Last week, I was invited to the penthouse suite of the Morgan, a chi-chi boutique hotel in midtown Manhattan. The place was done up with flowers and bright colors, and a gaggle of staffers from Allison Brod Public Relations and style bloggers sat on mod couches. This wasn’t a launch for Tory Burch or BMW. We had been summoned to a product reveal for...Burger King?

Eric Hirschhorn, chief marketing officer for Burger King, North America (sweater, glasses, New York digital media look), started a brief PowerPoint. A lot had changed since Burger King opened its first outlet nearly 60 years in Miami, he said, but the core business was still the same: burgers, fries, and drinks. And yet times are changing. Consumers want choices, including healthier options. They expect higher quality. The solution?

“Satisfries.”

“Satisfries?”

Yes. Burger King’s new offering, rolling out Tuesday, is crinkle-cut fries—slightly thicker than the usual fare. They’re made from the same potatoes, fried in the same oil, and processed on the same equipment as traditional Burger King fries. But get this: they’re much lighter. On a gram per gram comparison, Burger King says the “Satisfries” have 40 percent less fat and 30 percent fewer calories “than the leading French fries.” (Read: McDonald’s.) “Change in French fries over time has been about shape,” said Hirschhorn. “This is real innovation.”

Burger King has a bunch of challenges. The typical American consumer isn’t getting much of a raise, so the capacity of core consumers to eat out more isn’t rising. Competition is intense. And powerful figures in our society—from First Lady Michelle Obama to New York Mayor Michael Bloomberg—are effectively urging kids and adults to consume less fast food.

The solution Burger King has taken is not to retire existing products, or to branch out into super-healthy offering (quinoa burgers, anyone?), but to offer consumers a choice with incremental but significant improvements. Comparisons aren’t particularly easy. Burger King says that based on a 70-gram serving, the “Satisfries” would have 6.3 grams of fat and 150.5 calories. Here is the McDonald’s menu nutrition information. By my calculations, based on McDonald’s data, a 70-gram serving of McDonald’s fries would have 227 calories and 11.4 grams of fat. So the numbers do seem to add up.

How does this work? It’s a matter of engineering. You may think of French fries as a simple matter of potatoes meeting fat at high temperatures. But there’s an intervening force in many French fries, especially those that are produced on an industrial scale: a coating, a batter that can add or lock in flavor. And the innovation here, which took 10 years of research and development on two continents, is in the batter. There’s something about the makeup of the batter that ensures the potatoes absorb less oil even while producing the desired crispy/fluffy contrast between outside and inside.

Now, companies always walk a delicate tight rope when introducing healthier versions of existing popular products. Doing so implies that the product core consumers have been eating (and in very large amounts) isn’t so healthy after all. American food companies want people to be health-conscious, but not too health-conscious. Diet Coke made lots of people rethink the utility of Coke, but looking deeper into the ingredients of Diet Coke may lead some people away from sodas altogether. Any new product introduction carries the threat of cannibalization. But Burger King is hoping that the new choice will expand its universe of customers. “These are not replacing the existing French fry,” Hirschhorn said.

That’s not an unreasonable thought. It’s important for Burger King to do better in French fries. That’s partly because side dishes like fries and soda have higher margins than burgers. But it’s also because fries have not typically been BK’s strongpoint. I put it as delicately as I could to my hosts, using the “some people say” trope common on cable news. Some people say (and by some people, I meant me) that Burger King’s flame-broiled burgers are much better than McDonald’s wan offerings, but that McDonald’s wins hands down in the fries department. At the Golden Arches, the fries are thinner, tastier, crispier. Burger King executives have heard it all before, and understand that fries can be a barrier. So they are trying to change the conversation—subtly.

Burger King was sold in 2010 to a Brazil-based private-equity firm. Alex Macedo, the boyish-looking president of Burger King North America used to be an executive at Brahma beer. So I came into this event thinking there might be a Brazil theme to the new innovation: all-you-can-eat riodizio night? Caipirinha-flavored shakes? But the new management isn’t interested in radical change. “When it comes to what we eat, we know that small changes can have a big impact,” said Macedo. At the event, Keri Gans, a dietitian and author of The Small Change Diet, whose cover features a box of French fries, echoed the theme.

Fast-food places like Burger King with a global footprint and huge customer base can’t afford to do anything too radical. They don’t want customers to think in a fundamentally different way about their product. But they do need to tweak the formula so that it stays relevant. In effect, Burger King has used engineering to deliver the French fry experience without all the baggage.

But what about the taste? Readers will recall that I wasn’t really pleased with Burger King’s last potato-related innovation, which involved sticking existing French fries into burgers. But this is a much better effort. I tasted the crinkle-cut fries. And then I tasted them again. Not wanting to be rude to my hosts, I finished the small box in front of me, and then sampled a few more as I took notes. The fries taste good. They’re crispy. They taste potato-ish, like good fast food fries should. They don’t read in the mouth as “diet” or “low cal,” the way that baked potato chips or sweet potato fries do. In a blind taste test, I don’t think I—or your typical consumer—would have been able to distinguish this product from more fat-laden versions. And as I left, I had that same generalized feeling of satisfaction giving way to self-loathing you tend to get after eating junk food, only with slightly less guilt.

Which is to say I was “satisfried.”

Maybe America isn’t out of ideas just yet.