Adults tend to consume less pizza and soda when prices increase, and their body weight and overall calorie intake also appear to decrease, according to a report in yesterday’s edition of Archives of Internal Medicine.

“To compensate for food environments where healthful foods (i.e., fresh fruits and vegetables) tend to cost more, public health professionals and politicians have suggested that foods high in calories, saturated fat or added sugar be subject to added taxes and/or that healthier foods be subsidized,” the authors write as background information in the article. “Such manipulation of food prices has been a mainstay of global agricultural and food policy, used as a means to increase availability of animal foods and basic commodities, but it has not been readily used as a mechanism to promote public health and chronic disease prevention efforts.”

Between 1985 and 2005, a 10% price increase was associated with a 7% decrease in calories consumed from soda and a 12% decrease in calories consumed from pizza, according to lead researcher Kiyah J. Duffey, PhD, and colleagues at the University of North Carolina, Chapel Hill.

A $1 increase in the cost of soda or pizza was also associated with a lower overall daily calorie intake, lower body weight and improved insulin resistance score. A $1 increase in the cost of both soda and pizza was associated with even greater changes.

The researchers estimate an 18% tax on these foods would result in a decline of roughly 56 calories per person per day—the equivalent of 5 pounds per person per year—with corresponding reductions in the risk of obesity-related diseases.

“In conclusion, our findings suggest that national, state or local policies to alter the price of less healthful foods and beverages may be one possible mechanism for steering U.S. adults toward a more healthful diet,” the authors write. “While such policies will not solve the obesity epidemic in its entirety and may face considerable opposition from food manufacturers and sellers, they could prove an important strategy to address overconsumption, help reduce energy intake, and potentially aid in weight loss and reduced rates of diabetes among U.S. adults.”

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