Revealing mistake: Near the end, when Morgan Spurlock says "Why not do away with your Super Size options?" the water condensation runs UP the drink. (01:34:00)
Factual error: Morgan says that french fries are one of the seven items on McDonalds menu that doesn't contain sugar. French fries, in fact, do contain dextrose - a form of sugar. This is mentioned on DVD commentary.
Chosen answer: Because it probably got some funding from the UK Film Council.
David Mercier