Earlier this year, the FDA sent the maker of Kind Bars a stern message. The company, which sells granola bars, among other things, was using the the word "healthy" on its packaging. And that wasn't going to fly.

"The labels of the aforementioned products bear the claim 'Healthy and tasty, convenient and wholesome,'" the warning, which is available online, said. "However, none of your products listed above meet the requirements for use of the nutrient content claim 'healthy.'"

Specifically, the government was talking about the company's Fruit & Nut Almond & Apricot, Fruit & Nut Almond & Coconut, Plus Peanut Butter Dark Chocolate + Protein, and Fruit & Nut Dark Chocolate Cherry Cashew bars, which, it said, would be removed from stores if the packaging wasn't changed. The bars, which are essentially just nuts and fruit and little sugar, had too much fat for the FDA's liking, and Kind acquiesced, because what choice did it have?

But the battle is hardly over. By engaging the company publicly, the government opened the doors for a broader and thornier discussion, which revolves around what has become an increasingly provocative point of contention: What exactly does "healthy" even mean? And Kind gladly stepped through.

Last week, the company announced that it was launching a citizen petition, protesting what it argues is an outdated and misleading official policy regarding the use of the word "healthy." While Kind's protest comes with a tinge of self-interest—after all, the company would like nothing more than to return to its old labels—it raises an interesting question about what can and can't be called healthy under current regulations.

Per FDA guidelines, the moniker is only allowed to be used when foods contain 3 grams or less of fat and 1 gram or less of saturated fat (for seafood and meat it's 5 grams of fat and 2 grams of saturated fat). That, Kind points out, precludes several foods widely considered healthy by doctors and nutritionists—nuts, avocados, olives, and salmon, most notably.

"The current regulatory approach for food labeling claims limits the ability of food producers to tell consumers that products containing certain ingredients – such as nuts, whole grains, seafood, fruits, and vegetables – are healthy and are recommended as part of a beneficial diet," David Katz, who is the director of the Prevention Research Center at Yale University and a senior nutrition advisor to KIND, said in a statement.

The government is also reportedly reconsidering its long-held villainization of fats, which, Kind says, could soon put the regulations at odds with the new Dietary Guidelines, which are expected to be released any day now.

But that argument doesn't hold up, according to Marion Nestle, who is the Paulette Goddard Professor of Nutrition & Food Studies at New York University. While she concedes that Kind's product is admirable, she says that the company's campaign is misleading.

"Health claims are about marketing; they are not about health," she said.

The FDA's regulations were put in place as a concession of sorts. The government didn't encourage companies to tell customers that their products were not only good, but good for them—companies clamored for the right. Health claims used to be disallowed, but the food industry pressured the government enough that it allowed them, given certain restrictions, in exchange for the Nutrition Facts label that is now required on all packaged and processed food.

The clearest sign of this—that health claims might not be as altruistic as they seem—is that the regulations only apply to processed foods. Whole foods, like fruits, vegetables, and nuts—which are arguably the healthiest of all—can't carry any health claims. In that light, Kind's assertion that the current regulations stipulate that foods like nuts and avocados aren't healthy looks a little more suspect.

The truth is that unprocessed nuts can't be called healthy because there is no such thing as a label for any unprocessed food. Why should cleaning them, roasting them, and packaging them—which is perhaps the most benign form of food processing that exists—change that? The same can be said for any fruit or vegetable, sliced and then put inside plastic. Or of Kind's bars, which are mostly made from whole foods.

The problem, Nestle says, isn't the way in which the government regulates the use of health claims—it's the fact that it has to deal with them at all. "Foods are foods, not drugs," she said. "I don't see why companies should be allowed to carry any health claims."

"The kind thing for Kind to do would be to stop angling for health claims to promote its products," she added. "I like Kind, I think the product is really pretty good—real foods stuck together with a little sugar—but leaning on health claims diminishes the image the company is trying to project with its product."

Making such a fuss about it might not help much either. The more Kind, which isn't associated with junk food or unhealthfulness, doubles down on the ability to call its products healthy, the more people might begin to question why it matters, and whether, as Nestle believes, it's merely a matter of marketing.