparticipants, and 158.7 million higher-income US adults. The team used data for US adults aged 20 years and older who had completed at least one valid 24-hour diet recall during eight two-year cycles of National Health and Examination Survey through 2014.

Based on the American Heart Association (AHA) 2020 Strategic Impact Goals for diet, the research team created a summary score reflecting a diet quality of poor, intermediate, or ideal. A poor diet corresponded to less than 40% adherence to the AHA 2020 goals, an intermediate diet to 40% to 79.9% adherence, and an ideal diet to 80% or greater adherence.

Greater consumption of fruits/vegetables, fish/shellfish, whole grains, and nuts/seeds/legumes, and lower consumption of sugary-sweetened beverages, sodium, processed meat, and saturated fat contributed to a better diet score.

For the 2003–2004 to 2013–2014 survey group, the average diet score among SNAP participants didn't significantly improve. During the same period, however, the average AHA diet score significantly improved in both income-eligible nonparticipants and higher-income individuals.

Dietary disparities worsened for several key food groups. Compared with both income-eligible nonparticipants and higher-income individuals SNAP participants experienced smaller reductions in added sugar intake, experienced no appreciable increases in intakes of nuts/seeds or fish/shellfish, and actually increased their intake of processed meats such as hot dogs, deli meats, and sausages.

"Over time, there were some improvements for certain food groups and nutrients among SNAP participants, such as increased consumption of whole grains, whole fruits, and dark green vegetables, and decreased consumption of sugary-sweetened beverages," says first author Fang Fang Zhang, MD, PhD, an epidemiologist and associate professor at the Friedman School at Tufts. "However, SNAP participants still had the lowest diet quality compared to income-eligible nonparticipants and higher-income individuals by 2013–2014. SNAP participants also had the lowest consumption of fruits and vegetables, whole grains, fish and shellfish, and nuts, seeds, and legumes, and the highest consumption of sugary-sweetened beverages."

"Disparities persisted for most food groups and nutrients. Even after adjusting for differences in age, sex, race/ethnicity, education, and income over time, diet-related disparities by SNAP participation status were not materially altered for most dietary components," says cofirst author Junxiu Liu, PhD, a postdoctoral scholar at the Friedman School at Tufts.

"These poor diets should not be interpreted as a cause-and-effect of participating in SNAP. It is possible that dietary trends of these low-income Americans could have been even worse without participation in SNAP," says Dariush Mozaffarian, MD, DrPH, dean of the Friedman School at Tufts.

The authors also found that the proportion of SNAP participants among US adults increased from 9% in 1999–2000 to 17% in 2013–2014, which could reflect changes in economic factors—in particular the economic recession during this period—and to a lesser extent changes in SNAP policies in the 2002 and 2008 Farm Bills that improved accessibility and expanded eligibility. These economic and policy changes moved individuals with greater education and previously higher income onto SNAP. Because such individuals would generally have better diet quality than participants in SNAP with less education, such population shifts likely make the observed dietary disparities by SNAP participation among US adults even smaller than they would be otherwise.

In the limitations portion of the study, the researchers noted that self-reported dietary intake is subject to measurement error, although they also note that it's an excellent method for estimating the mean intake of groups like in this study. They also note that SNAP participants may have different benefit levels over time, producing partial misclassification of SNAP participation.

This study is part of the Food Policy Review and Intervention Cost-Effectiveness research initiative, which focuses on population-level nutrition strategies and their relation to cardiovascular and cancer health outcomes.

— Source: Tufts University