“We have done the right thing. We have done the moral thing,” Greg Creed told the newspaper. “What we haven’t done is toot our horn. No one out there suspects we have done it because we haven’t changed the taste.”

The hesitancy to horn-toot — or at least to toot toward the wrong people — isn’t corporate modesty. “People don’t want the taste to change,” Creed explained later in the interview. “If I came out and said ‘new low sodium Taco Bell,’ some people will think it will taste like you-know-what, and they are not going to come.”

And therein lies the central conundrum of marketing fast food in an age when health concerns are rising among consumers, and public-image concerns are rising among fast-food companies. Taco Bell obviously can’t switch over to salt-free, soy-and-kale burritos. But Yum also feels, with some justification, that it must at least provide a sop to critics of its unhealthy fare. The downside it that it makes it seem that Yum is trying to have it both ways.

And when it comes to salt, the conundrum is even more vexing. Recent studies have indicated that salt might not be as bad for us as previously thought. One published just last week by JAMA Internal Medicine indicates that salt may have no effect at all on the risk of heart disease among older people. The study is full of caveats — for instance, salt intake was self-reported among the subjects, whose average age was 74. But it comes on top of other recent studies that have clouded the salt picture and called into question whether dietary guidelines on salt consumption by the likes of the American Heart Association really make any sense.

That might make it sound like it should be easy for Yum and other companies to just keep selling salt-filled meals. Unfortunately, it’s not that simple. For one thing, the recent studies notwithstanding, the consensus on salt for now is still that too much is bad for you — in particular, that it causes or worsens hypertension. For another, because of salt’s reputation, the food industry has invested big in new salt alternatives, and often markets foods based on their reduced salt content. That’s how Yum is able to reduce salt a bit without customers noticing. There are a lot of sunk costs there. The recent studies indicated that salt might not be so bad are likely more a source of frustration for peddlers of salty eats than anything else. Why didn’t these studies come out 20 years ago, before companies invested in “low sodium” marketing?

But make no mistake: the fast-food industry is still heavily reliant on salt, just as it is on fat and sugar — Yum definitely included. The company’s goal is for 15% of its menu items at Taco Bell, Pizza Hut, and KFC to conform to recommended per-meal limits by the end of this year — rising to 20% by 2020. That’s well short of a major about-face. Even among the large fast-food chains, Yum’s fare is particularly salty in general. Taco Bell’s Beefy Five-Layer Burrito contains 1,290 milligrams of salt. That’s more than half of the USDA’s total recommended intake for a single day.

But the same things that make Yum’s food unhealthful also make it a draw, particularly among young men, a core Yum constituency for whom reduced salt is generally very low on the priority list. Pleasing both them and critics like the Center for Science in the Public Interest is a tricky proposition.