The U.S. government should deal with unhealthy ingredients in food the same way it deals with pollution: with cap and trade, a suggestion published Thursday in The New England Journal of Medicine. In the imagined cap and trade policy, companies could manufacture products above a government-capped level of sugar and fat, but would be taxed for the additional unhealthiness at a cost passed on to the consumer.

The idea of government trying to regulate what people eat to improve public health, increase productivity, and reduce health care costs is not that farfetched. Denmark made headlines after implementing a fat tax, adding a premium to things like sugary soda.

Kristina Lewis, a doctor at Harvard Medical School's Department of Population, co-author of the report, recognizes that establishing such a policy would be an uphill battle. But she also believes something has to be done in the realm of public policy, because she said encouraging people to change their behavior is not enough.

The burden of chronic disease is huge, she said.

She and her colleague Meredith Rosenthal acknowledge in their article that regulating ingredients in food could be unfair to some businesses. Restaurants that sell fresh sandwiches and wraps would have to implement fewer changes than, say, places that sell fried chicken.

European countries have typically been more accepting of cap-and-trade policies, Lewis said, and it is possible that they would adopt such a food policy long before the U.S.

The policy change they suggest comes at a time experts are leaving no stone unturned in the quest for new ways to combat obesity, the complications of which contribute to more preventable deaths than smoking. An estimated 162,000 U.S. residents die annually from complications due to obesity such as cardiovascular disease and cancer, according to a 2007 report in the Journal of the American Medical Association.

Rosenthal and Lewis are not alone in their call for new food-related health policies. At a panel discussion in October at the Harvard School of Public Health, epidemiologist Walter Willett said the prevalence of red meat and processed starches in the American diet is contributing to alarming rates of obesity and even decreasing life expectancies in some areas.

If we judge by its impact on human health, the American food supply is a disaster, Willett told the Harvard Gazette. We're not using the levers we potentially have to make an impact.

Cap and trade policies have helped improve the quality of life in the U.S. by reducing acid rain and smog. But ingredients in food are not as straightforward as tailpipe emissions. We still need fat, salt and sugar.

The types of food people like further complicates the notion of a cap and trade plan. To force Americans to give up doughnuts, French fries and hamburgers would be impossible - we simply like these things too much, Rosenthal and Lewis wrote.