ST. LOUIS — Washington University is taking the 2004 movie "Super Size Me" a step further.
The St. Louis-based university wants to determine why some obese people have obesity-related sickness and others don't. The St. Louis Post-Dispatch reports that over the course of a four-month study, participants will eat fast food and increase their weight 5 percent.
The study is funded by the National Institutes of Health.
Filmmaker Morgan Spurlock spent a month eating only at McDonald's for his 2004 movie "Super Size Me." For the Washington University study, participants will eat Big Macs, too, but also Whoppers, shakes and other fast food items. Volunteers will consume foods from McDonald's, Burger King, KFC, Taco Bell and Pizza Hut, adding 1,000 excess calories a day to their normal diet.
"We're using fast food because we know the calorie content and the calories are easier to keep under control," said chief researcher Samuel Klein. "We know how much fat, protein, carbohydrates are in those foods."
About one-third of people who are considered obese never get high blood pressure, diabetes, high cholesterol and other conditions associated with their weight.
"If we could find out why some people are resistant to the adverse metabolic effects of obesity, we might be able to develop better therapies and medications to break the link between obesity and metabolic diseases, such as diabetes and heart disease," Klein said.
More than one-quarter of adults were considered obese in the U.S. in 2009, according to the U.S. Centers for Disease Control and Prevention. An additional 36 percent were overweight. Obesity-related medical costs are approaching $100 billion annually, and about half of it is paid by Medicaid and Medicare.
"Obesity is a very expensive disease," said Klein, head of the university's Center for Human Nutrition and medical director of the Weight Management Program. "It's driving many of the diseases that are burdening our health system."
The study seeks 30 test subjects: 15 who don't have metabolic problems and 15 who do. A larger follow-up study is possible.
The volunteers will visit the medical school once a week, where researchers will test their fat cells, hormones and blood to find clues. People considered morbidly obese won't be in the study. Study manager Mary Uhrich said participants will be closely watched with a brief medical exam weekly.
Ginger Meyer, a registered dietitian with the Missouri Dietetic Association and the Weight Treatment Center in Jefferson City, voiced cautious optimism about the study.
"There's a benefit to knowing why some people have (metabolic problems) and others don't; that's a worthwhile question," Meyer said. But, "it's important to not be put at risk in terms of the weight gain," she said.
Klein said that if a patient develops a metabolic illness because of the study, he or she will be pulled out and put in a weight loss program.
Meanwhile, after the study, participants will be enrolled at no cost in a six-month weight loss program managed by Washington University. In the end, they're expected to lose more weight than they gained.
"They'll come out with a picture of their health they never would have seen otherwise," Klein said. "They'll be healthier when they finish than when they started."