Joining "Super Size Me" and "The Future of Food" in the fast-sprouting subgenre of we-are-what-we-eat documentaries, "King Corn" follows two young Yale grads, Curt Ellis and Ian Cheney, on a journey to discover "how an acre of corn could get from a field in Iowa into our hair."

Did you know that human hair acts as a kind of tape recorder of one's diet? That the jumbo bag of Doritos you thought you scarfed down in secret last spring is now literally hanging over your head?

"I was 50 percent corn," says Ellis, the "King Corn" co-star who will be in Minneapolis on Friday night to introduce screenings of the film at Oak Street Cinema and answer questions afterward. (He'll also lead a discussion at the Wedge co-op on Friday afternoon.) "The University of Virginia scientist who did our isotope analysis really shocked us," Ellis says during a phone interview Tuesday from his office in Portland, Ore. "Ian was told he was 58 percent corn. We were eating an unbelievable amount of corn. What we found is that high-fructose corn syrup is in almost everything these days — even toothpaste."

Despite stop-motion animation of corn seeds bouncing around a U.S. map, "King Corn" runs a little low on the fun quotient. Ellis and Cheney acted up audaciously at Yale, releasing sheep on campus and covering a Frisbee field with manure to make political points, but onscreen, alas, they make Morgan Spurlock look like Chris Rock. (The film was directed by Ellis's cousin, Aaron Woolf.)

Plenty of nutritional value
What makes "King Corn" worthy, appropriately enough, is its nutritional value. As Ellis and Cheney grow corn with the help of an Iowa State University agronomist, then trace its geographic progress to a Brooklyn bodega's soda cooler and beyond, the film reveals not only that corn is widely used in the United States as a cheap substitute for sugar, but also that the current system of government subsidies — revamped in 1973 to favor big business — rewards the mass production of cheap corn at the expense of family farms and the health of animals and people.

Corn-fed beef is "fat disguised as meat," says one expert interviewed in the film, which works most effectively as an endorsement of grass-fed beef and a stern warning against the "liquid candy" commonly known as soda pop.

Diabetes and obesity are just two of the negative health effects that stem from a national fast-food diet based on high-fructose corn syrup. But Ellis, who blogs about dietary issues for Culinate.com, doesn't try to disguise the appeal of cheap food either in the film or in conversation. "It's a blessing that we can't ignore," he says of cheap food. "In fact, it's the kind of thing that made it possible for my college friend and me to go horse around in Iowa with a movie camera. But we in the United States have taken a reasonable idea so far that we've made our children sick and wiped out the family farm."

What can we do?

"I think there is a growing interest in this country — particularly among young people — in reconnecting to where food comes from," says Ellis. "Among political causes, I feel like the most important things are the still the most fundamental ones — the food we eat, the buildings we live in, the clothes we wear."

In fact, he says, the issues of corn are "pretty darned important right now."

Growing attention 

"You notice the presidential candidates doing everything they can to please Iowa farmers — largely by talking out of both sides of their mouths. They're saying they support the farm subsidies (by sending) taxpayer money to promote all-out production of commodity crops like corn and soybeans, but at the same time they're saying we have a public health care crisis in this country. Things are changing, though. There was an article about us in Congressional Quarterly ... that suggested there's a real momentum building in terms of the question of the role that food and agriculture should play in the presidential election."

Ellis is a self-described "burger lover" who makes a dietary exception for corn-filled ketchup. What's he hoping to eat when he's in Minneapolis? "That's the most important question!" he says with a laugh. "I had some really good Vietnamese food in Minneapolis when I was there last time, but I don't know where it was grown or how it was raised. I imagine I'll have a snack at the Wedge on Friday. But I haven't even gotten to thinking about dinner yet."

Might he consider a grass-fed beef burger at the Bryant-Lake Bowl?