March 13, 2007

SUPER SIZE ME II; Scientist Stages Experiment Based on the Movie — and is Surprised

By Kate Douglas

If you'd bumped into nursing student Adde Karimi last September, he probably wouldn't have had much time to chat. He was too busy stuffing his face with burgers, cola and milkshakes. It takes a lot of planning to get 6,600 calories of junk food down you in a day, he explains.

If you're not a born glutton, serious overeating also requires a high level of commitment. Karimi's motivation was commendable. "I did it because I wanted to hate this type of food," he says. He also did it for science.

Karimi was a volunteer in an experiment based on the 2004 documentary "Super Size Me." In the movie, filmmaker Morgan Spurlock spent 30 days eating exclusively at McDonald's, never turning down an offer to "supersize" to a bigger portion, and avoiding physical exertion. Karimi followed a similar regime, gorging himself on energy-dense food and keeping exercise to a minimum.

That's pretty much where the similarities end, though. By the end of Spurlock's McDonald's binge, the filmmaker was a depressed lardball with sagging libido and soaring cholesterol. He'd gained 11.1 kilograms, a 13 percent increase in his body weight, and was on his way to serious liver damage. In contrast, Karimi had no medical problems. In fact, his cholesterol was lower after a month on fast food than it had been before he started, and while he'd gained 4.6 kilos, half of that was muscle.

The brains behind this particular experiment is Fredrik Nystrvm, of Sweden's Linkvping University. In the past year, he's put 18 volunteers through his supersize regime. What fascinates him most is the discovery that there was such huge variation in their response to the diet.

Some, like Karimi, took it in stride. Others suffered almost as much as Spurlock, with one volunteer taking barely two weeks to reach the maximum 15 percent weight gain allowed by the ethics committee that approved the study. We're used to being told that if we're overweight, the problem is simply too much food and too little exercise, but Nystrvm has been forced to conclude that it isn't so straightforward. "Some people are just more susceptible to obesity than others," he says.

Nystrvm had been intrigued by Spurlock's experiment ever since seeing "Super Size Me" but was bothered by its unscientific nature. So when one of his Ph.D. students unexpectedly quit, freeing up some research money, he decided to have a go at replicating it under clinical conditions.

Things got off to a good start. Following one of his regular lectures to medical students on the perils of obesity, Nystrvm asked whether anyone would be interested in taking part in an experiment involving as much free food as you can eat. The response was very positive. As it happened, most of the volunteers were male. "The boys are very committed," says Nystrvm, "but it has been really tough to get girls to sign up." He wanted 10 of each, but in the end has had to settle for 12 men and six women.

The first batch of seven healthy, lean volunteers began their month-long challenge in February 2006. First, Nystrvm calculated their normal daily calorie intake, then asked them to double it in the form of junk food, while avoiding physical activity as much as possible.

Nystrvm allowed them to do just one hour of upper body weight training per week.

"I thought it would help some of the guys to stick to the diet if they believed that some of the extra weight could be in the form of muscle bulk," he says. Aside from that, though, they were encouraged to be as slothful as possible, and were issued with bus passes and pedometers to help.

In another difference from the movie, Nystrvm didn't order his volunteers to eat only at McDonald's. They were also allowed to eat pizza, fried chicken, chocolate and other high-fat food whenever they could no longer stomach burgers.

During the experiment, Nystrvm's volunteers had weekly safety check-ups to monitor their health. In addition, they were subjected to a barrage of tests and exams before starting the diet and afterwards to find out what it had done to their physiology, metabolism and mental health.

Nystrvm can't disclose the full results of his experiment until the study is published later this year. Even then, it will take years of analysis to coax the detailed implications from all the data.

The big mystery is weight gain. Why do some people pile on so much more than others while consuming the equivalent amount of food? Nystrvm's hunch is that it's down to variations in metabolism; some of us are simply better at handling calories than others. If you're lucky, your body can adapt to cope with an extra cream doughnut or even a blow-out dinner by burning off the excess energy in the form of heat. He suspects many of his volunteers fall into this category because they were all slim on their normal diet and because they often commented on feeling warm all the time while overeating.

If Nystrvm is correct, this is what makes his study so unusual and potentially valuable. Most research into obesity is done on people who are already overweight; in other words, those least resistant to calories.

The ability to turn excess food into fat has been an adaptive advantage throughout most of human evolutionary history when our ancestors had to deal with alternating feast and famine. But the erratic availability of food has not been the only factor influencing the evolution of human metabolism.

"In cold areas, people might have adapted more to cope with temperature and so be more likely to burn off excess calories as heat," says Nystrvm. People with this type of metabolism seem better able to cope with today's "obesogenic" world, and Nystrvm hopes that by studying them he will be able to identify new approaches to tackling the obesity epidemic. "Because we have such a huge amount of data we should be able to start teasing apart some of the influences that make some people more susceptible to obesity than others."

(c) 2007 Buffalo News. Provided by ProQuest Information and Learning. All rights Reserved.