New York City Mayor Michael Bloomberg is raising an important issue that should lead to changes in the federal food stamp program.

Bloomberg is proposing a two-year trial in which the federal Food and Drug Administration would prohibit the 2.7 million food stamp recipients in New York from buying soda or other sweetened drinks with their taxpayer-funded debit cards. Behind Bloomberg's request is the idea that reducing the consumption of these sugary products will improve the health of food stamp recipients, leading to less obesity. His plan is to study results after the two-year trial.

Bloomberg's request raises the question of whether Coke, Pepsi and the other sugary drinks are food.

Food stamp users are restricted from buying cigarettes, alcohol, nonfood items such as pet food or paper products and vitamins. Prepared foods, such as the popular rotisserie chickens found in many grocery stores, also are prohibited.

Is it logical that using food stamps to buy a cooked chicken is not allowed, but buying a case of Pepsi or a bag of cheese curls is fine?

Bloomberg's request should stimulate a full review of the food stamp program.

If soda and sugary drinks contribute to the obesity crisis in America, which can lead to diabetes and all the expenses and terrible consequences of that chronic disease, should taxpayers be subsidizing those products for millions of low-income Americans?

Granted, drawing lines and deciding which healthy foods are allowable and which junk foods are not would be difficult. But, that doesn't mean that the food stamp program should not be changed.

The current program appears to be designed more for the benefit of giant food and beverage companies than to benefit low-income families and their health.

An alternative approach to a ban on unhealthy foods would provide vouchers for healthier drinks and foods, particularly fruits and vegetables. But a ban still is a reasonable move.

If asked in person by a low-income mother for help to pay her grocery bill, most Americans would walk her through the grocery store aisles, selecting healthier foods, including fresh vegetables, fruits and milk — not bags of candy or soda, which is not much more than colored sugar water. So, if food stamps are the large-scale version of that personal assistance, why should such unhealthy products be allowed?

Few people would argue that cigarettes and alcohol are food, or essential to a healthy diet. And, most people understand why those are not allowable food-stamp purchases. Who would argue that soda, with the equivalent of 10 packets of sugar in a 12-ounce container, is healthy food and an essential part of a proper diet?

Health officials note that consumption of soda and sugary drinks has more than doubled over the past 30 years. During that same period, obesity rates have jumped dramatically — as has the incidence of diabetes. Is this coincidental? Few people outside those in the soda and junk food industry say so.

And statistics also show that obesity and diabetes are more common in lower-income areas where food stamps are used by a larger percentage of the population.

These facts cannot be ignored. Soda, sugary drinks and junk food cannot be considered food. They are what one food writer calls "food-like substances." The sale of these products should not be subsidized by taxpayers. Doing so only increases the likelihood of obesity and other major health issues among lower-income Americans, which will, in turn, lead to higher Medicare costs for the treatment of heart disease, diabetes and other ailments associated with obesity.

The FDA should approve Bloomberg's proposal — and the ban should be expanded across the country, because obesity is a nationwide problem, not just a New York City problem.