You were as shocked as anyone by the results of your month long experiment of exclusively eating McDonald's food, weren't you?
"Absolutely. The only agenda I had going in was to make a film that would hopefully cause people to think about how they eat and live their lives. And that's what the film's done. It's done a great job of affecting the people who see it. If people walk out of the movie saying they need to think more about what they eat, about how they live, about exercising more. Parents are coming out and saying they need to be a better role model to their kids. They need to start cooking more at home, and are saying they will go to their kids' school and see what they hell they're feeding them because they have no idea. For me, that's the most terrifying thing in the movie, what we're feeding kids in schools in America."
How close did you come to calling it all off?
"By the twenty first day I was close. On day 21 when I was really sick, and felt miserable, and I woke up in the middle of the night with massive chest pains and couldn't breathe. I was really frightened at that point. When you have three doctors who are looking at your blood tests and comparing your liver to patÃ©, and looking at your cholesterol levels - at this point my uric acid levels had jumped up and I was giving myself hyper-uricaemia - you're looking at these things and three doctors are saying you have to stop because they don't know what's going to happen to you. That's not the advice you want to hear. Especially when in the beginning you had three doctors who said 'maybe you'll gain a little weight and your cholesterol will go up a little bit, but that's it'."
How much weight did you gain over the month?
"I put on 25 pounds, and it took me 14 months to get it all off. I've still got a little bit there that I'd like to get rid of. But it was tough. I'm sure I could have gone on a crash diet and lost it really quickly, said I wasn't going to eat anything, period, and just drunk water for a month. I'd have lost it like that."
But that would have been foolish after what you put your body through, wouldn't it?
"Exactly, that's what people don't realise. That's why part of the problem for me in America is all these crash diets. We just throw ourselves into this less than ideal situations of Atkins, no-carb low-carb, South Beach, all of them. Change your lifestyle, that's all you need to do."
What was the response of McDonald's employees when they saw you filming in store?
"It was amazing, we just walked right in and shot it. Once we left New York, which is more media savvy and media paranoid than most cities. When you walk in with a camera people tend to freak out more in New York than anywhere else. Once we left New York city most people didn't really care. These people were making five bucks an hour, if you're making that money what do they care? 'Do you want fries or not? Okay, great leave'."
Despite all the pre-publicity, and the defensive posturing of McDonald's, Super Size Me is not specifically about them is it?
"For me it's about this type of all-American lifestyle, this fast food culture that has permeated our whole way of life in America. And now we've franchised out all over the world. Now we've made this great way of eating and living, where we don't think of what we're shovelling in our mouths, and don't think of the quality of the calories that we eat. That's what's really taken over. For me, as much as I think the film is a wake up call for Americans, I think it is an immense wake up call for Europeans."
Once upon a time McDonald's would have been the good guys though, wouldn't they?
"Years ago they were making their own burgers on site. There would be someone who would make a beef patty in the place and put it on the grill. The bread was probably made by a local baker, and delivered to the store. French fries were actually potatoes when they were brought into the store, and were put through the shucker and into the deep fryer. That doesn't happen any more with the mass manufacture of their food. Patties are made thousands of miles away in the States. Fries are made in one of two factories in the United States, thousands of miles away from most restaurants. They're freeze dried, frozen, then shipped out, so the freshness of the food is gone. And the reason is because of uniformity. At one point McDonald's said they wanted their food to be exactly the same everywhere they went."
One of the shocking things in the film is when you demonstrate the physical size of the drinking cups and the containers that hold the fries.
"The largest size you have here is a medium in the US. That's almost one and a half litres of soda, or three and a half cans. What is the nutritional value of a Coke? It's incredible. I'm anxious to see what happens, because they say by the end of this year there'll be no more Supersizing, and my prediction is that every other company will follow suit. The Burger Kings and the Taco Bells, the 7-11s will all start to get rid of their big sizes and I'm sure they'll say something like consumer demand was lacking. They'll say people weren't buying them as much, or that it was too expensive to make the cups. They'll come up with some spin."
What was your reaction to the sudden death from a heart attack of McDonald's CEO Jim Cantalupo?
"That was unbelievable, wasn't it? He was 60 years old, that's not old. Charlie Bell the current CEO had prostate cancer, and now has colon cancer. Someone asked him if he thought there was any connection between the CEO having a heart attack and him getting cancer, and this food that those guys eat consistently. He said it had nothing to do with McDonald's food, these are just acts of God. I told that story to an Australian journalist and he said 'wow, God must be a vegetarian'."
There are many other areas you could have gone into with the film, aren't there?
"So many things, like aspartame, for example. They put it in Diet Coke, and a lot of other sodas now. That's now been shown to cause your brain not to realise that you're taking in calories, so you'll continue to eat and you'll continue to store fat."
What was the first great food you had after the month long experiment ended?
"The very first day, I went to this Japanese noodle shop right up the street from my office. They make the best Udon noodles, and I got a big bowl of Miso Udon noodles. The guy normally grabs a big handful of vegetables and throws it in there, and I said one more, and then another. I had this giant bowl of noodles and vegetables piled on there. You couldn't even see the noodles, there was so much green on there. Then that night my girlfriend Alex made a chili, this really fantastic vegetarian chili that was great. Those were the first two meals I had, and they were the best. But then right after that I went into withdrawal. Starting about midnight that night, the headaches came back and for about three days I went into massive withdrawal from the fat, sugar, caffeine and the immense sodium that's in this food."
What have McDonald's rivals had to say about the film?
"It was like, 'phewww, man I'm glad he didn't call on us'. The only reason I picked McDonald's is because they're the biggest, the industry leader and they influence this business like nobody else. So to hear them saying they're going to eliminate supersizing by the end of this year, my prediction is that you'll see Burger King and Wendys and the rest doing the same. But they'll say it's not profitable any more, that the cups cost too much or something."
Of course the irony is that cinemas sell nutritionally dubious food too, don't they?
"Yeah, but they sell it to you on the way in, so what do they care? If you go through the aisles after a Super Size Me screening the sodas are only half drunk, the cartons of popcorn are still full. But I love getting a nacho and a Coke when I go see a film."
Seeing audiences respond the film have you found they did so in all the right places?
"Absolutely, the response has been fantastic. Both during the screenings and afterwards, the film is affecting people. It's good."
Is it possible to draw a parallel between something like Jackass and what you're doing here, even though yours has a serious point to it?
"I think so. Just the whole idea of me eating this food for a month, people will make a comparison. But there is a difference, there is a much larger picture. When people go to see the film they come into it very underwhelmed because they think they've got it all figured out. A guy eats McDonald's for a month and gets sick - 'yeah I could have told you that!'. Then people see the movie and realise there's a lot more to it. Believe me, if it was just an hour and a half of me eating McDonald's, the only person who'd go see that would be my mother. But it's definitely having an impact and by being funny it has something that people may equate to Jackass. I think that's helped the film. A friend of mine saw the film in Dallas on a Friday night, a sold out screening in a multiplex that was also playing Troy and Van Helsing. Here was a sold out screening of Super Size Me on a Friday night, 9 o'clock, and he called me afterwards to tell me that half the audience were teenagers. That's great, because that's who needs to see the movie."
When did you first realise you had a phenomenon on your hands?
"Right before the Sundance Film Festival earlier this year we got some idea, because of the word of mouth that had already started to trickle out. After it started screening there, and we heard the response from audiences and critics, then I thought we had something."