''It's not like I'm some leftist guy setting the arches on fire,'' swears Morgan Spurlock, director and star of this upcoming fast-food exposé. He likes his Big Macs as much as the next guy. But when the filmmaker read about the two obese girls who unsuccessfully sued McDonald's in 2002 for their poor health, he launched an investigation into the responsibilities of fast-food companies and the inherent dangers of supersize diets.
For one month, Spurlock ate every meal at McDonald's, and in the process gained 25 pounds, lost his sex drive, suffered extreme mood swings, and experienced heart pains so bad ''it was like somebody put cinder blocks on my chest.'' (All to the disgust and dismay of his vegan chef girlfriend.) But was it ever worth it. His documentary, on a buzz-building stampede since he won the Best Director award at Sundance, has made a muckraker out of Spurlock. ''A kiddie cup is 12 ounces of soda,'' he fumes. ''That little tiny cup is a can of soda! Wouldn't it be great if all the fast-food restaurants were like, 'We're just going to do away with the supersize portions.''' In February, denying that the documentary had any influence over its decision, McDonald's did just that.