Americans like their soda pop. And their sports drinks, and energy drinks, and sweet tea.
In 2021, the average American bought 37 gallons of sugar-sweetened beverages. Collectively, we consume about 145,000 calories per day from these drinks.
That level of consumption and its link to chronic diet-related diseases such as diabetes has become a major public health focus.
Now, scientists at the Fralin Biomedical Research Institute at VTC created a first-of-its-kind online marketplace to test how government policies might reduce sugar-sweetened beverage consumption.
A proof-of-concept study describes the Experimental Beverage Marketplace in a recent article in the journal Appetite.
“This tool provides a great opportunity to systematically test the potential effects of these tax proposals on purchasing and consumption,” said Assistant Professor Jeff Stein, interim co-director of the research institute’s Center for Health Behaviors Research and the study’s corresponding author. “It’s an important way to provide a base of evidence to inform taxes or other food policy to ensure that policy is guided by evidence and likely to have the effects we anticipate.”
Researchers tested the marketplace with 73 participants recruited online. Participants qualified for the study if they regularly bought sugar-sweetened drinks, were not on a diet, and were their household’s primary grocery shopper.
With a tax applied, participants purchased significantly less of sugar-sweetened drinks as measured by fluid ounces, number of items, and calories.
“In general, whatever you tax, people will buy less,” said Haylee Downey, a doctoral candidate in Virginia Tech’s Translational Biology, Medicine, and Health Graduate Program and the paper’s first author. “That’s a pretty standard economic concept, and we were able to replicate that with this tool.”
Other researchers have developed small, brick-and-mortar experimental stores for similar studies, but those are costly and can’t replicate the scale of a typical grocery store. Likewise, conducting large-scale studies with those methods is far more challenging. The virtual marketplace makes it easier to have a wide selection of products and to conduct studies with large sample sizes.
Downey and Stein designed the online beverage market to include hundreds of beverage options, from single servings to large multipacks, in a familiar online shopping interface. It builds on the Experimental Tobacco Marketplace, also developed at the Fralin Biomedical Research Institute.
Nearly all of the study participants who used the tool reported that it was easy to work with.
Several U.S. localities — including Philadelphia and Boulder, Colorado — already tax sugar-sweetened beverages, but tax rates and which products are taxed vary.
The online marketplace could help governments test proposed policies to assess their likely impacts — and identify potential unintended effects.
“What we’re focused on now is, what are people substituting with?” said Stein, who also has an appointment in Virginia Tech’s Department of Human Nutrition, Foods, and Exercise. “A tax can reduce consumption of these beverages, but where does that consumption go? Are they switching to a healthier pattern of consumption, or purchasing fewer beverages entirely, or substituting a different product altogether, such as a high-sugar cereal?”
The tool will require modification to answer those questions. Downey is continuing to develop the marketplace for a second, larger study central to her doctoral dissertation.
“I think it’s great that she’s continuing to move our lab forward with this,” Stein said. “I think this is going to be a tool that we continue to use even after Haylee graduates.”
By Matt Chittum