Walmart's packaged foods have become healthier, study finds; income, race still major predictors of food choices

October 27, 2015

The nutritional quality of packaged food at Walmart has improved since 2000, according to a new study by UNC Gillings School of Global Public Health researchers. That should be good news, given that Walmart and other major retail chains are the biggest sellers of foods purchased and eaten by U.S. consumers.

Dr. Lindsey Smith Taillie

The study, led by Lindsey Smith Taillie, PhD, UNC Gillings School of Global Public Health alumna and research assistant professor of nutrition at the School, was published online Oct. 21 in the American Journal of Preventive Medicine. Taillie is also a fellow at UNC’s Carolina Population Center.

Using data collected from the Nielsen Homescan and Nutrition Facts Panel on more than 164,000 shoppers, Taillie and colleagues examined changes in nutrient quality and key food groups purchased at Walmart and other food retail chains, such as grocery stores, supermarkets and supercenters, between 2000 and 2013. They also considered whether these changes differed for low-income or minority households.

The study determined that, during this period, foods sold at Walmart declined in calories (73 fewer per 100 grams), in sugar (8 grams fewer per 100 grams) and in sodium (33 mg. less, per 100 grams). There also was a decrease in households’ percentage of volume purchased from sweets (down, 11 percent), grain-based desserts (down 2 percent) and savory snacks (down 3 percent), and increases in purchases of fruits (up, 3 percent) and vegetables (up, 1 percent).

Other food retail chains had more favorable nutritional profiles than did Walmart in 2000, but they demonstrated smaller improvements over time. By the end of 2013, Walmart and other food retail chains were very similar with regard to the nutritional profile of purchases made there.

The study also showed that low-income households did not buy disproportionately fewer healthy foods at Walmart, although they did buy less healthy food at other food retail chains. Black households had the worst nutritional profile of purchases at Walmart and at other food retail chains, and this persisted over time.

“Once we control for the types of people who shop at a certain food store,” Taillie said, “there is no meaningful difference between the nutritional quality of foods purchased at Walmart, as compared to other major chain retailers where people shop for food. What is of concern is that both at Walmart and other food retail chains, the nutritional quality of food purchases made by non-Hispanic blacks was the lowest.”

Taillie said more research was needed to understand and address diet-related disparities in low-income and black households.

“It appears that the type of retailer where food is purchased is less important than other underlying characteristics that influence the healthfulness of food purchases,” she said. “Low-income and black households are especially at risk to have low-nutrient profiles of purchases, and more work is needed to understand how to improve the nutritional quality of the foods they buy and eat.”

Walmart, the authors noted, is now the largest food store, with $117.4 billion in grocery sales in 2013, more than $40 billion more than its nearest competitor, Kroger.

Co-authors of the study were Shu Wen Ng, PhD, research assistant professor, and Barry Popkin, PhD, W.R. Kenan Jr. Distinguished Professor, both in the Gillings School’s Department of Nutrition and both fellows at the Carolina Population Center.