The Mexican government implemented a 1 peso per liter tax to sugar-sweetened beverages (SSB) in 2014. Current evidence of its effectiveness has been mainly based on population purchase studies. This study aimed to examine the change in soft drink category of consumption in a cohort of Mexican adults, three years after the implementation of the tax.
We fitted, in an open –cohort sample, an ordered logistic correlated random effect regression using three waves of data from 2004 to 2018, from The Health Workers Cohort Study (HWCS). The HWCS is cohort of healthy employees and their families, from the Mexican Institute of Social Security, in Cuernavaca, Morelos Mexico. We included 3780 individuals >=19-years with at least one measurement of completed beverage section of the Food Frequency Questionnaire in the three waves. We estimated the change in the probability of belonging to one of four categories of soft drinks consumption after the tax was implemented. We also assessed the effect on the probability by income level.
Three years after implementation, we found that the SSBs tax was associated with a 6.8% and 6.2% decrease in the probability of being in the medium and high categories of soft drink consumption. In contrast, we observed an increase in probability of being in the low (8.3%) and never (4.7%) consumption categories. Individuals in the middle-income group showed the largest change in the probability of being in one of four categories of soft drink consumption compared to low- and high-income individuals. Their probability of being a low-consumer increased 9.5% and being a high soft drink consumer decreased 7.1%.
The Mexican SSB tax was associated with a sizable reduction in soft drinks consumption after three years of implementation. An increase tax to 20% could further reduce consumption. SSB taxation, together with other Mexican obesity prevention policies, has the potential to result in positive health outcomes and mitigate the increase in obesity.