(RxWiki News) The contestant sheds his shirt before stepping on the scale before millions of television viewers watching 'The Biggest Loser'. Following week after week of sweating and running, what will the scale read?
By looking at contestants on the reality show, new research shows again that exercise and eating well together help lower body fat and save muscle in adults better than just diet alone.
The study also showed that participants could maintain the weight they lost by exercising moderately 30 minutes a day and lowering their calories by 20 percent, versus the intense exercise that was shown on the show, the researchers said.
"Every journey starts with a single step - take the stairs today!"
In the Biggest Loser, obese adults lose large amounts of weight as they undergo a combo of daily hardcore exercise with a strict diet over several months.
The study, led by Kevin Hall, PhD, looked at how the training programs used on the Biggest Loser affected 11 contestants.
"By including the show's contestants as voluntary study participants, this research took advantage of a cost-efficient opportunity to study a small group of obese individuals already engaged in an intensive lifestyle intervention," Dr. Hall said in a press release.
At the start of the program, researchers tracked contestants' body fat and how much energy they burned during exercise, as well as how much is burned while resting.
Researchers took the measurements again at weeks 6 and 30, which was a little more than four months before the participants returned home.
Dr. Hall and researchers used a computer model to figure out the exercise and diet changes causing contestants' obvious weight loss.
The show doesn't show how exactly exercise and diet help with weight loss, so the computer model simulated each of these separately to show how each would help.
On the show, the contestants lost an average of 128 pounds, 82 percent of which comes from fat.
The other weight lost comes from muscle and other lean tissues in the body. Keeping as much of the lean tissue as possible helps people keep strong, mobile, and lowers their chance of being injured.
Researchers found that diet was responsible for helping participants lose the most weight on the show.
Of the weight lost on average by the contestants on the show, 65 percent came from fat and another 35 percent from lean mass like muscle.
The model however found that exercise alone caused participants to lose only fat and increase lean muscle.
"If the contestants were to return to their original sedentary lifestyle and diet immediately after the competition, the model simulated a slow rate of weight gain," Dr. Hall said in his report.
"It takes many years to regain the lost weight because of the slow response time to changes in diet and physical activity."
Griffin Rodgers, MD, director of the National Institute of Diabetes and Digestive and Kidney Diseases, said that the study "reinforces the need for a healthy diet and exercise in our daily lives."
"It also illustrates how the science of metabolism and mathematical modeling can be used to develop sound recommendations for sustainable weight loss -- an important tool in the treatment of obesity -- based on an individual's unique circumstances," he said.
Dr. Hall has no financial ties and or affiliations to the show and declares no conflicts of interest.
The National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health, funded the study. It was supported by the Intramural Research Program of NIH.
The study was published online October 3 in the journal Obesity.