With Hollywood backing and a stellar cast, a film of Eric Schlosser's best-selling book, Fast Food Nation is looming as a potent threat to the burger chain's fragile reputation.
A fictionalised account of the book, subtitled The Dark Side of the All-American Meal, the movie refers to a company called Mickey's and stars Patricia Arquette, Ethan Hawke and Avril Lavigne.
Although the plot is closely guarded, it tells the story of a group of young fast-food workers, in a small Colorado town with a meat-packing plant, who uncover some unsavoury truths about the burger business. The movie is unlikely to pull any punches, having been made by Participant Productions, the "political film" studio behind the oil thriller Syriana, that stars George Clooney.
A more pressing threat to the executives at McDonald's corporate headquarters in Oak Brook, Illinois comes from the publication next month of Chew On This, a youth spin-off of Fast Food Nation.
Aimed at teenaged children, a key market for the burger chains, the book takes young readers through the origins, methods and problems with fast food. It traces how McDonald's became a global empire after the brothers Richard and Maurice McDonald invented a no-frills factory line for food that eliminated the need for skilled chefs, waitresses, ceramic plates or cutlery. Businessman Ray Kroc popularised the brothers' Speedee Service System, turning McDonald's into a multinational with sales these days of more than $20bn a year.
Mr Schlosser's book discusses how McDonald's targets young children, the treatment of its "McJob" employees, the mass breeding and slaughter of its livestock, the relationship between burgers and obesity, and the preponderance of additives - he claims there are 40 chemicals in a strawberry shake.
Chew On This, which has been adapted for a British readership, challenges young readers to ask whether they really want to eat fast food. The introduction explains: "The food you eat ... helps determine whether you'll be short or tall, weak or strong, thin or fat. It helps determine whether you will enjoy a long, healthy life or die young.
"So why is it that most people don't think about fast food or know much about it?
"The simple answer is this: the companies that sell fast food don't want you to think about it. They don't want you to know where it comes from or how it's made. They just want you to buy it."
Reports from the US suggest that McDonald's has been rattled by the risk to its reputation. The corporation was stunned by the success of Super Size Me, in which the film maker Morgan Spurlock ate nothing but McDonald's for a month - turning his liver into "pâté" in the process.
This time, McDonald's plans to fight back. A "council of war" has been convened inside the corporation's global HQ, according to the US magazine, Advertising Age. "They're worried about a backlash," one insider was quoted as saying. "When the consumer sees the movie, they will react. It would only need to take consumers to cut back one or two visits to affect the bottom line."
McDonald's strategy is believed to involve emphasising customer choice, its new, healthier menu and its community links. "We are aware of Mr Schlosser's new book and movie ... The McDonald's family will vigorously communicate the facts about McDonald's, our people and our values," a US spokesman said. On Monday, reporters have been invited into McDonald's in Illinois for a briefing on the retailer's "commitment to quality food".
The moves come at a bad time for McDonald's in Europe, where sales dipped. In Britain, the company is closing 25 branches of its 1,000 outlets amid signs that teenagers are losing enthusiasm for its fatty products and plastic interiors.
Worldwide, McDonald's is performing well and expanding into new territories such as China. Global sales rose 5 per cent in the first quarter of this year.
McDonald's is a wounded giant, but the wound may yet turn out to be nothing more than a cut. As Tim Lang, professor of food policy at City University, said after the British closures became known last month: "McDonald's critics should be cautious about premature ecstasy ... These closures say more about demography than any decline in interest in fast food."
How Goliath failed to silence a host of Davids
* McDonald's has had plenty of bad publicity in recent years. Paradoxically, one of its biggest setbacks came when it won a long-running libel case against two British campaigners.
Rather than withdraw claims in a leaflet they had been handing out, Helen Steel, a former gardener, and David Morris, a former postman, fought McDonald's in a David-and-Goliath legal battle that lasted seven years. On one side was a high-powered legal team assembled by a multinational company. On the other were two unemployed activists.
The McLibel Two taught themselves law and called academics to give evidence on McDonald's impact on the environment, animal welfare, marketing and health. McDonald's won the case in 1997 and was awarded £60,000, cut to £40,000 on appeal. But the judge agreed with some of the McLibel Two's claims, on low wages, animal cruelty and the exploitation of children in advertising. Last year the European Court of Human Rights ruled that the case had been unfair to the McLibel Two because they had not had legal aid.
Their fight against McDonald's continues at Mcspotlight.org, a website run by volunteers in 16 countries.
In 2001, Fast Food Nation by Eric Schlosser subjected McDonald's to another thorough examination. Schlosser visited the laboratories where fast-food scientists recreate the smell and taste of everything from cooked meat to fresh strawberries and detailed the high level of additives in fries and milkshakes.
Two years ago, McDonald's faced a PR catastrophe with the release of Super Size Me. Director Morgan Spurlock ate only McDonald's for a month and doctors monitored the disastrous effect on his health. He put on 25 pounds in weight and one doctor begged him to stop eating McDonald's.