The Dynamic Effect of SNAP Participation on Food Choices, Tobacco Use, and Health Outcomes Among Low-Income People

Year: 2012

Research Center: Institute for Research on Poverty, University of Wisconsin-Madison

Investigator: Yang, Zhou

Institution: Emory University

Project Contact:
Zhou Yang, Ph.D.
Emory University
1518 Clifton Road, NE
Atlanta, GA 30322
Phone: 404-727-3416


Food insecurity and malnutrition are two major public-health crises that pose health threats to low-income families in the United States. The Supplemental Nutrition Assistance Program (SNAP) is “the first line of defense against hunger and cornerstone of all Federal nutrition assistance programs,” according to the U.S. Department of Agriculture’s Food and Nutrition Service, which administers the program nationally in partnership with State and local governments. Due, in part, to the 2007-09 economic recession and high unemployment rate, SNAP accounted for 68 percent of the 2008 Farm Act budget, providing assistance to 47 million participants. Without significant improvement in the economy and job market, SNAP participation will most likely remain high.

The puzzling correlation between SNAP participation, obesity, and malnutrition in recent decades has triggered debate regarding whether SNAP needs reform to fulfill its original mission to improve the nutritional and health outcomes of both adults and children at risk of food insecurity. The current SNAP follows the policy structure designed in the 1960s as a “defined contribution” program through which the Federal Government provides nutrition assistance to low-income households to reduce hunger and improve health and well-being. However, the coexistence of high rates of obesity, malnutrition, and tobacco use among SNAP participants has led to questions about SNAP fulfilling its original mission when lifestyle and food environments have changed significantly since the 1960s. It remains uncertain whether and how SNAP leads to increased consumption of nutritious foods and better health outcomes or, on the contrary, if SNAP acts to increase the consumption of “sinful goods,” such as foods with high sugar or fat content and tobacco products, as consumers utilize existing household budgets for these items.

This study was conducted to investigate (1) the effect of SNAP on food choices and tobacco use, and (2) the subsequent effect of these food and tobacco consumption choices on health outcomes.

Secondary data analysis was conducted using the 2007 to 2008 waves of the National Health and Nutrition Examination Survey (NHANES). A simultaneous dynamic model was constructed to estimate the effect of SNAP participation on daily calorie intake; specific nutrient intake including carbohydrates, protein, sugar, fiber, and fat; daily cigarette consumption; the Healthy Eating Index of 2005 (HEI2005); as well as the subsequent health outcomes measured by clinical indicators of high blood sugar (HbA1c>7.0 percent), high blood pressure (BP>140/90mmHg), high cholesterol level (total cholesterol>240, or LDL>160, or HDL <40), and depression (a score of 15 or higher from the screening using Patient Health Questionnaire 9th Edition [PHQ-9]). Discrete random factor effect (DRFE) was used to control for unobserved individual heterogeneity that could influence not only SNAP participation, but also food choices, and health outcomes.

The results suggest that SNAP does not completely fulfill its mission to improve the nutritional and health outcomes of the low-income population in the current economy and food environment. After controlling for the unobserved heterogeneity and the major observed confounders such as demographics, educational level, and family size, this study tested the dynamic model with DRFE among different samples in different income levels. The results showed that SNAP participants had a lower calorie intake and worse quality of diet than the nonparticipants. Specifically, SNAP participants compared with SNAP non-participants had a 50 to 80 calorie lower daily caloric intake; 2.3 to 2.6 gram lower daily protein intake; 1.3 to 1.8 gram lower daily fiber intake; and 1.47 to 1.87 lower score of HEI2005.

In addition, the results from health outcome estimates showed that calorie intake, protein intake, fiber intake, and HEI2005 were the strongest predictors of better health in terms of lower probability of high blood sugar, high cholesterol level, and depression. The summarized results from both parts of the estimation showed that the net influence of SNAP on health outcomes was slightly negative, but was statistically significant.

There was no evidence from this investigation to suggest that SNAP leads to higher consumption of sugar, fat, or tobacco.