The study looks only at calories in food. The research does not make any claims about lowering obesity.

The United States' obesity rate has many factors, and the amount of calories consumed is only one, say the economists.

"We are not looking at health aspects," said Jensen. "Just the consumption of calories from sweetened goods and the disruption to the consumer."

The findings of the study fit generally accepted economic principles that say if you want to change a given behavior or economic decision, you should try to find a policy instrument that is closest to the behavior or decision, according to Beghin.

As part of the study, the two collected data from both government and private sources on industrial food inputs.

"We spent quite a bit of time assembling a data set based on published data on what inputs the food industry uses," said Jensen. "So we know that for all the different food sectors, how much sugar and corn syrup go into that industry group's food processing. You'd be amazed to see how much sweetener goes into food processing."

Disclosure: Beghin has been a consultant on sugar matters for the U.S. Government Accountability Office (2001), the Sweetener Users Association (2011), the American Enterprise Institute (2007), and the American Farm Bureau Federation (2004-5).