Big Mac attack: Super Size Me asks the question: is McDonald's unappealing--or irresistible?

During the first lunch of his month-long McDonald's binge, Morgan Spurlock is visibly uncomfortable. Eating in his car after stopping at a drive-through, he has trouble finishing his supersize fries. He complains of "a McBelly ache," "McGas," and "McSweats." Then he leans out the window and vomits on the asphalt.

Since Spurlock's documentary Super Size Me argues that fast food is addictive, perhaps this scene is a sly reference to the nausea people often experience the first time they inject heroin. On the face of it, however, Spurlock's reaction undermines his thesis that fast food is so irresistible that people can't help but gorge themselves on it. Super Size Me (in which I briefly appear) is full of such contradictions, and they're the best thing about the movie.

Spurlock's fast food feat consists of eating some 5,000 calories a day, twice what his doctor says he needs to maintain his starting weight of 185 pounds. He also avoids exercise because, he says, that's what most Americans do. I hope I'm not ruining the movie by revealing the upshot: Spurlock gains weight--nearly 25 pounds over 30 days. His cholesterol goes up, and so does his blood pressure. His doctor describes his liver function test results as "obscene." Spurlock complains of sluggishness, depression, shortness of breath, impotence, chest pressure, and headaches. Again, this experience does not seem so alluring that people would be clamoring to share it.

After nine days, Spurlock announces, "I'm pretty bored with their menu." When it's all over, he says with relief, "I can't believe that today I'm going to get up and not have to eat at McDonald's." Yet Spurlock also claims he was hooked on fast food during his binge, feeling happy only while eating. "I definitely went through serious withdrawal symptoms," including headaches, sweats, and shakes, he reported atthe Washington, D.C., International Film Festival in May.

You could say Spurlock's experience reflects the reality of addiction: It's not something you fall into; you have to work hard at it. As the psychologist Jeffrey Schaler has observed, it takes "an iron will" to be an addict. But this understanding of addiction--as a choice, not a disease--works against Spurlock's attempt to blame fast food chains for making us fat.

Spurlock detracts from his message in other ways as well. Although he generally presents critics of McDonald's as public-spirited activists, he can't resist taking a shot at Samuel Hirsch, the lawyer who filed the first two obesity lawsuits against fast food restaurants. When Hirsch is asked his motive for getting involved in such litigation, he looks puzzled. "You mean, motive besides monetary compensation?" he says. "You want to hear a noble cause?" That's his only appearance in the film.

Spurlock also has a bit of fun with litigation enthusiast John Banzhaf, who somberly explains how fast food chains, like tobacco companies, "lure young children," teaching them to associate their brands with positive images and happy experiences. Spurlock deadpans, "That's why, when I have kids, every time I drive by a fast food restaurant. I'm going to punch my kids in the face."

Spurlock uses humor to advance his thesis too. He shows pictures of famous personalities to kids who look to be about 6. They readily identify Ronald McDonald and George Washington but are stumped by a third picture. "George W. Bush?" one little boy ventures, "No, but that's a good guess," says Spurlock, turning the picture toward the camera. It's a drawing of Jesus Christ.

As with Spurlock's exercise in extreme eating, I'm not sure what that proves. The fact that kids know who Ronald McDonald is does not mean they will end up gorging themselves, Spurlock-style, and become dangerously overweight.

Similarly, Spurlock asks a group of tourists to stand in front of the White House and recite the Pledge of Allegiance, which they have trouble doing accurately and in unison. But when he asks about the components of a Big Mac, one of them wattles off, "Two all-beef patties special sauce lettuce cheese pickles onions on a sesame seed bun." I can recite that list too, but I've never eaten a Big Mac.

Presumably these tests are meant to illustrate the "toxic food environment" that Yale obesity expert Kelly Brownell, who appears in the movie, blames for Americans' bulging bellies. Brownell's message--that we will continue getting fatter as long as food is cheap, tasty, readily available, and heavily promoted-is not exactly empowering. Super Size Me implicitly criticizes Jared Fogle, the formerly 425-pound star of Subway commercials, for offering impractical, simplistic weight loss tips. But what Fogle tells an overweight girl after a speech seems like good advice to me: "The world's not going to change. You have to change."

Senior Editor Facob Sullum ([e-mail]) is the author of Saying Yes: In Defense of Drug Use (Tarcher/Penguin), now out in paperback.