Where are the data?

While proponents of a new penny-per-ounce soda tax claimed this week that it could significantly reduce obesity and save $17 billion dollars in medical costs annually, ACSH doubts that such a tax would have any beneficial impact on public health at all.

A new report published in the journal Health Affairs used a wide variety of tenuous computer models and estimations to conclude that a penny-per-ounce soda tax would save thousands of lives. The authors assumed that such a tax on sugary beverages, including soda, punch, and sports drinks, would result in a 15 percent reduction in their consumption. They then made the questionable claim that about 40 percent of these soda calories would be replaced by a greater intake of milk and juice. Overall, they concluded that American adults would end up consuming nine fewer calories per day, which the authors claimed would reduce the number of obese adults by 867,000 over the course of 10 years. This decrease would supposedly result in health benefits that include preventing 2.6 percent of diabetes cases. In turn, they predict that the reduction in obesity and diabetes would prevent almost 100,000 cases of coronary heart disease and 26,000 premature deaths over the course of a decade.

But as ACSH's Dr. Gilbert Ross explains, This report has just about no basis in reality. The researchers began with a foregone conclusion and then tried to support that conclusion. The study is based on estimates and assumptions that were put into a computer model, which is not solid evidence of the real, behavioral effects of such a tax.

ACSH's Dr. Ruth Kava is similarly unimpressed with the report s conclusions. Their assumptions may or may not be true, she says. I strongly doubt that consuming just nine fewer calories per day would result in the staggering health benefits that they claim. And it s far from clear that people wouldn t just replace those fewer calories with other high-calorie foods. Even switching to juice wouldn t help prevent obesity juice is high in calories too.