For years we've exported dark chicken meat to Russia—but that market is drying up.

There's no question that Americans overwhelmingly prefer white chicken meat to dark. We eat chicken almost 10 times a month on average—according to data from 2007— but on less than two of those occasions do we choose chicken legs, thighs, or drumsticks. At the household level, this isn't problematic; families can buy prepackaged white meat instead of whole birds. But magnify this preference millions of times over on a national scale, and the imbalance could, theoretically, lead to canyons of perfectly edible chicken going to waste.

Historically, Russia has helped keep this hypothetical from becoming a reality. Through a miracle of yin-and-yang cultural predilections, Russians actually like gamier dark meat. And since the collapse of the former Soviet Union, they have imported it in stunningly large quantities. In 2009 alone Russia doled out $800 million for 1.6 billion pounds of U.S. leg quarters.

Recently, however, the Russian appetite for our chicken legs has waned. Last January, Prime Minister Vladimir Putin barred U.S. chicken from Russian shores, supposedly because it's treated with "unsafe" antimicrobial chlorine. Although Russia subsequently lifted that ban, in November it prohibited the use of frozen poultry in processed products (again citing safety concerns), effectively preventing the use of American chicken in Russian nuggets—since it's shipped frozen. There's no scientific evidence that chlorination, much less freezing, poses any danger to health, so it's doubtful that safety is the real impetus for the bans. It's far more likely that Putin simply wants Russia to become less reliant on imports. (In fact, he's said publicly that he intends for Russia to be fully self-sufficient in chicken production by 2012.) Assuming Putin gets his way, American poultry companies will have to rely on alternative outlets for its dark meat.

This raises the question of why Americans are so enamored of white meat to begin with. Why do we treat dark meat—perfectly edible dark meat, savored abroad—as a waste product?

Up until 50 years ago, retailers sold chicken almost exclusively in the form of whole birds. This practice began to change in the 1960s, when federal inspection of poultry slaughterhouses became mandatory and chicken producers realized they could save money by recycling substandard carcasses into bits and pieces rather than simply discarding them.

The most popular cut—then as now—was the breast. According to several food scientists I interviewed for this article, this preference developed in part because of the perception that chicken legs are tough. This may have been the case in our great-great-grandparents' day, when chickens were almost exclusively free-range and regular exercise resulted in muscular legs. With factory farming, these muscles atrophy, and the legs become quite tender. Nevertheless, the habit of rejecting legs in favor of breasts seems to have been passed down from one generation to the next.

Tenderness isn't the only reason Americans reach for breasts above all other parts; color also shapes this choice. According to Dr. Marcia Pelchat of the Monell Chemical Senses Center, consumers unconsciously perceive dark meat as dirty when compared to the breast, perhaps because it's situated at the back and bottom of the animal. There's nothing actually harmful about dark meat: The brown hue comes from a compound called myoglobin, which helps transport oxygen to the muscles so that they function efficiently. As chickens spend most of their lives standing, their legs are full of it. Inversely, since chickens don't fly, as ducks or geese do, their breast muscles contain only a negligible reserve of myoglobin resulting in significantly lighter meat in their upper bodies. Of course few people care to study up on chicken biochemistry before dinner—which brings us squarely to another reason why chicken legs rarely make it into our shopping carts: We're squeamish. "When you're faced with a chicken leg, there's no hiding the fact that it's the leg of an animal," says Pelchat. The modern consumer is nearly as averse to seeing a leg on their plate as they are to seeing a fish head. We have grown accustomed to buying boneless, bloodless slabs of meat in cellophane-wrapped trays and don't want to be reminded of the provenance of our meal, that it came from an animal that was once living, breathing, and moving. A nondescript breast fillet appeals since it bears little resemblance to an actual chicken.

Ask people why they don't like dark chicken meat, though, and they're unlikely to cite an indisposition to digging into unvarnished animal parts. According to William Roenigk, senior vice president of the National Chicken Council, Americans say they choose white chicken meat by a 2-to-1 margin mainly for health reasons. A quick Google search or a flip through a fitness magazine yields advice condemning fatty legs in favor of the lean breast. And the poultry industry hasn't been shy about jumping on this bandwagon, either. Take the 2007 Perdue commercial featuring a lithe Jim Perdue bounding through his offices in a fit of acrobatics while promoting his 99 percent fat-free, high-protein, carb-free, hand-trimmed "guaranteed healthy" breasts. Or the Perdue Chicken Cookbook from 2000, in which Frank Perdue's wife Mitzi advises readers to "choose breast meat" so as to avoid fat and calories. She even writes that "Frank watches his cholesterol and I've never seen him go for anything but breast meat."

Even the U.S. fast-food industry uses breast meat in its chicken products to profit from rising consumer beliefs that white meat is nutritionally superior. In October 2003, McDonald's reformulated its 30-percent dark-meat recipe for Chicken McNuggets to create a reduced-calorie, all-white offering. The new six-piece pack shed 60 calories and 5 grams of fat. Though costs were higher, McDonalds did not increase the price of the nuggets; the well-publicized gamble paid off and sales increased by 35 percent.

The catch is that when it comes to fat and calories, there is very little to distinguish between boneless, skinless chicken breast and boneless, skinless thighs. According to the Department of Agriculture, 100 grams of the former contains 0.56 grams of saturated fat and 114 calories, and the latter 1 gram of saturated fat and 119 calories. Dark chicken meat is also nutrient rich, containing higher levels of iron, zinc, riboflavin, thiamine, and vitamins B6 and B12 than white meat.

The myth that white meat is significantly more healthful than dark chicken meat is nearly as old as the retailer practice of selling chicken in parts. In the 1960s and '70s, medical studies revealed links first between cholesterol and heart attacks, then between cholesterol and high-fat foods, like red meat. The medical community advocated that Americans should consume less beef and opt instead for lower-fat options such as chicken. With the fervent encouragement of the chicken industry, the newly health-conscious nation heartily embraced this advice and chicken consumption began to rise steeply. The average American was eating 36 pounds of chicken a year in 1970; by 1985 this had risen to 51 pounds, at the expense of beef. * Poultry producers also realized that they could market and advertise the slight disparity in calories and fat content between dark and white chicken meat to their further advantage—not only to perpetuate the chicken craze, but also to retail a "premium" poultry product that could be sold at a higher price. They didn't deliberately malign chicken legs; they simply wholeheartedly extolled the salubrious qualities of breast meat. Chicken was a healthy option, but chicken breast was the healthiest, and it turned out that consumers were willing to shell out for the well-being of their families.