When it comes to food writing, there may be no rhetoric more illuminating, and more depressing, than the text on instant oatmeal boxes. Within that sorry subgenre, there may be no better specimen than the writing on the back of each box of Better Oats Oat Revolution® Strawberries and Cream instant oatmeal—with flax.

“Is this breakfast or dessert?” ask the marketers of Better Oats, a subsidiary of MOM Brands. “It’s actually a healthy, hearty breakfast that tastes like dessert,” they conclude.

What makes this breakfast so healthy and hearty? Better Oats has answers: “This healthy whole grain oatmeal contains flax for added ALA Omega-3, and is enriched with antioxidant vitamins A and E.”

And what makes this breakfast taste like dessert? Here, Better Oats is more circumspect, but the full tablespoon of sugar in each small packet of oatmeal probably doesn’t hurt. The stuff is, by weight, more than 40 percent sugar. In other words, it is candy, or the meal formerly known as dessert.

Why is it that otherwise health-conscious consumers—people who worry about omega-3 fatty acids and monitor their dietary fiber intake—don’t worry about eating a breakfast that contains enough sugar to send a beehive into retirement? Why is it that vegetable oil-soaked, sugar-packed granolas seem so much heartier than Cap’n Crunch? Why is it that Greek Gods honey-flavored Greek yogurt seems wholesome, even though each 24-ounce container has 99 grams of sugar? Why is it that every time I eat a Baby Ruth bar I feel a little better because at least it contains real peanuts?

The answer, I think, is partly a function of how we tend to think about nutrition, and partly because we have a set of basic human blind spots that are best illuminated not by any FDA manual, but by Greco-Roman literature—specifically, the story of the Trojan horse.

You know the tale. The Greeks and Trojans fight for a decade. Finally, tired of laying siege to Troy, the Greeks build a large wooden horse, leave it outside the city gates, and go away. “I fear the Greeks, even bearing gifts,” one Trojan frets. His fellow citizens, ignoring him, bring it into their city. They lose the war that night, when a passel of Greek soldiers emerges from the horse’s belly, opens the city gates, and lets in a horde of their compatriots.

Why did the Trojans act so stupidly? The horse looked to them like a ritual object, and maybe they couldn’t see past the sacred symbolism to the possibility of a strategic ploy. Or maybe—and this possibility, I find more likely—they simply saw what they wanted to see, after 10 long years of war. Overcome by their desire for a truce, accepted a tool of war as a symbol of peace.

I tell this little tale not because I'm a pedantic classicist schmuck (although I probably am), but because those two explanations for the Trojan mistake—a faith in what’s pure; the blindness induced by desire—seem to me not just classical inventions, but rather elegant ways to explain certain aisles of the American supermarket.

Call them Trojan horse foods: nutritiously pleasing ingredients (oats, yogurts) that conceal a whole host of junk. We struggle to think of them as unhealthy, because they seem so pure, so wholesome, so stocked with goodness. We want them to be healthy because we have certain dietary cravings, and these foods taste so, so good. And they taste so, so good, of course, because they’re filled with the dietary equivalents of marauding Greeks. Namely, sugar, sugar, and more sugar.

The classic example of a Trojan horse food is the oat, and, with an honorary nod to MOM Brands and the copywriters of Better Oats, the most skilled purveyors of this particular Trojan food would have to be Quaker, whose long roster of granola bars, cereals, muffins, and instant oatmeals eclipses its handful of plain, rolled oat products.

Oats really are packed with the kind of nutrients and complex carbohydrates that can power the smooth running of your metabolic engines. The issue, of course, is that Quaker—which was purchased by PepsiCo in 2000—uses its good nutritional reputation to sell an ungodly amount of sugar. And, as a growing body of evidence shows, processed sugars really can be toxic for you, in ways that researchers are only beginning to understand.

In their unadulterated form, oats are pretty much free of simple sugars. A single packet of Quaker Maple and Brown Sugar instant oatmeal, though, contains a full tablespoon of sugar. The Quaker Chewy Dipps Chocolate Chip granola bar is more than 40 percent sugar by weight. Just for reference, draft guidelines from the World Health Organization suggest that adults eat no more than 20-25 grams of sugar per day. A couple Maple and Brown Sugar packets will get you there before you’ve finished your first cup of coffee.

Those same Maple and Brown Sugar packets bear an FDA-approved seal proclaiming them heart healthy. This may seem odd, once you dig into the literature a bit and realize that there’s a link between sugar consumption and heart disease. It may also seem odd, as you troll the Quaker website’s extensive healthy eating section and dig into their guide on how to read a nutritional label, that the company’s health gurus never once mention the need to check how much sugar a food contains.

It’s not just Quaker, of course, that plays these Trojan horse games. Organicness, too, can offer a patina of healthfulness to unsavory substances. That organic, gluten-free, macrobiotic, non-GMO, vegan GoMacro bar, with “time-released energy,” that costs $3.39 in the aisles of Whole Foods? Yep, organic rice syrup—i.e., sugar—is still its main ingredient, no matter how macro its biotics may be. That nice box of Kashi Organic Promise Cinnamon Harvest cereal? It has nearly as much sugar as two cans of Coca-Cola.

Sure, it’s probably better to eat a Quaker Chewy granola bar than a Snickers. But marketing your oatmeal-based-dessert food as a healthy, kid-friendly breakfast-and-snack option really is deceptive, no matter how much dietary fiber it may contain (and no matter how many FDA-approved health claims the box may bear). The Trojans did much better against the Greeks they could see than they did against the Greeks they could not. Better, perhaps, to eat the junk we know to be junk, rather than the stuff that pretends to be something else.

The problem, really, as the food writer Michael Pollan has pointed out with particular clarity, is that we’ve become so accustomed to thinking about healthfulness in isolated terms—as a function of dietary fiber, or omega acids, or antioxidants—that take as healthy anything that contains those miracle molecules, even if they’re encased in junk.

A partial solution, perhaps, would be to adopt the kind of traffic light food labeling required in Britain. There, a simple, color-coded system shows whether foods have low (green), moderate (yellow), or high (red) levels of certain substances. In Britain, the sugar levels in most of Quaker’s flavored instant oat products would earn the packaging a big red mark, right on front of the box.

Alternately, we could just paraphrase a little Virgil and put it on the sides of our food packaging: Fear PepsiCo, even bearing dietary fiber.

Quaker did not return a request for comment at the time of publishing.