Recent Dissertations: Tiffany Stallings (Epidemiology) studies fruit and vegetable intake among low-income U.S. women

March 6, 2013 - Every month, millions of Americans rely on the United States Department of Agriculture’s Food and Nutrition Service Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) to put food on the table for their families.  WIC strives to combat nutrition deficiencies among medically at-risk young children and low-income women who are pregnant or breastfeeding. The need is acute: of the over 9 million WIC recipients in 2010, some 2.17 million were infants, and WIC serves over 50% of all infants born nationwide. 

For Emory PhD Tiffany Stallings, ensuring the nutritional health and improving the dietary habits of WIC recipients is imperative. “The consumption of fruits and vegetables is below recommended amounts in the United States,” Tiffany observes, “and generally lower low-income individuals eat less fruit and vegetables than others.”  Tiffany explored how to alleviate this predicament by joining the Emory WIC Farmers' Market Nutrition Program (FMNP) Study currently being led by her advisor, Dr. Julie Gazmararian. Tiffany’s dissertation, Influential Factors in Fruit and Vegetable Consumption Among Low-Income U.S. Women, combines multiple analyses of the factors influencing fruit and vegetable consumption and the nutrition environment among low-income women.

The Meaning of Nutrition

It’s hard to underestimate the role of nutrition for a healthy lifestyle. For Tiffany, the issue is personal. “At a young age, my father suffered a fatal heart attack and thus began my awareness of the importance of a healthy diet,” Tiffany explains. “During my educational career, I sought courses that increased my knowledge of nutrition and taught me about the impact of diet on health.”

Tiffany’s quest to understand the role of nutrition in personal health led her to investigate some of the cutting-edge research on the topic currently underway at Emory. “When it came time to decide on a dissertation topic, I was excited to learn about Dr. Gazmararian’s study, the Emory WIC FMNP Study, which examined the change in fruit and vegetable intake among WIC recipients following the farmers’ market experience. Since F&V consumption is generally lower among low-income individuals and those of minority racial and ethnic groups, this project motivated me to seek an understanding of factors associated with eating fruit among the WIC population.”

Working with Dr. Gazmararian, Tiffany combined data from multiple studies into a complex analysis. Her two primary data sources were Dr. Gazmararian’s Emory WIC Farmers' Market Nutrition Program (FMNP) Study and the USDA’s Infant Feeding Practice Study II (IFPS II). The IFPS II gathers information from mothers using a series of questionnaires administered from the woman's seventh month of pregnancy through the infant's first year of life, and tracks maternal diets during pregnancy and after giving birth, infant nutrition, child care arrangements and more. Tiffany combined IFPS II data with Dr. Gazmarian’s findings on how WIC recipients use their Electronic Benefit Transfer (EBT) cards while purchasing fruit and vegetables at Farmers Markets in order to understand the availability, quality, and affordability of food options available to WIC recipients. 

Figure 1 describes the total fruit and vegetable intake of mother and child by FMNP group (non-FMNP, FMNP, and FMNP who used all their coupons) for all three surveys (baseline, 1-week and 4-week follow-up).  This data led Tiffany to conclude that the requirement to use all FMNP coupons on the day they are issued may result in higher fruit and vegetable intake.  The graph shows that for both the mother and child, there was an increasing trend (non-significant) across survey time points in intake for those FMNP participants who used all of their coupons. 

Framing the Findings

“Previous research has indicated that WIC recipients ate more fruit than non-WIC recipients with similar incomes,” says Tiffany. Her dissertation analysis confirmed that non-WIC recipients did eat less fruit and vegetables. In addition, Tiffany discovered that before birth, vegetable consumption varied by WIC status, and that, after birth, breastfeeding women ate more fruits and vegetables than n0n-breastfeeding women.

Tiffany also found a significant difference in prenatal vegetable intake among WIC recipient categories and poverty status groups, with WIC recipients tending eat more fruits and vegetables than the other WIC/poverty status groups. For Tiffany, this data can directly shape policy, supporting increased efforts to inform non-WIC recipients that they may meet remaining eligibility requirements for WIC benefits. Tiffany adds ”The Emory WIC FMNP study results could also support WIC-led nutrition education programs to teach nutrition competencies and the nutrition environment.”

Figure 2 shows the prenatal and postnatal median fruit and vegetable intake among IFPS II participants who completed at least one dietary history questionnaire by WIC/poverty status. Respondent categories were WIC recipients who financially qualified for WIC (“low-income”), non-WIC recipients who financially qualified for WIC (“low-income), and those who didn’t financially qualify for WIC (“high-income”). 

Fostering Health from Emory to Beyond

Tiffany reflects on her time at Emory as being formative to her growth as a researcher and public health professional. She is particularly grateful to her advisor, noting that “Dr. Gazmararian quickly integrated me into her study team and I was grateful to experience every stage of research from study design and questionnaire development to data collection and entry to analysis and presentation of results.” Tiffany adds, “through coursework and my dissertation I have gained a wealth of knowledge and experience needed to continue focusing on nutrition as a way of improving the public’s health.”

If recent events are any indication, Tiffany’s commitment to improving the health of mothers and infants only grows stronger – she has just begun a new position as a Research Associate in Obstetrics and Gynecology at Texas Tech University Health Science Center in El Paso, Texas. 

Written by Patrick Blanchfield, PhD Candidate in Comparative Literature and a graduate assistant in the Laney Graduate School. 

Learn More

Doctoral program in Epidemiology

ETD entry for Stallings dissertation

Dr. Julie Gazmarian faculty webpage

Stallings, Tiffany L. “Association of Alzheimer's Disease and Chlamydophila Pneumoniae.” The Journal of infection 56.6 (2008): 423–31.

United States Department of Agriculture Food and Nutrition Program for Women, Infants, and Children (WIC) Program

WIC Farmers’ Market Nutrition Program 


Texas Tech University Health Science Center in El Paso

It Caught the Dean's Eye...

Dean Lisa Tedesco reviews every dissertation submitted to the Laney Graduate School. Usually, that means reviewing signature sheets and title pages, the abstract, a bit of the introduction, and perhaps something else. But some dissertations seize her attention, and she ends up reading a good deal more than that. This is the third in a series profiling some of those dissertations.