Does A Sugar Tax Work? (New Study)

A new study published in JAMA looked at how a sugar tax affected BMI in US Cities.

In 2015, Berkley instituted a tax on sugar-sweetened beverages (SSB), while other cities in California, e.g. Albany, Oakland, and San Francisco, did the same in 2017. The tax was 1 cent per ounce of sugar-sweetened beverage. As a result, beverage cost went up by ~ a dollar and beverage consumption went down by ~ a third within 2 years of the tax being implemented. The tax may have had the largest effect in Berkley, as it decreased SSB consumption by over 50%.

In this study, trends in BMI were compared between cities implementing the SSB tax and nearby cities who didn’t. Data from over a million subjects were obtained through Kaiser Permanente medical records.

In the groups who consumed the most SSB, e.g. adults 20-39, BMI reduction was greater in cities implementing a SSB tax (- 0.3) compared to cities that didn’t (-0.13). In Berkley, where the reduction in SSB intake was the greatest, BMI reduction was also greater when compared to cities that didn’t. The impact of the tax is rather small, on average.

That said, across ALL cities implementing a SSB tax, the average change in BMI was about the same as cities that didn’t. Still, those groups having the highest SSB intake prior to the tax seemed to have the biggest “benefit” from the tax, as the tax did seem to drive a change in consumption.

Overall, I think the SSB tax is a reasonable policy to try in areas with high consumption. Is it universally a slam dunk? No, but I do think it can work in some areas, along with other supportive policy changes.

If they only accounted for obese people with actually high SSB consumption the effect size may have been much bigger.

Yes, I agree and the findings in Berkley and the highest consumers seem to support that notion. However, the researchers didn’t slice the data up for us to know for sure.