As you may have heard, McDonald’s announced Tuesday that it’s revamping its Happy Meals to include apples or other fruit as standard instead of an option, make milk the beverage unless a customer asks for soda and reduce the size of the fries portion from 2.4 ounces to 1.1 ounces. All told, the changes are expected to cut the calorie count of a Happy Meal by about 20%. Moreover, the fast-food giant will tinker with its grown-up menu as well, with the aim of cutting (for example) salt content by more than 15% by 2015.

The company denied that political pressure, such as San Francisco’s ban on existing Happy Meals, was a major factor. But a lot of for-your-own-good “food policy” types are keen to take credit.

They aren’t so keen to associate themselves with the week’s other big food announcement: Faced with a consumer revolt, Campbell’s is putting salt back in its 31 Select Harvest soups “in an effort to improve the way they taste,” as the L.A. Times reported. Investors applauded, with the company’s stock price ticking up 1.3%.

Now in a sense, both these stories illustrate a basic process of capitalism at work: Businesses are always experimenting with their offerings in hopes of staying current with consumer trends. And interest in healthier and lower-calorie food options, especially for kids, is definitely one of those trends.

At the same time, successful companies tend to give customers what they actually do like rather than what they know they’re supposed to like — a lesson Campbell’s learned the hard way.

If anyone’s feeling an uneasy soup-stain-on-shirt-front sense of embarrassment, it should be Mayor Bloomberg’s Health Department. That department has gone on a huge public campaign to encourage odium for sodium, with processed soup a designated villain, as with a notorious public-service ad showing salt crystals spraying out of a can of the product. Doesn’t seem to be working, now, does it?

In fact, the science on salt and health has long been more complicated than you might think. Per Scientific American, “In just the past few months researchers have published seemingly contradictory studies showing that excess sodium in the diet leads to heart attacks, reduces your blood pressure or has no effect at all.” This month, the venerable science monthly ran an article by Melinda Wenner Moyer under the startling headline, “It’s Time to End the War on Salt.” City health commissioner Thomas Farley must have needed reviving with smelling salts, assuming his office hasn’t tried to ban those yet.

The political campaigns again and again seem oddly unrelated to the science. The Obama administration’s proposed guidelines on marketing purportedly unhealthy foods to kids, for example, are so restrictive that according to a Kraft foods official, “foods like reduced fat peanut butter or 2% milk string cheese could not be advertised to children.” Meanwhile, restrictions on “word of mouth” marketing could bring down federal wrath on promoters of Girl Scout cookies. Chocolate milk bans are moving forward in various states and cities despite pleas from school food managers who say it’s the only way they can get some kids to drink milk.

As for McDonald’s, the company would seem — on the surface, at least — to be taking some fairly daring risks. For example, it’s doing away with the gooey caramel dip that is many kids’ reason to go with the current apple option.

But most press accounts missed this significant bit of wiggle room the company is giving itself: As USA Today reported, “Customers can get all fries or all apples if they ask,” rather than the standard half-portion of both. The company says, by the way, that it doesn’t intend to change the price of the meals.

It might also be worth noting that the portion of fries in the current Happy Meal is so big that many kids (especially the littlest) currently wind up sharing it with their parents. Cut off from that covert snack source, some of those parents might well start ordering a bigger portion of fries on their own behalf. I wonder whether anyone at McDonald’s headquarters has thought of that.