There are urban legends about McDonald's, the global United States-based fast food chain. McDonald's has a very high profile in much of the world, and, especially within the anti-globalization movement, is sometimes held as a symbol of the negative impacts of globalization.
Various large companies have been the subject of rumors that they substitute unusual or unethical substances in their products, usually to save a few cents per serving. McDonald's is not immune to such claims. The following is a list of the most popular rumors about their food products.
One common thread that ties many stories like these together, is the fact that they were not reported to the easily accessible mainstream media, police, medical services, or even government-run food or health inspection agencies, such as the United States Food and Drug Administration (FDA). These agencies and services are legally obliged to act on such extreme cases.
Other variants have credited other investigative journalism shows for the "shocker". Some versions of the tale have it being revealed in a talk show chat with company CEOs. However, some posit that neither McDonald's nor any other restaurant would use worms, for the simple reason that worms cost more per unit of weight  . While worm meat is considered very nutritious  , and contains no gristle, to use worms as filler would seem to be more expensive than using actual beef. McDonald's has gigantic shipments of meat it regularly orders from cattle farmers. If one were to suppose that worm meat were used, one would have to justify the small proportion of the U.S. population involved in worm farming (though it can be argued that as a result of globalization, it's not implausible to suggest that they might utilise international outsourcing to acquire the worm meat). At an Atlanta press conference, officials, backed by a regional officer of the U.S. Department of Agriculture, denounced the rumors as "completely unfounded and unsubstantiated", and swore that the company's hamburgers contain nothing but beef. From Newsweek, November 27, 1978. McDonald's released a letter from the U.S. Secretary of Agriculture in 1982, attesting to McDonald's burger's pure beef content. It was used as proof in a rebuttal press conference on October 1 of that year, against the rumor. Occasionally, the finger is pointed at Jack in the Box for using worm meat.
Another popular belief is that McDonald's widely uses cow eyeballs in its products, permitting it to brand them as "100% beef". However, the USDA mandates that all beef by-products, including cow eyeballs, be appropriately labelled. McDonald's, however, has asserted that its products contain "100% pure USDA inspected beef; no additives, no fillers, no extenders." In addition, cow eyeballs are actually more expensive than real beef, due to demand from scientific institutions for experiments. Also, a cow eyeball weighs only about an ounce, so it would take too many eyeballs to make up one burger to be worthwhile, though it is plausible that they could be used as filler.
Around March-April, 2000, an Internet rumor spread via e-mail in Brazil claimed that McDonald's meat was actually made from a genetically modified animal maintained in a laboratory. The e-mail stated that "the few who saw it assure it is a very unpleasant sight: they have no limbs or horns, no bones (undeveloped cartilage instead), no eyes, no tail and no fur; its head is about the size of a Baseball; they are fed through tubes connected directly into their stomach".
The e-mail carries on saying that "some irreversible health damage can be done by eating this meat, resulting in diseases who manifest themselves in a way similar to AIDS, and have symptoms related to Alzheimer's Disease" and ends encouraging the reader to boycott McDonald's until it sells actual beef.
The discovery was credited to researchers from the University of Michigan, although there are no official claims from anyone who actually works there. And is yet to actually be proven. So it was likely an April Fool's Joke, due to its date of publication.
Another rumor circulating on the Internet claims that a girl suffered a near death experience after eating a McFlurry. The rumor claimed that the girl was highly allergic to bird feathers. The family traced back the origins of all the food the girl had recently eaten. On phoning McDonald's head office, they were told what was in the dessert — feathers. However, this is an unsubstantiated urban legend; bird feathers are not a stated ingredient in its production.
There has often been a rumor that McDonald's uses pig fat in their milkshakes, ice cream and fried potatoes. McDonald's provides complete ingredient lists for all of its products on each of its regional websites: this includes unidentified fats within the ice cream used to make soft serve cones and sundaes. McDonald's Australia, however, specifically mentions that "No idea how this one got started, there is definitely no lard and pig fat in the McDonald's Soft Serve or potatoes.". This rumor should not be confused with the fact that McDonald's has in the past used beef tallow as its frying oil.
In Australia, a rumour has floated around for years that McDonald's Apple Pies were made of choko and ostrich eggs, not apples. This eventually led them to emphasise the fact that real Granny Smith apples are used in their pies. Choko are more expensive than the apples supplied to McDonald's Australia.
Another popular urban legend is that McDonald's gets their beef and related supplies from a company named 100% Beef so they can use the phrase 100% Beef in their advertising. Advocates of this rumor point out the fact that the word Beef is capitalized, suggesting this a trade name. In fact, there is no such company named 100% Beef, and the origin of this rumor is unknown at this time.