With so many studies linking Americans' collective sweet tooth to diseases including type 2 diabetes, heart disease and obesity, there's a lot of talk about policies to nudge consumers to consume less sugar.
A new study published in the American Journal of Agricultural Economics concludes that a tax on sodas and other sugary beverages could be the way to go. Specifically, the authors argue that taxing by the calorie would prompt consumers to cut back.
The authors calculated that a .04 cent per calorie tax — equivalent to a 6-cent tax per 12-ounce can of Coke or Pepsi — would lead consumers to consume about 5,800 fewer calories from sugary drinks per year.
"It seems quite intuitive," says study author Chen Zhen, a food and nutrition policy research economist at the Research Triangle Institute. Taxing calories directly, he finds, would lead people to purchase lower-calorie drinks. At least, that's what his modeling shows.
He and his colleagues used supermarket sales data to understand how price fluctuations influence consumer purchases. Then they modeled how various forms of taxing would change decision making. The studied was funded by a grant from the Robert Wood Johnson Foundation and the National Institutes of Health.
So, any chance of soda taxes becoming law? If past efforts are any indication, there are some pretty major hurdles.
As we've reported, a tax proposal in Massachusetts that would have extended the state's 6.5-percent sales tax to include candy and sugary drinks failed to get traction. And an effort in Florida in 2012 that would have restricted the use of food stamps to buy sugary treats and junk food failed, too.
The convenience store industry lobbied hard against the Florida measure. And the American Beverage Association has been a vocal opponent of measures that target sugary drinks.
"Taxes don't make people healthy," the ABA's Chris Gindlesperger told us when we were reporting on the debate over these efforts.
But this doesn't mean that policymakers won't try again. And, as more Americans become aware of the link between heavy sugar consumption and health risks, public health advocates say there may be more public support for such measures.
A recent Field Poll found 74 percent of California voters support efforts that would warn consumers about the potential harms of sugary drinks.
And last week, the California Senate passed the Sugar-Sweetened Beverage Safety Warning Act, that would mandate a warning label on the front of all bottles and cans of sugary drinks sold in the state that contain 75 calories or more per 12 fluid ounces.
It would read:
"SB 1000 [the act] supports consumers' right to know the facts about diabetes, undiluted by beverage industry spin," wrote Dr. Harold Goldstein of the California Center for Public Health Advocacy, which is a co-sponsor of the bill along with the California Medical Association, the Latino Coalition for a Healthy California and the California Black Health Network.
The group wants consumers to understand that when excess sugar enters the bloodstream "it overloads the pancreas and causes the liver to store the sugar as fat." Over time, this can increase the risk of fatty liver disease and type 2 diabetes.
Policymakers in the U.S. are not alone in their efforts to warn consumers about sugar. "France, Hungary, Finland and Mexico are all targeting sugar through various interventions," Simon Capewell, a professor of epidemiology at the University of Liverpool, tells us by email. Capewell authored a recent commentary in the British Medical Journal in which he argued in favor of warning labels.
"Many other potentially harmful products already carry effective health warnings," like insecticides and cigarettes, Capewell wrote. "Cigarettes have gone from being socially acceptable to quite unacceptable after warning labels were implemented."