No one likes higher taxes, but a tax on junk food may be a necessary evil to help prod people who are overweight into shedding some of those unhealthy extra pounds.
A new U.S. study suggests that price is a powerful motivator when it comes to weight control. Of particular interest is the fact that fattening foods lose some of their appeal as they become more costly.
The findings, published this week in the journal Archives of Internal Medicine, are based on 5,115 adults whose dietary habits were charted for about two decades, from 1985 to 2006.
Prices for a variety of foods were compiled for the same time period.
With this information in hand, the researchers at the University of North Carolina at Chapel Hill created a statistical model to evaluate the effects of price swings on demand.
The results revealed a firm link between prices and the amount of calories consumed of certain foods.
For instance, a 10-per-cent price hike triggered a 7-per-cent dip in calories consumed from soft drinks and a 12-per-cent drop in calories consumed from pizza.
"This study gives us strong scientific evidence that price policies, including taxes, could actually be effective at helping control obesity and the resulting chronic diseases, like diabetes," the study's senior author Barry Popkin said in a release.
Various governments have been toying with the idea of imposing taxes on "unhealthy" foods, but such proposals have met with strong industry opposition.
Penny Gordon-Larsen, one of the study authors, acknowledged that it can be "difficult" to categorize specific foods as being inherently unhealthy.
After all, pizza "provides some nutritional value" so long as it isn't consumed all the time and is part of a balanced diet.
But, she said, sugar-sweetened soft drinks clearly fit the bill.
"It's easy to think of removing soda [from the diet]because it doesn't add any nutritional value."
Based on the study's projections, an 18-per-cent tax on just pop would result in a decline of roughly 56 calories per person per day in the United States.
Over a period of a year, that would translate into a reduction of five pounds (2 kilograms) per person. "We drink a lot of soda," she added.
In an accompanying editorial, Mitchell Katz and Rajiv Bhatia of the San Francisco Department of Public Health point out that governments often intervene in the food market - and some of those actions have actually contributed to the obesity epidemic. "Sadly, we are currently subsidizing the wrong things, including the production of corn, which makes the corn syrup in sweetened beverages so inexpensive," they write.