Last fall, New York Mayor Michael R. Bloomberg asked the U.S. Department of Agriculture to cut soda and other sugar- and corn-sweetened drinks from the list of “foods” that New Yorkers can buy with federal food-stamp benefits. Lobbyists, from soda makers to grocery stores to minority advocates, have fought the proposal. They say that any restriction would represent an attack both on business and on personal freedom for the poor. That argument is flimsy. As food prices rise, and as the federal government cuts back spending, the mayor’s attempt to safeguard the taxpayer dollar is fiscally and socially sound.

Back in October, the mayor asked the USDA to authorize a two-year experimental program for New York City. As Bloomberg envisions it, the city would work with food-stamps recipients during that time to see if food-aid beneficiaries changed their food purchases, and, if so, if foregoing soda helped families improve their health. The city noted that federal regulators have the authority to authorize such pilot initiatives, to find out what works and what doesn’t when it comes to spending taxpayer money (Congressional Republicans advocate more such experimentation, for instance, with Medicaid).

But as the USDA mulls over the idea, the pro-soda forces have pushed back. The American Beverage Association, partly funded by Coke and Pepsi, has branded the initiative as an attack on individual choice. “Once you start going into grocery carts, deciding what people can or cannot buy, where do you stop?” senior vice president Kevin W. Keane said in April, according to a New York Times story. Lobbyists say that a new restriction would put a burden on stores, whose clerks would have to separate soda from other products. Elected officials from the Congressional Black Caucus, an arm of which also receives money from soda lobbyists, say that the proposed arrangement would stigmatize poor people.

Bloomberg isn’t telling people what they can and cannot eat or drink, however. He’s simply ensuring that scarce taxpayer dollars earmarked for a program whose official name is “the Supplemental Nutrition Assistance Program” go, reasonably enough, toward assisting families for just that purpose. Taking such care with federal taxpayers’ money becomes more important as more people need government help to buy groceries. As of March, 1.8 million New Yorkers depended on food stamps, a 50 percent jump from the 1.2 million city residents who received the benefits three years ago. This demand, mirrored nationwide, strains the federal budget—and so Washington must make sure that the money is spent wisely.

The same principle holds for each individual family. In the past year, food prices have risen by 3.9 percent. Since most families’ food-stamp benefits don’t cover a family’s grocery bill, every taxpayer dollar that a parent spends on cola—that’s $100 million a year in New York—is a taxpayer dollar that he or she is not spending on milk, chicken, or lettuce. You don’t have to be an anti-soda nanny to see something wrong with that.

Sure, one can argue about the nutritional merits of lots of food-stamp eligible foods, including candy bars and the like. But soda is way over on the wrong side of the nutrition line. It shouldn’t take the place of healthy foods in the grocery carts of parents with no extra money to spare. Water, after all, is free.

In fact, the mayor’s plan would help New Yorkers exercise personal freedom in making better decisions for their families. By erroneously including soda in a nutritional program, the USDA currently gives parents and others bad information, which, as always, harms personal choice. If the government stops calling soda “nutritious” and stops subsidizing it, parents, armed with that knowledge, would be empowered to decide whether to spend their own scarce cash dollars on soda.

As for the lobbyists’ other arguments: removing sweetened sodas from the list of groceries that people can buy with food aid would neither burden supermarkets nor stigmatize poor families. Supermarkets already offer plenty of products that aren’t eligible for food stamps, from hot prepared sandwiches to diapers to cat food to cleaning fluids. Cashiers can separate “food” and “non-food” with the click of one button at the end of an order. As for the supposed scarlet letter: the government no longer dispenses “food stamps” through paper vouchers, but via a card that looks like a credit card. One has to be paying very close attention in the checkout line to see that the person ahead of him is using a combination of an electronic-benefits card and cash to buy food and non-food, including soda. New Yorkers stigmatize busy-bodies before they stigmatize poor people.

Mayor Bloomberg’s proposal, then, deserves the support of conservatives worried about the budget, liberals worried about public health, and New Yorkers trying to stretch every dollar.

Nicole Gelinas is a contributing editor for the Manhattan Institute’s City Journal.