Almost all of us will speak out against animal cruelty and manmade environmental calamities. We generally support healthful lifestyles and the survival of independent small businesses. Still, day to day, very few of us embrace or advocate our principles at the table.

Which is why Christopher Quinn’s somber documentary about the meat industry may leave many viewers with a queasy feeling, especially after mealtime. It finds interlinked crises in the exploitation of animals; the hazardous use of antibiotics and hormones; the pollution of air, soil and water; and the David and Goliath battles between American family farms and Big Ag megacorporations.

Inspired by novelist Jonathan Safran Foer’s 2009 nonfiction book of the same name, “Eating Animals” asks us why a society that would find a man who kicks a dog detestable has no baseline decency for the treatment of animals by factory farming. The animals producing the enticing flesh we find in supermarket display cases generally “endure lives of unmitigated cruelty from the moment they’re born until the moment when they’re slaughtered,” as the film’s producer and narrator Natalie Portman explains.

It’s a rather brave project, given the laws making it illegal in certain states to film farms raising our meat and dairy. Although Quinn repeatedly was asked to stop and move along, he wasn’t imprisoned.

His film tells its story persuasively through the experiences of whistleblowers such as veterinarian and scientist Dr. James Keen, who resigned from the U.S. Meat Animal Research Center in Nebraska, at huge personal cost, after witnessing practices he could not excuse.

Quinn’s footage shows us the abhorrent life span of chickens genetically engineered to die in six weeks, cows whose antibiotic overdoses cause their udders to rupture and the pus drain into the milk we buy, and swine crammed into concentrated feeding operations.

The new trend for North Carolina farmers contracted to corporate titans is to channel their pigs’ fecal runoff into Pepto-Bismol pink holding pools, even though that can pollute the area’s water supply. As one angler puts it, a recent runoff has caused “so many dead fish they were burying them with a bulldozer.” And the suffering caused by factory farming isn’t limited to animals. Quinn’s film also examines how raising animals in unnaturally crowded conditions can produce pathogens that replicate in humans like new strains of bird flu.

While the film notes that we can find all the protein we need in plants, it doesn’t argue that the nourishment, comfort and culture we find in meat will vanish overnight. It shows the humane practices of people like Frank Reese, a turkey farmer who raises his birds with considerable care and affection — though not enough to spare them from being sold for Thanksgiving dinner, a vegan might note. Some of the movie’s most beautiful cinematographic moments, beyond wonderful shots of rural landscapes and farms, are the scenes with Reese watching his turkeys running free.

Without declaring one specific solution to the challenges of animal agriculture, the film focuses needed attention on the issues. It finds instructive ideas about the state of America’s current diet in black-and-white archival footage of KFC’s Col. Sanders, but it doesn’t lecture or accuse anyone. As Portman puts it, “No one fired a pistol to mark the start of the race to the bottom. The Earth just tilted, and everyone slid into the hole.” Films like this can help return it to its axis.