This is the first installment in an occasional series that will examine media coverage of public initiatives aimed at ending the nation’s unhealthy-food habit.

If the way to a man’s heart is through his stomach, then New York City’s so-called Nanny Mayor, Mike Bloomberg, is shooting for center mass. He is not backing down from his attack on the social, economic, and political forces behind our national obesity scourge. With trans fats securely behind bars, two perps still at large—salt and sugar—can’t hide for long. Bloomberg’s relentless campaign transcends city boundaries, and he has recruited state governments, grassroots groups, and even corporate America as his deputies.

As the coordinator of the National Salt Reduction Initiative, New York’s Department of Health and Mental Hygiene has pressured a compelling list of food manufacturers—including notorious salt mongers like Campbell’s Soup, Goya, and Heinz—to gradually reduce the sodium levels in their products by 2014. This is arguably promising news for everyone involved. It’s even good PR for participating companies, who say consumers hardly notice the change.

But there’s another side to that coin: Many of the manufacturers are replacing the sodium chloride in their products with potassium chloride. This isn’t trivial, because there are potential health implications of this for people with kidney problems and congestive heart failure, the same people who are cautioned more than anyone to eat a low-sodium diet. Potassium chloride also has implications for people taking certain kinds of blood pressure medications and diuretics.

The salt initiative churns out press releases—and generates more than a few stories—every time a new corporate member signs on. As they cover the initiative, reporters might do well to push beyond the salt-reduction claims: What are these companies using as a substitute besides potassium? Fat? Sugar? This is an important question to ask, because these companies aren’t likely to advertise their strategies. And it’s important because consumers who may not notice the changes in their favorite products might be eating things they shouldn’t.

To mitigate that risk associated with the initiative, researchers at the city health department are painstakingly testing and documenting levels of not only sodium, but all nutrients in packaged and restaurant foods on the market, so keep an eye out for those reports.

The Salt Reduction Initiative is not just a New York thing. The city has been joined by a growing number of states, including Arizona, California, and Pennsylvania. Similar programs have been under way even longer in Australia, the UK, Finland, and other countries.

What they all have in common is the basis for their confidence that these programs will work—widely accepted research linking excessive dietary sodium to chronic diseases that take a toll on the quality and duration of life, on economic productivity, and on healthcare costs. But it’s worth noting in stories that—as with most clinical matters in general, and the potassium concern, specifically—the science is not all black-and-white. There’s always room for well-educated debate.

Genevra Pittman, in her February 14th report for Reuters Health about a study published in the journal Hypertension, included the perspective of a renowned hypertension expert, Michael Alderman, of the Albert Einstein College of Medicine in New York. A credible and well-respected critic of research that generalizes findings of the benefits of low-sodium diets to the general population, he’s been the go-to foil for the assault on salt for a long time, interviewed by the likes of Gina Kolata for The New York Times and Deborah Kotz and Kay Lazar for The Boston Globe in 2011. He told Pittman that the study doesn’t address the potential of inadequate sodium to raise heart risks.

“They begin with the hypothesis that lowering sodium intake, because it will lower blood pressure—and nobody debates that—will inevitably translate into a reduction in cardiovascular events,” he said. “But in reality, the net effect of these conflicting consequences of reducing sodium will be the health effect.”

Aside from people, according to Bloomberg, another beneficiary of his low-salt initiative is the New York City budget, which he says is burdened by an annual $4 billion healthcare bill associated with obesity.

On the federal level, economics are surely the major reason behind exhaustive research into the diets and just about every aspect of American health habits by the National Institutes of Health, the Institute of Medicine, and the Centers for Disease Control (CDC). But even these studies, which often include tens of thousands of subjects, are not always watertight in their conclusions.

This point was made during the February 21st edition of the PBS Newshour. The program included a segment in which the host, Ray Suarez, and his guests analyzed recently released CDC data about an apparent reduction in caloric intake among US children and adults.

Despite the decline in calories, obesity rates among children remain relatively unchanged. So Suarez opened the discussion with an appropriate question:

“I know there are caveats and things to be further explained, but just the gross statistics, adults consuming fewer calories from fast food, children consuming fewer calories overall, that’s good news, isn’t it?”

Michael Moss, the Pulitzer-prize winning journalist and author of a new book, Salt, Sugar, Fat: How the Food Giants Hooked Us (adapted in a fascinating February 24th New York Times Magazine cover story) wasn’t so sure. And neither was William Dietz, the former director of the CDC’s Division of Nutrition, Physical Activity, and Obesity. Deitz argued that the CDC data suggest economic factors and declining rates of physical activity as more plausible explanations for the results, and said that a much more focused effort must be made to change child obesity rates.

They all agreed that the findings should be taken with a grain of salt. (Sorry!)

Sibyl Shalo Wilmont is a healthcare journalist and emergency department nurse with insider experience in the pharmaceutical industry, academic medicine, and patient advocacy. She is a graduate student in Hunter College's dual-degree Master's in Community/Public Health Nursing/Master's in Public Health program. Follow her on Twitter @nursesibyl.