March 9/Washington/Hindustan Times -- Unhealthy food and drinks such as pizzas and soda become less popular with increasing costs, suggests new research.

The study appeared in the March 8 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

The authors write as background information in the article, "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.

"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."

Kiyah J. Duffey of the University of North Carolina at Chapel Hill, and colleagues examined the dietary habits of 5,115 young adults, aged 18-30, beginning in 1985-86 and continuing through 2005-06. Food price data were compiled for the same timeframe. The height, weight and blood levels of glucose and insulin of the volunteers were also collected and a measure of insulin sensitivity was calculated.

Over the 20-year period, a 10% increase in price was associated with a 7% decrease in the amount of calories consumed from soda and a 12% decrease in the amount of calories consumed from pizza. A one-dollar increase in the cost of soda or pizza was also associated with a lower overall daily calorie intake, lower body weight and an improved insulin resistance score, and a one-dollar increase in the cost of both soda and pizza was associated with even greater changes in these measures.

The researchers estimate that an 18% tax on these foods would result in a decline of roughly 56 calories per person per day. They note that these declines would amount to weight loss of approximately five pounds per person per year, with corresponding reductions in the risk of obesity-related diseases.

They write, "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.

"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."

From the March 15, 2010, Prepared Foods E-dition