U.S. researchers said Thursday that raising the price of sugary soft drinks will likely prompt thirsty consumers to seek out cheaper, healthier beverages.

They said raising the price of a can of soda by 35 percent cut soft drink sales in a hospital cafeteria by 26 percent, offering some evidence that adding a tax to soda pop may prod consumers into making better choices.

Obesity adds an estimated $147 billion each year in costs to the U.S. health care system and several states have weighed a tax on sweetened soft drinks to defray the cost of obesity-related diseases.

“Obesity is at epidemic levels. It’s an incredibly difficult and complicated problem,” Dr. Jason Block of Harvard University in Boston, whose study appears in the American Journal of Public Health, told Reuters

He said soft drinks have been increasingly recognized as a major contributer to the rising obesity epidemic in America.

First Lady Michelle Obama unveiled a 70-point plan last month to reduce childhood obesity, which called for an analysis of the impact of local sales taxes on consumption of less healthy foods.

According to the American Heart Association, too much sugar not only makes people fatter, but is also a key culprit in diabetes, heart disease and stroke.

“Regular soft drinks make up about 7 percent of all calories consumed in the United States,” Block said in a telephone interview with Reuters, adding that they are a “major driver” of obesity in the United States.

Block and colleagues raised the prices of a can of soda by 45 cents, or 35 percent, in the cafeteria for the study at the Harvard-affiliated Brigham and Women’s Hospital in Boston and then measured the effect on sales.

The price increase applied to sugary soft drinks, which they defined as carbonated beverages with calories.

Block said “What we found is that a price increase of 35 percent on regular soda led to a 26 percent decline in regular soda sales.”

He said that instead of reaching for an energy drink or fruit juice, people tended to increase their consumption of diet drinks or coffee during the study period.

The team compared the effect of a price increase to an educational campaign, during which the team posted signs and information about weight loss and the need to cut back on sweetened beverages.

Block said that this appeared to have no effect on buying habits of regular soda.

He said the study suggests a price increase should be part of the conversation policymakers have among themselves as they try and determine their options to address obesity through the U.S.

“There are a number of proposals out there to levy taxes on soda. I think it’s an important discussion. We see from this study there is some evidence that it could work to reduce consumption rates,” Block told Reuters.

The America Beverage Association, which is a trade group that includes Coca-Cola Co., Pepsico Inc., and Dr. Pepper Snapple Group, said they strongly disagree with such taxes and says sugar-sweetened drinks are not a unique risk factor for obesity or heart disease.