How do we provide our growing global population with healthy diets, in ways that don’t harm the planet?

The packaging was pretty—shiny purple foil wrapped around a double dark chocolate cookie. I stepped forward to reach for it.

“PROTEIN COOKIE,” the label screamed upon closer inspection. I withdrew my hand and a friend shopping alongside me reacted appropriately:

“Calm down, you’re just a cookie,” he said.

If you’re a packaged food and you want to sit at the cool kids’ table in 2019, you’d better be jam-packed with protein. And you’d better wear it like a badge of honor, too. It’s an undeniable selling point, obvious from any leisurely stroll down a grocery store aisle. There are cookies, snack bars, and smoothie mixes. It’s printed on clear plastic containers of salad. Buy “protein greens” or “textured vegetable protein” (sold as TVP® by Bob’s Red Mill). You want clean protein? Builder’s protein? Cinnamon horchata protein? Cold brew coffee with collagen protein? Cheerios with protein?

Check, check, check, check, and check!

It’s dizzying. You’d think the protein craze is a concerted push to solve a culture-wide protein deficiency problem—only there isn’t one. Most Americans eat double what the average person needs (the recommended amount is 0.36 grams per pound of body weight). Since at least the 1980s, Americans have gotten more than 15% of their daily calories (pdf) from protein, according to the US Centers for Disease Control and Prevention (CDC). Health experts have suggested that, for the average person, that proportion should be closer to 10%.

This obsession with protein is not only unnecessary. It’s unhealthy, because it sets consumers and citizens up for confusion. Instead of focusing on what’s actually important—portion control and total calorie intake—people are led to believe they need to understand how to balance complex nutritional compounds.

There are three macronutrients in our diet—fat, carbohydrates, and protein—and in the last several decades, each one has experienced fad-like status and a fall from grace in the face of evolving nutrition science. Behind each downfall is the same knowledge gap: Humans don’t really understand macronutrients all that well, not when they are isolated from real food and studied on their own.

Nutrition science is a notoriously difficult field. As one health professor at Stanford University put in in a 2005 paper that appeared in the journal PLOS Medicine, “Almost every single nutrient imaginable has peer reviewed publications associating it with almost any outcome.”

In the 1970s, scientific evidence led some nutrition experts to encourage people to move away from fat-laden foods and shift more caloric intake to carbohydrates such as bread and potatoes. As we know now, that didn’t stop Americans from getting bigger. Three-quarters of the American population is overweight or obese, according to the United States Centers for Disease Control and Prevention.

In the early 2000s, some leading health experts reversed course.

“Fat is not the problem,” Harvard University nutrition professor Walter Willett told the Los Angeles Times in 2010. “If Americans could eliminate sugary beverages, potatoes, white bread, pasta, white rice and sugary snacks, we would wipe out almost all the problems we have with weight and diabetes and other metabolic diseases.”

So people recoiled from carbs.

And the cycle continues. We collectively watch as macronutrients climb aboard the merry-go-round of popularity, only to tumble off as new nutrition science—a lot of it inconclusive and difficult to decipher—becomes public and people clumsily work to incorporate that new knowledge into their diets. The disorienting messaging has led to poor nutritional choices (consider how we doubled down on carbohydrates when fat lost its luster). Meanwhile, food marketers have consistently taken full advantage of the cycle.

We work ourselves into a rhythm of confusion. Right now fats and carbs are out, and protein is in. But for how long?

The science around protein hasn’t always been so sunny. In the 1980s, ingesting large amounts of the macronutrient was connected to kidney problems, according to several studies. Over time, though, other researchers came up with conflicting results, quelling a backlash against protein.

“I’m not aware of any convincing evidence that eating too much protein is a problem except that it turns into fat,” says Marion Nestle, a New York University food studies professor and previous member of the US government’s Dietary Guidelines committee. Still, nutrition science is ever-evolving, and it isn’t beyond the realm of possibility that science may one day kick up new reasons to be skeptical of prolific protein intake.

The World Health Organization has determined, after reviewing a vast body of nutrition research, that heavy red meat consumption is linked to colorectal cancer. I wonder if it’s possible that some future piece of research will specifically link excess protein consumption to a malady as recognizable and feared as cancer.

For that reason, all of us—scientists, journalists, food companies, and consumers—need to revamp the way we talk about food. Nobody understands fully how macronutrients, when isolated, impact our diverse bodies. Researchers want to get their work published; journalists want to translate that complex science into meaningful messages for everyday people; food marketers want to make money selling food; and consumers simply want to feed themselves and their families foods that won’t harm them.

“We shouldn’t be talking about nutrients at all, we should be talking about foods,” Nestle says. “Because people aren’t eating nutrients, they’re eating foods.”

But focusing on foods, portion sizes, and calorie intake isn’t en vogue. And the internecine battle among macronutrients is only heating up. With a backdrop of loud food marketing and people pushing fads such as the Atkins, keto, and paleo diets, the fight over what people should be eating is being waged in government halls, too.

As reported by Politico, proponents of high-fat, low-carb dieting are duking it out with plant-based diet proponents in an effort to shape the government’s forthcoming recommendations on how people should be eating. The resulting policy document, called the Dietary Guidelines, might not be breezy reading for everyday people, but it does inform how the military and public school system will spend many billions of dollars on food.

And that’s enough reason to be alarmed by a culture in which we champion hard-to-understand macronutrients. While health across the US and a handful of other western nations continues to deteriorate, there are clear beneficiaries in this system built on confusion and hype. So the next time you see a cookie touting its protein content, consider who actually needs you to eat it: your body, or an amorphous industry that profits off a science that’s tough to talk about in the first place.