February 21, 2017


Dr. Barry M. Popkin

A new study, published in Health Affairs and co-authored by researchers from the University of North Carolina at Chapel Hill’s Gillings School of Global Public Health and the Mexican Instituto Nacional de Salud Pública (National Institute of Public Health), has found that purchases of sugar-sweetened beverages (SSBs) declined further in the tax’s second year. The higher decline can be linked to the passage of Mexico’s landmark tax on SSBs in 2014 – the first national tax on SSBs as part of a nationwide effort to address a country’s obesity epidemic.

The Mexican government enacted the SSB tax after a 2012 study indicated that more than 70 percent of the country’s population was overweight or obese, and that in excess of 70 percent of the added sugar calories in the Mexican diet were coming from SSBs.

The study, titled “In Mexico, Evidence Of Sustained Consumer Response Two Years After Implementing A Sugar-Sweetened Beverage Tax,” found that in the two-year period spanning 2014 to 2015:

  • The one-peso-per-liter excise tax on sugar-sweetened beverages in Mexico resulted in a 5.5 percent reduction in the first year and continued to decline, averaging 9.7 percent the second year.
  • During the same period, purchases of untaxed beverages such as bottled water increased 2.1 percent.
  • Lower socioeconomic households, for whom health-care costs are most burdensome, also lowered their purchases of sweetened beverages the most.
Dr. Shu Wen Ng

Dr. Shu Wen Ng (Photo by Elisabeth Delafield)

The findings run counter to initial reports from the sugar-sweetened soda industry, which said that the purchases of SSBs actually went up after the initial tax year. However, the researchers found those reports did not account for numerous significant factors, including inflation and shifts in population.

“After adjusting for these and other factors, we found that, despite industry claims to the contrary, there was actually an additional 4 percent decline in sugar-sweetened beverage purchases per capita in the second year of the tax,” said the study’s corresponding author Shu Wen Ng, PhD, associate professor in the Department of Nutrition at UNC’s Gillings School of Global Public Health.

International agencies such as the World Health Organization, the Pan American Health Organization and many others have pointed to the link between consuming added sugar products in daily diet and increases in overweight and obesity in countries across the world.

“Using a modest tax to discourage consuming SSBs in Mexico is having an effect in reducing purchases during these initial years of its implementation. It will be important for us to continue to monitor this tax and see how this actually will affect overall diets, diabetes prevalence and other biological markers of the many noncommunicable diseases linked with excessive sugary beverage consumption,” said Barry M. Popkin PhD, W. R. Kenan Jr. Distinguished Professor of nutrition at the Gillings School and co-author of the paper.

Mike Bloomberg, three-term New York City Mayor and current World Health Organization Global Ambassador for Noncommunicable Diseases, said the study presents conclusive evidence that the tax is effective.

“The results couldn’t be clearer: Mexico’s tax on sugary drinks is working,” Bloomberg said. “That’s great news for the country’s health, and it adds momentum to the growing push for similar policies in cities and countries around the world. It’s one of the best steps governments can take to fight the rising obesity epidemic.”

“Reductions in consumption will yield long-term health benefits in terms of reduced diabetes and mortality,” said Juan A. Rivera, general director at the Instituto Nacional de Salud Pública and a co-author of the paper. “Another study in PLOS Medicine that used findings from only the first year of the tax found that the tax will lower the incidence of Type 2 diabetes cases in Mexico by 200,000. If the PLOS Medicine study had used the higher two-year reduction in purchases of sugary beverages in their modeling, it would find more impressive reductions in Type 2 diabetes cases.”

Arantxa Colchero, PhD, associate professor in the Center for Health Systems Research at the Instituto Nacional de Salud Público and first author of the paper, noted that some families can take advantage of certain economic benefits from the change in consumption.

“Lower-income households reduced their consumption of sugary beverages the most in both years of the tax, reducing their purchases by 9 percent in 2014 and 14.3 percent in 2015,” Colchero said. “This means that they are able to transfer the savings from lowering purchases of these unhealthy beverages toward other purposes.”

The full study can be found in Health Affairs. The study was supported primarily by Bloomberg Philanthropies, with additional support from the National Institutes of Health and the Robert Wood Johnson Foundation.


Gillings School of Global Public Health contact: David Pesci, director of communications, (919) 962-2600 or dpesci@unc.edu

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