Our fast-food empire: "You deserve a break today" can be a pretty appealing proposition.

In his landmark book Fast Food Nation, Eric Schlosser reported that, in a global marketing survey, McDonald's Golden Arches proved to be a more widely recognized symbol than the Christian cross. The arches are second worldwide, after the Olympic rings. The cross comes in third.

Of all the changes that struck American culture in the last quarter of the 20th century, the explosive growth of the fast-food industry would have to count as one of the most destructive. That's a big claim. We're talking about a period of history that saw the advent of music videos, infomercials, and call-waiting. But I'll stand by it.

Foodways are among the most essential defining elements of any culture; in the past few decades, ours have changed almost beyond recognition. Twenty-first century America has, in large part, left behind regionally grown, home-prepared food for globalized, pre-packaged, sweetened, and fatty convenience stuff. Just as we've surrendered control of our free time, and even our inner consciousness, to the TV and advertising industry, we've turned over responsibility for much of our daily sustenance to a few transnational marketing corporations.

We are what they sell us. And, in exchange, the lords of the fast-food empire have promised to free us from cooking, dishwashing, and (at least briefly) from complaining children. The consequences of this bargain are written across our strip-mailed landscape, our low-wage economy, and our increasingly bloated bodies.

Researchers have pretty much decided that this cultural shift to prepackaged, high-fat convenience food (washed down with torrents of soda pop) is the main factor behind America's obesity epidemic, and especially our startling pandemic of childhood obesity. According to the Centers for Disease Control and Prevention (CDC), 16 percent of American children are now overweight. That represents a 300 percent increase since the early 1970s. During that same time period, the percentage of meals American families eat at fast-food restaurants more than doubled.

And the American obesity epidemic is spreading globally. Wherever our fast-food chains establish a presence, increases in the percentage of people who are overweight follow. Similarly, immigrants to the U.S. from countries where obesity is rare see their children becoming overweight in the new land.

These trends can only be expected to get worse in the years ahead, because the genius of fast-food marketers has been to focus their efforts on children--even, for the first time, preschool-age children. The fast-food marketers have managed to colonize the commercial-free zone of PBS children's programming. Our kids first saw Ronald McDonald in those "underwriter messages" that run before and after PBS programs. Then, in 1999, PBS surrendered utterly and licensed Teletubbies merchandise for fast-food giveaways.

The whole promo package--the "kid's meals" with the collectible lines of toys, the tie-ins with the latest hot kid movie (sometimes even if it's rated PG-13), the clown and cartoon character mascots, the in-store playgrounds--it's all designed to make children nag their parents to go to McDonald's (or Burger King, etc.).

The strategy behind the marketing effort is to get children into the fast-food habit before they're able to understand that actions have con sequences. The industry's partners in this enterprise (witting or not) are the harried and overscheduled parents whose two-job lives leave them too exhausted to fight the excruciating battle of teaching children to defer instant gratification (french fries and chicken nuggets) for the long-term goal of a healthy body (which requires a lot of broccoli). And the marketing strategy works. If you give in and go fast food, the kids don't complain about eating the stuff. The playground keeps them out of your hair. And you don't have to make them clean up. Around 6 p.m., "you deserve a break today" can be a pretty appealing proposition.

We're so saturated with the stuff now that even those of us who grew up in a different world have difficulty remembering a time when childhood was not an advertising gimmick. But, every once in a while, we're reminded. One shudders to think, for instance, of C.S. Lewis living until 2006 and seeing the Narnia characters as action figures given away with a McDonald's Happy Meal.

Danny Duncan Collum, a Sojourners contributing editor, teaches writing at Kentucky State University in Frankfort, Kentucky. His book, Black and Catholic in the Jim Crow South, has just been published by Paulist Press.