If Wal-Mart, the Lucifer of multinational corporations in many liberal eyes, sees the fiscal sense in stocking an increasingly wide array of organic foodstuffs, consumer habits truly are changing.

Not fast enough, though, for documentary filmmaker Robert Kenner, whose eye-opening "Food, Inc." should win a few hearts and minds regarding what we put in our stomachs.

Several things -- too many, probably -- are going on in "Food, Inc.," all connected.

Kenner begins by tracing the impact of 20th century American fast food on industrialized food production, and notes that when McDonald's brought factory assembly-line strategies into practice, everything changed. McDonald's became a universe of beef-purchasing power unto itself.

Its cows, like so many millions of other feedlot residents, consume corn instead of grass; the humans in our increasingly obese nation eat a ton of corn as well, courtesy of high-fructose, heavily subsidized corn syrup found in everything from ketchup to Twinkies to Coke. As a Brooklyn, N.Y., doctor in another food doc, "King Corn," put it: American food policy ensures that "we subsidize the Happy Meals -- but we don't subsidize the healthy ones."

Are the federal regulatory and protection agencies doing enough to keep us safe from E. coli outbreaks and the like? The film answers that one with a firm "no."

Does eating organic food lead to a healthier diet and a healthier environment? What do you think?

The film got virtually no cooperation from representatives of the dominant players in industrial food production, including Tyson (we see a chicken processing factory in full swing), Monsanto (whose strong-arm business practices come off very, very badly) and others.

As a result, "Food, Inc." is a rangy, well-articulated essay rather than a compelling point-counterpoint.

Kenner can be accused of substituting surface tension, with threatening music cues riding in on almost every sequence, for a higher brand of dialectical tension -- the accused getting time, and room, to debate their accusers.

Personally, I don't need much convincing. I believe organic's worth the money.

The most eloquent arguments in "Food, Inc." belong to Michael Pollan, who wrote "The Omnivore's Dilemma" and who served as project consultant.

"Fast Food Nation" author Eric Schlosser is onscreen a lot as well. The tobacco industry offers a guide, Schlosser says, on how "irresponsible behavior can be changed" by consumers and their government.

Pollan puts it this way: "We've skewed our food system toward the 'bad' calories." And, he says, we must try to arrive at the day when, on a trip to the supermarket, "the carrots are a better deal than the chips."

Food Inc. MPAA rating: PG (for some thematic material and disturbing images).

Running time: 1:33.

Featuring: Eric Schlosser ("Fast Food Nation"); Michael Pollan ("The Omnivore's Dilemma"); Gary Hirschberg (Stonyfield Farms); Joe Salatin (Polyface Farms).

Directed by Robert Kenner; produced by Kenner and Elise Pearlstein.

A Magnolia Pictures release.