Soda tax wouldn’t work as obese people prefer diet drinks, study suggests

By Caroline Scott-Thomas

- Last updated on GMT

Related tags Obesity

A tax on sugar-sweetened beverages may not work to reduce obesity – because obese people could have a stronger tendency to buy diet soda, suggests new research from Northwestern University.

Ketan Patel, a fourth-year doctoral student in economics, recently presented his paper "The Effectiveness of Food Taxes at Affecting Consumption in the Obese: Evaluating Soda Taxes"​ at a US Department of Agriculture conference on food policy in Washington, D.C. He told FoodNavigator-USA that he had originally been interested in whether obese people were less price sensitive than those of normal weight – but the data suggesting greater preference for diet soda came as a surprise.

“I did find that obese consumers are less price sensitive, but that is completely overshadowed by their preference for diet soda,”​ he said.

Patel said he used a combination of store-level sales data from market research organization Nielsen, which provided information on location and sales of soft drinks and their relation to price, alongside 2002 to 2006 data from the CDC’s Behavioral Risk Factor Surveillance System (BRFSS). The CDC data included information on height, weight, income and diabetes status across 230 counties, representing 40 to 50 percent of the US adult population.

This data allowed Patel to estimate consumer preferences while allowing for ‘substantial diversity’ in those preferences. He then simulated how a tax would affect choices and used those results to estimate weight change, using an existing weight change model.

"After doing the analysis, it really turns out to be the case that obese people like diet soda so much more than regular soda that you can do whatever you want to the price,"​ he said. "You're not going to get that much change in obese people's weight because they already drink diet soda."

Patel said he was prompted to conduct the research after finding little research into whether obese people will respond to soda tax with changes in behavior. However, he acknowledged that a tax on sugary drinks could play a role in preventing obesity in normal weight or overweight people if they are gradually gaining weight over time.

“More research needs to be done on this aspect, however,”​ Patel said.

The idea of a soda tax has been repeatedly raised as a possible way to combat obesity while raising tax revenue. Meanwhile, its opponents say that the beverage industry is being unfairly targeted – and some, like Patel, question whether it would be an effective tool for tackling obesity anyway.

The poll accompanying this story is now closed. You can view the results here​.

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Posted by Jenny Jones, RD,

Diet soda is related to obesity, too. A 1 cent per ounce soda tax would allow California to raise over $1 billion a year to go towards obesity prevention efforts and would save $50 billion in health care costs over 10 years.

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Sugar v obesity

Posted by P D C Rogers,

No amount of nannying will stop obesity, as it is simply due to eating too much. If the consumer chooses to eat sugary foods onthe go, this will simply make things worse, quicker. Stop grazing and eat no more than three meals a day, and most obesity would be stopped.

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Unhealthy Food Taxes May Help

Posted by,

While increasing tax on sugar-laden sodas may not directly affect many of the current obese population, it could generate funds to increase weight management programs that could make a difference in the obese population - as well as fund nutrition education classes for children (paid-for summer nutrition camps would be a great start since the academic school year seems to refuse adding extra courses that are not geared towards national testing).

I know "Mom of Two" would like the government to get out of her grocery cart and let be become responsible - but the reality is that people are NOT responsible and unfortunately need some prodding to keep them from harming themselves and driving up healthcare costs for the entire population. Why shouldn't sugar-concentrated drinks NOT be demonized?
Who invented these syrupy concoctions that have become so easy for our children to "Biggie Size" and "Big Gulp" their way into hundreds of empty calories within just a few minutes (and then go back for a free refill)? I agree that it is calories in vs. calories out that determines weight gain/loss - but let's not make it so easy to tilt this thermal scale in favor of obesity.

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