Following produce from seed to plate . . . to screen

“Fresh’’ can be so wearyingly upbeat you might want to heave a brick through a Whole Foods window once you leave the theater — or at least wash down a couple of Quarter Pounders with a Big Gulp of nothing but high-fructose corn syrup (free refills!). Except that there’s no arguing the case the documentary makes against industrial agriculture’s factory feedlots and manure lagoons.

And as impressive are the statistics cited (did you know that the US Department of Agriculture says that fresh produce grown in 1950 had 40 percent more nutrients and minerals than it does today?), what most stays with you is the whomp heard on the soundtrack when trays of chicks get tossed into an Arkansas henhouse that holds several thousand birds. Hen factory is more like it.

The documentary displays at times a reassuring hardheadedness that’s at variance with all the glowing testimonials and even more glowing visuals. The rhapsodic Virginia farmer notes that a neighboring non-sustainable farm generates $150 per acre in income annually, while his generates $3,000 per acre. A sustainable hog farmer from the unfortunately named locale of Frankenstein, Mo., points out he doesn’t have to pay a penny for antibiotics and pesticides.

Most persuasive of all is Michael Pollan, author of “The Omnivore’s Dilemma’’ and “In Defense of Food.’’ “It is true local and organic food costs more,’’ Pollan says. “It’s worth more, too.’’ Expense, he notes, is a relative thing. “There is no such thing as cheap food. The real cost of the food is paid somewhere. If it isn’t paid at the cash register, it’s charged to the environment, it’s charged to the public purse in the form of subsidies, and it’s charged to your health. You do get what you pay for, with food as with anything else.’’ Like all the best secular evangelists, Pollan grounds his fervor in facts.

So “Fresh’’ may be righteous (as well as right), but it’s not unrealistic. In the realm of advocacy documentary, that’s no small thing. Also, let the record show, not once in the course of the movie is the word “locavore’’ used.

Mark Feeney can be reached at mfeeney@globe.com.