When I was a kid, there were two kinds of breakfast cereal: the kind we ate at home, and the kind we only got to eat when we went backpacking and brought along variety packs of miniature cereal boxes. The former were the basics: Kellogg’s Corn Flakes, Cheerios, Rice Krispies, Chex. The latter were the "sugar cereals": Frosted Flakes, Froot Loops, and of course the magically delicious Lucky Charms.

When I was a kid, there were two kinds of breakfast cereal: the kind we ate at home, and the kind we only got to eat when we went backpacking and brought along variety packs of miniature cereal boxes. The former were the basics: Kellogg’s Corn Flakes, Cheerios, Rice Krispies, Chex. The latter were the "sugar cereals": Frosted Flakes, Froot Loops, and of course the magically delicious Lucky Charms.


I think this was pretty common in the 1970s. My wife and her brother were allowed to go crazy on just one box of sugar cereal a year. Our son, now 16, inherited the same deal — Cheerios and Corn Flakes in regular life, then one box of Lucky Charms a year, usually around Christmas.


This kind of arrangement is what strategy professors Kathleen Eisenhardt and Don Sull call a "simple rule"— an easy, effective guide to managing breakfast nutrition that doesn’t involve reading food labels or counting calories. And if you look at the sugar content of the different old-line cereals, there really is a clear divide. Rice Krispies, Cheerios and similar cereals have far less than 15 percent of sugar as a percentage of total weight, while Frosted Flakes, Froot Loops and Lucky Charms hover around 35 percent.


By comparison, M&Ms are 63 percent sugar and Snickers bars 51 percent. Sugar cereals used to be closer to those ratios; in recent years Kellogg’s and General Mills, under pressure from child-nutrition watchdogs, have been cutting the sugar content of their sweetest products. Kellogg’s Honey Smacks still weigh in at a mouth-tingling 56 percent sugar.


Since my childhood, the cereal market has been overrun with new entrants. Some have been brand extensions of old standbys, such as Honey Nut Cheerios and Vanilla Chex. But there are also a bunch of new brands that have found their way into American kitchen cabinets, many by way of new grocery chains such as Whole Foods and Trader Joe’s.


I’m writing this from the house where I grew up in California. My father and stepmother are big Trader Joe’s shoppers, and what most of their cereals have in common are (a) claims that they are good for you and (b) lots of sugar. Not as much sugar as a sugar cereal, but much, much more than the everyday cereals of yore. Same goes for most of the oeuvre of Kashi, Cascadian Farms and Envirokidz.


Even cereal makers that started out with good intentions — such as Kashi, which still makes the zero-sugar 7 Whole Grain Puffs but was acquired by Kellogg 15 years ago and now offers a panoply of sweetened cereals — have found that the surest way to wrest market share for a new cereal is to sugar it up. These cereals generally aren’t marketed as sweet. Their makers emphasize their wholesomeness and healthiness.


The medical establishment, though, has been coming around to the idea that excess sugar consumption is a major public health problem. To be sure, breakfast cereal contributes a lot less to our national sugar overload than fruit juices and soft drinks. But a food category that once offered consumers a straightforward choice between wholesome and not now confuses them with health claims while loading them up with sugar. It’s a bad equilibrium.


It’s also no longer working for the cereal companies. Sales began dropping in the late 1990s as morning rituals changed and some people started avoiding carbohydrates. I’m not going to go so far as to claim that the cereal makers’ creeping sugar addiction is a major cause of this decline. But it clearly isn’t helping them much either.


Justin Fox is a Bloomberg View columnist writing about business.